The Complete Human Body Dr Alice Roberts

449

RESPIRATORY DISORDERS

ACUTE BRONCHITIS CHRONIC OBSTRUCTIVE PULMONARY DISEASE

Inflammation of the bronchi is usually Chronic obstructive pulmonary disease (COPD) refers to long-term narrowing of the airways, causing
due to infection by viruses or bacteria, obstruction to airflow through the lungs, which leads to shortness of breath. It consists primarily of chronic
causing a hacking cough, and typically bronchitis and emphysema, which often coexist in the same person and are usually caused by smoking, or
clears up within 2 weeks. less commonly, by occupational exposure to dusts or fumes (for example, in the mining or textile industry).

Acute bronchitis typically follows a cold or flu CHRONIC BRONCHITIS X-ray, and analysis of the sputum. Supplemental in chronic bronchitis are usually viral, but
and is more common in smokers. It starts with oxygen may be needed, and inhalers are often antibiotics are used if a bacterial infection is
a dry cough that a few days later becomes Chronic inflammation of the bronchi with prescribed to relax the muscle of the bronchial suspected. Many people benefit from disease
“productive,” bringing up green, yellow, or gray excessive mucus production leads to walls, but airway obstruction is often irreversible. education, physical training, nutritional
sputum. Symptoms may include a general obstruction in the airways of the lungs Smoking cessation is vital. Oral corticosteroids assessment, and psychological intervention.
feeling of being unwell, fatigue, fever, shortness and a cough that produces sputum. may help acute exacerbations. Annual flu
of breath, and wheeziness. Sometimes a chest vaccination is recommended. Chest infections Infected Bacteria
X-ray may be needed and sputum sent off Chronic bronchitis is defined clinically as a mucus
for microbiological analysis. Because 90 percent persistent cough that produces sputum for at
of cases are viral, antibiotics are usually not least 3 months in 2 consecutive years. It is most Mucus Mucus Damaged
needed. People with bronchitis are advised common in men over 40 years of age who have Cilia gland layer cilia
to stop smoking, drink fluids, and rest. smoked regularly over a long period of time.
Noninfective bronchitis may be caused by lung Typically, the cough is worst in damp, cold
irritants such as smog, tobacco smoke, and weather, producing a clear white sputum.
chemical fumes.
Over time, increasing shortness of breath
Inflamed develops and there are frequent and repeated
tissue lining chest infections, with the sputum turning green
or yellow, accompanied by worsening of the
Thick mucus shortness of breath and wheezing. Eventually
there is progressive heart and respiratory failure
Narrowed (which has a poor prognosis) causing weight
lumen gain, cyanosis (a blue tinge to lips and fingers),
and swollen ankles (edema). Investigations
include blood tests, lung function tests, chest Normal airway lining Airway in chronic bronchitis
Glands produce mucus to trap inhaled dust and The mucosa is swollen and there is excessive
microbes. Tiny hairs (cilia) on the cells move to mucus production, leading to airway obstruction.
propel the mucus up into the throat, to be The cilia are damaged so mucus is not propelled
coughed up or swallowed. along adequately, thus encouraging infection.

Inflamed bronchus EMPHYSEMA muscles to dilate (widen) the airways, inhaled lung volume reduction surgery or lung transplant
Infection of the mucosa leads to inflammation steroids, and oral corticosteroids. The person may be offered. Pulmonary rehabilitation—
that narrows the lumen, along with excessive Destruction of alveolar (air sac) walls, may need supplemental oxygen from time to disease education, advice, and physical training
production of mucus that is filled with white caused by emphysema, reduces the areas time or continuously. Gastric reflux and allergies to improve lung functon—is often beneficial.
blood cells to fight the infection. for gas exchange and causes the small may exacerbate the condition. In severe cases, Annual flu vaccination is recommended.
airways to collapse during exhalation.
SPIROMETRY Alveolar Enlarged
wall alveoli
A lung function test called spirometry
measures the volume and/or speed of Emphysema is usually caused by smoking but
the air during inhalation and exhalation. can be due to a rare inherited disorder called
Peak expiratory flow rate (PEFR) of air from alpha-1 antitrypsin deficiency. It is most
the lungs gives a measure of obstruction in common in men over 40 who have smoked
the airways. Regular monitoring using this over a long period of time. Emphysema causes
test may be carried out in people with progressive shortness of breath. A cough
asthma (see p.450) and COPD (see right) without sputum may occur in the late stage.
to measure disease activity and any People with emphysema lose weight; their
response to treatment. lungs over-inflate, leading to a characteristic
barrel-shaped chest; and they often breathe
through pursed lips. Alveolus Collapsed
alveolar
Diagnostic investigations include arterial Healthy tissue walls
blood gas analysis, lung function tests, and The alveoli (air sacs) in the lungs are grouped like
chest X-ray. A CT scan may show characteristic a bunch of grapes. Each air sac is partly separate Damaged tissue
holes (bullae) in the lungs. To prevent further from the others. Their elastic walls help to push The alveolar walls have been destroyed, with
irreversible progression, smoking cessation and air out during exhalation. a resulting decrease in elasticity. The alveoli
avoidance of cigarette smoke and lung irritants are enlarged and fused together, reducing the
is vital. Treatments include short- and available area for gas exchange.
long-acting inhalers that act on bronchial

450

DISEASES AND DISORDERS

dander, and pollens), medications, exercise, Lumen Mucus Relaxed Narrowed Increased Inflammation
viral upper respiratory tract infections, stress, smooth lumen
inhaled dusts or chemicals. muscle mucus and swelling

ASTHMA An asthma attack causes the sudden onset Contracted
of shortness of breath, chest tightness, smooth
Reversible narrowing of the airways of wheezing, and coughing. Between attacks, muscle
the lung, asthma is due to long-term some people may have much milder
inflammation and leads to episodes of symptoms such as chronic coughing at night, Healthy airway Airway in asthma
chest tightness and shortness of breath. mild chest tightness, and shortness of breath The smooth muscle is relaxed and does not The smooth muscle is contracted. The lining
on exertion. Asthma is usually confirmed by contract readily in response to triggers. There is a of the airway is inflamed and the mucus layer
Asthma affects around 7 percent of people and spirometry testing and peak flow readings thin coating of mucus covering the lining of the thickened. The lumen is narrowed, causing
often runs in families. It often starts in (see p.449) that confirms the reversibility of the airway. The passageway for air (lumen) is wide. wheezing and shortness of breath.
childhood but can develop at any age. People airway narrowing. Treatment includes avoiding
with asthma have recurrent attacks when the triggers and use of inhaled medication to
muscle in the walls of the airways contracts, relieve symptoms. Mild asthma requires
causing narrowing. The narrowing of the short-acting reliever inhalers that directly dilate
airways is reversible, and some people with the airways. Regular inhaled steroids (preventer
asthma only rarely experience symptoms, inhalers) are used for more persistent symptoms.
usually in response to the common asthma Oral corticosteroids are used for severe cases.
triggers such as allergens (dust mites, pet

PNEUMONIA breathing, coughing up bloody sputum, fevers, TUBERCULOSIS months. If left untreated, TB causes the death
chills, sweating, feeling unwell, and chest pain. of half of those infected. Drug-resistant TB is
Inflammation of the alveoli (tiny air sacs) A chest X-ray is usually done to confirm the A bacterial infection mainly affecting the now an increasing problem. Vaccination is
of the lung, pneumonia is usually due to diagnosis. Sputum and blood may be sent for lungs, tuberculosis (TB) is major global rarely used in the US against this condition,
infection, but it can also be caused by microbiological analysis. Treatment is by taking health problem. Around one-third of the and is only 50 percent effective.
chemical or physical injury. the appropriate antibiotic. Bacterial pneumonias world has latent tuberculosis infection.
resolve within a month with treatment, viral Tuberculosis
Infective pneumonia is most common in babies pneumonias take longer. Pneumonia that is Tuberculosis (TB) is spread by inhaling tiny cavity
and the very young, smokers, the elderly, and caused by inhaling any substance into the lung droplets of fluid from the coughs or sneezes
people whose immune system is suppressed. is aspiration pneumonia. of an infected person. Most people are able Bronchiole
It is caused most commonly by the bacterial to clear the bacteria, some develop active Cavities in the lungs
infection Streptococcus pneumoniae and may White blood cells Fluid-filled disease, others develop latent TB with no In active pulmonary TB cavities are often seen in
affect areas of just one lobe of a lung. Viral alveoli symptoms but around 10 percent of these the upper lungs. These are areas of necrosis (cell
pneumonias are commonly due to the will develop the active disease in the future. and tissue death). Passage of air between infected
viruses that cause colds, flu, and The bacteria multiply very slowly and may tissue and bronchi releases TB into the airways.
chickenpox. Symptoms include take years to cause symptoms.
shortness of breath, rapid
Pulmonary TB causes symptoms such as
Inflamed alveoli a chronic cough with sputum that may be
The air spaces fill with fluid bloody, chest pain, shortness of breath, fatigue,
containing white blood cells that weight loss, and fever. TB may spread to the
kill bacteria. The fluid accumulates lymph nodes, bones and joints, nervous
and reduces oxygen absorption. system, and genitourinary tract. It is treated
using a combination of antibiotics, over many

INTERSTITIAL LUNG silica, asbestos, or beryllium. Sometimes no SARCOIDOSIS (reddish, painful, tender lumps), and red or
DISEASE underlying cause can be found. Symptoms brown papules (raised bumps on the skin).
usually develop gradually over many years and A multisystem disease, sarcoidosis is Common eye problems with this condition
A variety of diseases can affect the tissue include shortness of breath on exertion, a dry characterized by small inflammatory include uveitis and retinitis (see p.447). General
and space around the alveoli and are cough, and wheezing. The fingernails may nodules (granulomas) that affect the symptoms include weight loss, fatigue, fever,
distinct from obstructive airway diseases. become clubbed with increased convexity of lungs and lymph nodes. and generally feeling unwell.
the nail fold and thickening of the end part of
Most types of interstitial lung disease (ILD) the finger. Lung function tests, and high Sarcoidosis usually affects 20–40 year-olds Sarcoidosis can affect any organ including
involve fibrosis (development of excess fibrous resolution CT scan of the thorax are used in the although it may occur at any age and is most the heart, liver, and brain. If the lungs are
connective tissue). ILD usually affects adults and diagnosis. A lung biopsy (tissue sample) may be common in northern Europe. It is an affected it can lead to progressive lung fibrosis,
may be caused by drugs (such as chemotherapy needed; this is usually done via a bronchoscope autoimmune disease and the exact cause is and around 20–30 percent of those with the
and some antibiotics), lung infection, radiation, (a tube inserted through the airways). Treatment unknown. Many people with sarcoidosis have condition develop permanent lung damage.
connective tissue disease (for example, depends on the underlying cause, however the no symptoms, some have lung symptoms such Many people do not need any treatment, and
polymyositis, dermatomyositis, SLE and fibrosis is generally irreversible. Specific as a dry hacking cough and shortness of the symptoms disappear spontaneously. Severe
rheumatoid arthritis) and environmental or environmental causes of the disease should be breath, or eye or skin problems. Typical skin symptoms are treated with drugs such as
occupational exposure to chemicals such as avoided. In occupations where lung disease is a lesions include plaques, erythema nodosum corticosteroids. Most people recover fully within
risk, protective clothing and masks should be 1–3 years, but around 10–15 percent develop
worn. Smoking cessation is advisable. chronic sarcoidosis with periods of increased
severity of the symptoms and exacerbations.

451

RESPIRATORY DISORDERS

can be confirmed by chest X-ray. Symptoms of has entered the pleural cavity, the lungs need

PLEURAL EFFUSION PNEUMOTHORAX the condition include sudden shortness of to be decompressed by insertion of a hollow
breath and chest pain. A small pneumothorax needle through the chest wall or by the
Accumulated excess fluid in the pleural
cavity, a pleural effusion has a variety of may resolve by itself. If a large amount of air insertion of a chest tube.
causes and may interfere with lung
expansion, causing shortness of breath. A pneumothorax occurs when air or gas

The pleural cavity is the lubricated space enters the pleural cavity and causes the Air Bronchus Chest wall Lung collapses Pressure
between the two pleura (the layers of lung to collapse, leading to chest pain enters Pleural pulled out inwards balance
membrane lining the lungs and innter chest and shortness of breath. membranes maintained
wall). Excess fluid within the cavity causes lung Rib Pleural
shortness of breath and, if the pleura is irritated A pneumothorax may occur Pressure space
(pleurisy), sharp chest pain typically worse when spontaneously (more commonly balance
breathing in. Common causes include heart in tall, thin young men) or following
failure, cirrhosis, pneumonia, lung cancer, a chest trauma or lung diseases, Rupture
pulmonary embolus, TB, and autoimmune site
diseases such as systemic lupus erythematosus
(SLE) and rheumatoid arthritis. The fluid may be including asthma, chest
removed with a hollow needle, and examined
to investigate the underlying cause. infections, tuberculosis, cystic

Large effusions may be drained by inserting fibrosis, interstitial lung
a tube through the chest wall. Recurrent
effusions may be prevented by adhering the diseases, and sarcoidosis.
pleural surfaces together (pleuradhesis)
chemically or surgically. Penetrating trauma may cause

a tension pneumothorax

where, with each breath,

more air is sucked into the

pleural cavity pushing the Normal breathing Collapsed lung
heart and surrounding As the chest wall expands, it lowers the pressure Air from the right lung leaks out into the pleural
structures to the other side of within the pleural space and the lung, acting space and the lung deflates, no longer acting as a
the chest. This can be fatal effectively as a sealed unit, is pulled outwards sealed unit the lung cannot be pulled outwards by
without urgent treatment and by the pressure difference. the pressure difference.

Accumulation of fluid PULMONARY EMBOLISM (cyanosis), collapse, and shock. Usually Pulmonary
it is diagnosed by specialized CT scanning. artery
Pleural effusion A blockage to a pulmonary (lung) artery Treatment is with anticoagulation (“blood-
This colour-enhanced chest X-ray shows a large is usually caused by a thrombus (blood thinning”) drugs (typically heparin and Embolus
left-sided pleural effusion, which obscures the clot) breaking away from a deep vein warfarin). Severe cases may require traveling
view of the border of the left side of heart and fills thrombosis (DVT) in the leg. thrombolytics to break up the clot, or the to lung
the lower part of the left chest. clot may be removed surgically, a procedure
A pulmonary embolism is a blockage in lung known as pulmonary thrombectomy.
arteries caused by an object not normally Untreated, 25–30 percent of people with
found circulating in the blood. Rarely this may pulmonary embolism die.
be air, fat, or amniotic fluid (in pregnancy) but
is usually a clot from a deep vein thrombosis Right atrium
(see p.456). Symptoms include shortness of
breath, chest pain worse on breathing in, Path of embolus
and the coughing up of blood. Severe cases Right ventricle
may cause blueness of the lips and fingers
Pulmonary embolism
The clot travels from the deep vein of the legs to
the right atrium (chamber of the heart), then into
the right ventricle and into the pulmonary artery.

LUNG CANCER smoking) is a risk factor for non-smokers. NSCLC is often removed surgically, which may
Rarely, lung cancer may be caused by asbestos, be curative. Only around 25 percent of lung
A malignant tumor that develops in the toxic chemicals, and radon gas. By the time cancer patients survive for more than a year
tissue of the lungs is the most common of diagnosis, most lung cancers have spread after diagnosis.
cause of cancer death worldwide. elsewhere. Symptoms include a persistent
cough or a change in the regular coughing White blood cell
Primary lung cancer arises from within the pattern, coughing up blood, chest pain,
lung. There are two main types: small cell lung wheezing, shortness of breath, fatigue, Alveolus
cancer (SCLC) accounts for 20 percent of all weight loss, loss of appetite, hoarseness, and
cases, the rest are non-small cell lung cancer difficulty swallowing. Carcinogens
(NSCLC). SCLC is more aggressive (spreads
faster). Lung cancer occurs mainly in people Diagnosis initially is made by chest X-ray Spreading cancer cells Capillary
over 70 and 90 percent of cases are due to and a scan of the chest and is confirmed by
smoking. The risk is related to the number of biopsy (tissue sample) typically taken using Cigarette smoke contains carcinogens (chemicals that
cigarettes smoked and for how long. Breathing bronchoscopy (a tube is passed through the
in other people’s cigarette smoke (passive mouth into the lungs). Treatment depends on promote cancers) that are inhaled. These carcinogens
the type, site, and spread of the tumor. SCLC
is usually treated with chemotherapy and enter the blood from the alveoli to reach other sites.
radiaton therapy and has the poorer prognosis.

452

DISEASES AND DISORDERS

CARDIOVASCULAR DISORDERS

The heart and circulatory system are affected by many diseases, and cardiovascular disease is
the leading cause of death in the US. Lifestyle factors such as diet are important risk factors,
but some disorders result from structural abnormalities such as defects in the heart valves.

ATHEROSCLEROSIS the artery, blocking the blood flow completely. ANGINA with associated breathlessness. It usually comes
In the coronary arteries (which supply the on with exertion and eases with rest or use of
Fatty deposits and inflammatory debris, heart), atherosclerosis can cause angina or a Inadequate blood supply to the heart vasodilator drugs (drugs that widen the arteries
deposited as plaque on artery walls over heart attack; in the brain, stroke or dementia; itself, from the coronary arteries, can and let blood flow more easily). Longer-term
many years, lead to atherosclerosis or in the kidneys, kidney failure; and in the legs, lead to angina—pain resulting from too treatments include lifestyle changes, control of
narrowing of the arteries. claudication. The disorder can be slowed, little blood reaching the heart muscle. atherosclerosis, nitroglycerine, aspirin, and a
halted, or even reversed by stopping smoking beta-blocker drug to protect the heart.
Atherosclerosis can begin in childhood, even and lowering cholesterol and blood pressure. Angina is usually caused by narrowing of Occasionally, surgery or angioplasty are needed
in healthy people, although risk factors coronary arteries due to atherosclerosis (see to widen or bypass narrowed arteries.
including high cholesterol, smoking, obesity, Atheromatous plaques left), but a thrombus (clot), artery wall spasm,
high blood pressure, and diabetes increase its The fatty deposits and inflammatory reaction in anemia, exertion, fast heart rate, and other Why angina occurs
rate of development. Fatty deposits build up the artery lining cause a restriction within the heart disease may also be factors. Angina is felt Pain arises when part of the lumen (inner channel)
in artery walls, forming clumps, or plaques, blood vessel before eventually in the chest, neck, arms, or abdomen, often of a coronary artery becomes so narrow, due to
known as atheromas. These plaques stimulate rupturing, blocking the atheroma and spasm, that the area it supplies is
inflammation that damages an artery’s muscle artery completely. temporarily starved of blood and oxygen.
wall, causing it to thicken. Blood flow is
restricted, and tissues beyond that point Fatty deposit Blood enters heart
are starved of oxygen and nutrients. through coronary arteries
Eventually the plaque may break off in Muscle layer
of artery Artery narrowed
Red blood cell Inner lining by atherosclerosis
of artery
Arterial branch junction Area of heart Blood supply to heart
affected muscle is reduced
Fatty core of plaque
Fibrous cap by lack of Damaged heart muscle
oxygen If blood flow and oxygen supply are
Narrowed arterial channel restricted over a long time by myocardial
Outer protective infarction, some heart muscle fibers die,
layer of artery and the pumping action is impeded.

Restricted blood flow
Atherosclerosis can often start in a damaged area
of artery wall. As a plaque forms and the wall
becomes inflamed the area thickens, reducing
the space inside and restricting blood flow.

ANGIOPLASTY Stent Widened stent Increased flow
Flattened atheroma
This procedure is used to widen narrowed Atheroma Inflated balloon Stent remains
arteries in the heart and elsewhere in the Deflated balloon in place
body. Angioplasty is often used to treat
severe angina or after a heart attack. Under Narrowed area 2 Balloon inflated 3 Catheter removed
local anesthetic, a tiny balloon is inserted The positioning of the balloon Once the stent has been expanded
into the artery to push open the narrowed Catheter catheter is monitored by X-ray imaging. to the correct width, the balloon is deflated
area. A mesh tube called a stent may also be Once in the correct place the balloon and the catheters withdrawn. The stent
inserted to hold the artery open. 1 Catheter inserted is inflated, expanding the stent and remains in place and the catheter is
A guide catheter is fed through an pushing the artery open. removed from the body.
There are several techniques, and types of incision in an artery in the leg or arm until
stent, used for a variety of atherosclerotic its tip reaches the coronary artery. It carries
problems. Some stents are coated with a balloon catheter, covered by a stent, to
drugs to help prevent plaques from forming the narrowed area.
again. Aspirin or other anti-clotting drugs
are given following angioplasty, to reduce
the risk of clots.

453

CARDIOVASCULAR DISORDERS

HEART ATTACK Aorta Blood clot Coronary thrombosis
Narrowed artery The red patch in this angiogram
A myocardial infarction (MI) or heart Superior is a thrombus, or blood clot, that
attack is caused by complete blockage of vena cava Necrotic (dead) muscle fibers has formed in a coronary artery.
a coronary artery or one of its branches.
Pulmonary Damaged muscle
The term myocardial infarction means death of artery Enzymes released
part of the heart muscle. When a coronary
artery becomes blocked, usually from a Right Enzyme release
ruptured atheromatous plaque or a thrombus coronary The heart muscle
(clot), the area of muscle that it supplies is releases enzymes
starved of oxygen and dies. The extent of artery that can be
damage and complications depend on the measured to assess
artery involved; larger arteries supply larger Left main cardiac damage.
areas of muscle, and MI of large arteries are coronary
more likely to cause death. Damaged heart muscle
artery After a myocardial infarction, the dead
An MI typically causes central chest pain, area of cardiac muscle shrinks and
although those with diabetes may experience Site of scars, reducing heart function.
no symptoms at all (“silent MI”). The diagnosis blockage
is confirmed by ECG (a trace of the electrical
activity of the heart) and raised blood levels of Blood supply to
cardiac enzymes—chemicals released by the vessels blocked
damaged muscle. Urgent treatment with Myocardial infarction
“clot-busting” drugs or angioplasty can clear When muscle dies in a myocardial
the blockage, restoring blood flow. Other infarction, the heart may fail to pump
treatments include beta-blocker drugs to effectively or may stop beating.
protect the heart from arrhythmias (see below)
and aspirin to prevent further clots.

HEART RHYTHM SA node Blockage HEART FAILURE
DISORDERS
Atrium Some Failure of the heart to pump blood
An abnormal heart rate or rhythm is AV node impulses effectively can occur as a result of a heart
caused by a disturbance in the electrical Ventricle cross from attack, valve damage, or drug therapies
system that controls the way the heart healthy side used for other medical conditions.
muscle contracts.
Sinus tachycardia Bundle-branch block The heart pumps blood to the lungs to pick up
The signal to the heart to contract is driven by In this condition the heart rate of more than 100 The sinoatrial node impulses are partially blocked, oxygen, and to the tissues to deliver oxygen
electrical pulses from the sinoatrial (SA) node, beats/minute and a normal rhythm may simply be slowing the ventricular contractions. In total heart and nutrients. When the heart fails as a pump,
a natural “pacemaker” in the right atrium. It due to anxiety or exercise, but can also occur in block, no impulse gets to the ventricles, so they it causes symptoms of breathlessness, fatigue,
travels across both atria (upper chambers) via fever, anemia, and thyroid disease. contract at a rate of only 20–40 beats/minute. and edema (excess fluid in the tissues). In
the atrioventricular node, through the septum, addition, organs such as the liver and kidneys
and across the ventricles (lower chambers). Irregular Circular do not receive enough blood and start to fail.
Arrhythmias (abnormal heart rhythms) occur impulses impulses Heart failure can be acute (sudden), often
because of poor signal transmission or through atria resulting from a heart attack, or chronic
abnormal electrical activity. In atrial fibrillation (long-term), due to persistent disorders such
(AF), one of the most common forms of Variable Damaged as atherosclerosis, hypertension, chronic
arrhythmia, abnormal “pacemaker” sites blockage at heart obstructive pulmonary disease, and heart valve
override the SA node, producing a contraction AV node muscle disease. It is classified according to the area
pattern that is not effective in pumping blood. affected and the phase of the pumping cycle.
Slowed
AF may be treated by electrically shocking conduction In most cases fluid accumulates in the lungs
the heart back into normal rhythm. In (left-sided ventricular failure). In right-sided
ventricular fibrillation, a medical emergency, through failure (which often follows left-sided failure),
the very fast, random contractions of different damaged area fluid builds up in the feet, legs, peritoneum,
ventricular areas hinder the pumping of blood and the abdominal organs. Treatment for acute
from the heart, stopping flow to body tissues Atrial fibrillation Ventricular tachycardia heart failure includes oxygen and diuretics to
including the brain. Immediate defibrillation If the sinoatrial node is overridden by random Abnormal electrical impulses in the ventricular remove some of the edema, and medication to
is needed, with drug therapy to stabilize the electrical activity in the atria, impulses pass muscle cause the ventricles to contract rapidly, help the heart muscles contract. Chronic heart
heart. Problems such as arrhythmia occur through the atrioventricular node erratically, overriding the sinoatrial signal and resulting failure is treated with beta-blocker and ACE
when the signal does not transmit through causing fast, irregular ventricular contractions. in a fast, regular, but inefficient beat. inhibitor drugs, and by working to control the
the usual pathway. underlying cause of the problem.

454

DISEASES AND DISORDERS

HEART MURMURS murmurs may also occur in pregnancy or HEART VALVE DISORDERS atherosclerosis. Stiffness of a valve (stenosis)
conditions such as anemia, even though the makes the heart pump harder to push blood
Caused by turbulent blood flow, heart heart is normal. The sound gives a clue to the The four heart valves allow blood to flow past the obstruction, while floppiness
murmurs may signify diseased valves cause, but echocardiogram (ultrasound of the in the correct direction around the heart, (incompetence) forces the heart to do extra
or abnormal blood circulation within heart) is done to confirm the type of defect. but disease can harden or weaken them. work to pump the required volume through,
the heart. Most conditions that cause heart murmurs do as some leaks back. In both cases, the strain
not need treatment unless the underlying The valves of the heart are located between causes the heart to enlarge and become less
Unexpected sounds heard when listening to the problem causes any symptoms. Then surgery the atria (upper chambers) and ventricles efficient. This may lead to heart failure
valves closing or blood flowing through the may be done to repair any defects. (lower chambers), and at the points where (see p.453); valve disease also increases the
heart are known as heart murmurs. Common blood leaves the ventricles. Their function can risk of clots and stroke. The type of valve
causes include valve defects, such as a valve that Mitral valve be impaired by congenital defects, infections defect may be identified by ECG, X-ray, or
is too tight or floppy, or that does not close incompetence such as rheumatic fever and endocarditis, and echocardiogram. Drugs to relieve strain on the
properly. Congenital defects that produce heart can help, but if symptoms persist, surgery
abnormal blood flow include a hole in the heart Valve tightly may be needed to repair or replace the valve.
(a gap in the wall between two heart chambers) closed
and patent ductus arteriosus (the remnant of VALVE SURGERY
a vessel that carries blood in an unborn baby’s Cusp
heart but should close up just after birth). Heart There are several procedures for repairing
Normal valve or replacing a damaged heart valve. Repair
Pulmonary closed techniques include valvuloplasty or
valve stenosis The pressure outside valvotomy, used to open a stenosed valve.
the closed valve builds, A valve may be replaced with one from a
Abnormal flow and the valve cusps human donor or an animal, or an artificial
Normally, blood flows into and out of the heart snap shut so that blood valve. Another procedure is percutaneous
via one-way valves. The flow through diseased cannot flow backward. aortic valve surgery, in which a new valve
valves is disturbed, passing through at overly high is inserted inside a diseased aortic valve.
pressure, or leaking backward through the valve.
Artificial aortic valve Heart

INFECTIVE ENDOCARDITIS becomes inflamed, and infected material and Valve partially Heart valve
blood clots may collect there. Symptoms of closed Color-enhanced chest X-ray showing an
A serious infection of the endocardium endocarditis include persistent fever, fatigue, artificial heart valve. The green loops show
(the heart’s internal lining), endocarditis and breathlessness. Diagnosis is by blood tests, Abnormal cusp where the sternum (center of the chest) has
may occur after valve replacement. physical examination, and echocardiogram; an been repaired following open-heart surgery.
ECG might be done to monitor the electrical Blood leaks back
If a heart valve is diseased or has been activity of the heart. Endocarditis can be through valve
replaced, bacteria in the bloodstream can stick life-threatening and needs urgent treatment.
to its surface, causing an infection that spreads Antibiotic drugs may be given for six weeks, Incompetence
to the endocardium. The area over the valve until the infection has cleared up. If the If a valve fails to close
endocarditis persists, the valve may need to be properly, blood can flow
surgically repaired or replaced (see right). backward through it
(regurgitation), resulting
in pressure changes
within the heart.

CONGENITAL HEART vessel that should close off at birth may stay Aortic
DISEASE open, causing “shunts” of blood in the wrong narrowing
direction. Several abnormalities may be present,
Heart abnormalities that are present at as in tetralogy of Fallot (pulmonary stenosis, Reduced blood
birth affect about 8 in 1,000 babies; most ventricular septal defect, displaced aorta, and flow
of these defects are minor, but some are thickened right ventricle). Possible causes of
life-threatening. developmental problems include chromosomal Ventricular
abnormalities; illness in the mother during septal defect
The development of the heart in a fetus is pregnancy, which affects the growth of the
complex, and many types of abnormalities can baby’s heart; and the mother’s use of Septum
occur. The heart valves may not grow properly, medications, drug abuse, alcohol, or tobacco.
leading to problems such as pulmonary stenosis Ventricular septal defect Coarctation of the aorta
(narrowing of the valve that allows blood to Congenital heart disease may be diagnosed A third of congenital heart defects involve the A narrowing of the aorta (major artery from the
flow to the lungs). There may be holes in the during the pregnancy if the fetus is small for ventricular septum (the wall between the lower heart), coarctation causes abnormal circulation
chamber walls, as in septal defects (hole in the its gestational age, or after delivery, if the chambers): blood is shunted back from the left to patterns with altered blood pressure and flow,
heart), or even absent chambers. The large baby is cyanotic (blue from lack of oxygen). the right ventricle through a hole in the septum. including poor blood flow to the lower body.
vessels leading to and from the heart may be Treatment depends on the defect, the age and
abnormal in shape, size, or location, with condition of the person affected, and the
coarctation of the aorta (narrowing of part of presence of other disease. There is great
the aorta). In patent ductus arteriosus, a blood variation, from extreme defects, which need
immediate and possibly repeated surgery, to
minor valve defects, which may not become
obvious until old age.

455

CARDIOVASCULAR DISORDERS

HEART MUSCLE DISEASE the pumping action, causing abnormal beats). PERICARDITIS the membrane. Fluid may collect between the
There may be a genetic link, or some cases two layers. Symptoms include chest pain,
Many diseases can affect heart muscle, may be associated with specific factors—for Inflammation of the pericardium, the breathing difficulties, cough, fever, and fatigue.
but the cardiomyopathies are four types example, hypertrophic cardiomyopathy may twin membrane surrounding the heart, If pericarditis is suspected, ECG, chest X-ray or
of disorders. be linked to high blood pressure, and dilated can restrict the heart’s pumping action. other imaging, and blood tests may be done.
cardiomyopathy to excess alcohol use. In all
These disorders are classified by the changes forms, the changes lead to inefficient pumping Pericarditis is a response to damage, Drugs may be given to
that they produce in the heart muscle: action and heart failure, with symptoms infection, myocardial infarction, or reduce inflammation,
hypertrophic (thickening); dilated (stretching); including chest pain, breathlessness, fatigue, other inflammatory disease such as and excess fluid is
restrictive (stiffening); and arrhythmogenic (in and edema (excess fluid in tissues). Treatment rheumatoid illness. It can be acute drained. If scarring
which fatty and fibrous deposits interfere with includes drugs to reduce fluid and improve (of sudden onset), or chronic causes constriction,
heart function. Surgery may help, but the final (persistent), causing scarring of surgery may be
Right option is heart transplantation. needed to release
atrium Outer (fibrous) layer the pericardium.
of pericardium
Left atrium Blood Inner (serous)
clot Pericardial fluid layer of
Blood flow pericardium
Pericardial effusion
Right Pericardial effusion Heart
ventricle A buildup of fluid between the two layers muscle
of the pericardium can prevent the heart
Left from expanding fully.
ventricle

Septum Dilated HYPERTENSION The long-term effect on other tissues includes
ventricle damage to the eyes and the kidneys and an
Commonly defined as high blood increased risk of heart attack and stroke.
Normal heart Dilated cardiomyopathy pressure, hypertension slowly damages Causes of hypertension include a genetic
Healthy circulation depends on efficient muscle If the muscle fibres weaken, the ventricles may the heart, blood vessels, and other tendency to the condition, too much dietary
contractions pumping blood from the right side expand (dilate) and become floppy. As a result, tissues, but is usually easy to treat. salt, smoking, being overweight and inactive,
of the heart to the lungs to be oxygenated, then the heart pumps blood less forcefully, and this and drinking too much alcohol. Stress may
through the left side to the body tissues. loss of efficiency can lead to heart failure. Normal blood pressure results from the heart also be a factor. Secondary hypertension
forcing blood around the circulatory system. occurs as a result of kidney, hormonal, or
Thickened Thickened wall Rigid It varies with age, but in hypertension the metabolic disease, or as a side effect of other
septum of left ventricle ventricular blood pressure is constantly higher than the medications. Hypertension can be controlled
walls recommended level. There are rarely any by changes to diet, and by drugs that remove
symptoms, but if it is left untreated the heart excess fluid or reduce arterial wall tension, to
becomes enlarged and less efficient as a pump. reduce blood pressure. Other treatments, such
as cholesterol-lowering medication and
aspirin, are used to reduce cardiac risk.

BLOOD PRESSURE (MMHG) 180 Systolic pressure Diastolic pressure Blood pressure
160 (when heart (when heart variation
140 contracts) relaxes between Blood pressure
120 beats) normally varies
100 through the day; to
Hypertrophic cardiomyopathy Restrictive cardiomyopathy 80 Awake Asleep detect persistent high
Thickening (hypertrophy) of the muscle, often The heart muscle cannot relax properly between 60 MIDNIGHT pressure, several
around the left ventricle or septum, prevents the heartbeats, because diseased muscle fibres make 40 readings are taken.
chambers from filling as normal and causes the the ventricular walls unusually rigid and unable 20
valves to leak, so the heart’s output reduces. to fill properly or pump effectively. NOON
0
NOON

PULMONARY right side must pump harder, and over time the Arch of the aorta
HYPERTENSION ventricle thickens and heart failure develops.
Pulmonary hypertension can develop after Main pulmonary artery
Abnormally high blood pressure in the chronic heart or lung disease. There is a genetic
arteries that carry blood to the lungs is link in some families, and in others a link to Effects of pulmonary hypertension
difficult to treat and can be fatal. other disorders, but often the cause is unknown. Increased pressure in the pulmonary arteries
Symptoms include chest pain, breathlessness, causes them to thicken. In this X-ray the right
Normally, blood passes from the right side of fatigue, and dizziness. Oxygen therapy and ventricle is visibly enlarged as a result of
the heart through the pulmonary arteries at low drugs to improve blood flow can help improve working harder to pump blood to the lungs.
pressure. If the pressure becomes too high, the heart function and reduce clotting problems,
but there is no cure. Lung transplantation is an
option if medication fails.

456

DISEASES AND DISORDERS

PERIPHERAL VASCULAR DISORDERS

The peripheral vascular system includes arteries, which carry blood from the heart to all DEEP VEIN THROMBOSIS
of the body tissues, and the venous system, returning blood to the heart. Any part of
the system can be damaged by disease, which may then affect other organs and tissues. Any deep vein can develop a thrombosis
(DVT), although it usually occurs in the
ANEURYSM THROMBOSIS calf. DVT is due to static or slow-flowing
blood and clot formation. The skin over
An aneurysm is a swelling in an artery; Outer wall A thrombus, or blood clot, can form in the area is hard, painful, red, and swollen.
if it affects the aorta, the body’s main any blood vessel, causing reduced blood
artery, it can be life-threatening. Tunica media flow or blockage, or detach and travel in Risk factors include clotting diseases;
(middle layer) the circulation as an embolus. high estrogen levels, as in pregnancy or
Defects in part of the artery wall weaken the Weakened section taking the combined contraceptive pill;
area so that, under pressure from blood flow, Different types of thrombus (blood clot) may and immobility. There is a serious risk that
it stretches and may burst. Aneurysms can Fat deposit develop anywhere in the body. In veins, thrombi a broken-off piece
occur in any artery, but the aorta is more form when blood is flowing sluggishly, if the of clot (embolus)
prone to problems, and the risk of death from Common aneurysm blood is particularly thick as a result of certain could lodge in an
hemorrhage is greatest. Thoracic aneurysms Fatty deposits are a common genetic conditions, or where the inner wall of artery in the heart
occur near the heart, but aneurysms are more cause of damage to an artery a vein has been damaged and blood sticks to or lung. Treatment
common in the abdominal part. wall. The pressure of blood flow it. In arteries, thrombi usually form where a fatty includes drugs to
will stretch the weakened area plaque (atheroma) has damaged the inner wall. limit clotting and
Underlying causes include atherosclerotic until it eventually bursts. perhaps surgery to
damage (see p.452) or, more rarely, infection Thrombosis is usually symptom-free until bypass the clot.
or a genetic disorder. In many cases, aneurysms it blocks a blood vessel, when pain, redness,
produce no symptoms and are detected only and inflammation occur around the Blood clot
when they burst, or during other investigations oxygen-starved tissues. Anticoagulant drugs
or surgery. Small ones can be monitored, but if Outer wall are given to help prevent clotting. If a Leg thrombosis
they grow too large they may need surgery. thrombus is large or cannot be dissolved The usual place for
Tear in quickly, surgery to remove it is needed. a DVT is in the veins
inner wall deep within the calf.
This image shows
a clot blocking a
vein near the
shinbone (tibia).

Kidney Damage from Fibrin Thrombus
atheroma strands blocking artery
Platelets Lining

Swollen Blood in
wall of false

abdominal channel

aorta Fatty deposit

Original
channel

Abdominal aortic aneurysm Dissecting aneurysm 1 How thrombosis begins 2 Clot formation
In this angiogram (X-ray taken after radiopaque Blood is forced through a tear Atheromatous plaque forms from a collection The growing atheroma reduces blood flow
dye has been injected into the bloodstream), the in the inner wall, creating a of fatty substances, waste products, calcium, and and oxygen delivery to the tissues. The plaque
bulging aorta can be seen between the kidneys. false channel between the fibrin, a stringy substance that helps blood clot. ruptures, causing the sudden formation of a clot.
layers of the wall.

EMBOLISM during trauma or surgery, or a foreign body. remove large blood, fat, or foreign body emboli.
When an embolus blocks an artery, the tissue Often the embolus is small, but treatment such
The sudden blockage of an artery by an supplied by that artery dies. In pulmonary as anticoagulant drugs to prevent blood clots
embolus (a plug of free-floating matter), embolism (see p.451), damage to lung tissue is given to prevent further emboli occurring
embolism is serious and can be fatal. results in breathing difficulties, chest pain, and from the same source.
circulatory collapse. Emboli (most commonly
Many emboli are “thromboemboli”—pieces thromboemboli) that travel up to the brain can Embolus blocking
broken off from a blood clot (thrombus) inside cause a stroke. Fat emboli may affect lung, brain, blood flow
a blood vessel. Emboli can also form if fat enters or skin tissues, while air emboli can be fatal.
the blood, usually after a fractured pelvis or A suspected embolus requires hospital Subclavian artery
tibia. Other types include an air embolus, in admission while the type and location of the
which air is introduced into the bloodstream embolus is determined. Thrombolysis Embolus blocking an artery
(clot-busting) medication is used to dissolve The most common emboli are thromboemboli:
thromboemboli; surgery may be needed to pieces from a clot that travel in the bloodstream
until they lodge in a smaller artery, as shown here.

457

PERIPHERAL VASCULAR DISORDERS

LOWER LIMB ISCHEMIA RAYNAUD’S DISEASE (SLE), scleroderma, or multiple sclerosis cause VASCULITIS
secondary Raynaud’s, or develop after Raynaud’s
The lower legs are more prone than other The main feature of this condition is symptoms occur. “Hand–arm vibration Inflammation of the blood vessels, or
areas to ischemia—oxygen starvation of Raynaud’s phenomenon—constriction of syndrome” in workers who use vibrating tools vasculitis, is an uncommon condition but
the tissues—if the blood flow is reduced. the tiny blood vessels in the extremities. is another cause. In both Raynaud’s disease it can affect any organ or body system.
and secondary Raynaud’s, attacks may be
Lower limb ischemia may occur when blood In Raynaud’s phenomenon, the fingers, toes, triggered by cold or stress. In half of all cases, the cause is unknown, but
flow in an artery is reduced due to a thrombus ears, or nose whiten and cool as the vessels in the remaining cases the condition results
(clot) or atheroma (fatty deposit), embolism, or constrict, before turning blue, purple, or black Symptoms can be avoided by keeping from infection, another inflammatory disease
constriction from an injury or local pressure. If as blood oxygen levels fall. Vessels then dilate the extremities warm, with thermal underwear such as rheumatoid arthritis (RA), cancer, some
ischemia is acute (sudden), as when a large again and blood flow increases, turning the and heated gloves and socks, and not medications, drug use, or contact with
thrombus blocks a major artery, the result is a tissues red, with pain and throbbing. There smoking or using drugs that cause blood vessel chemical irritants. Symptoms depend on the
cold, painful, blue, pulseless leg, which needs may also be joint pain, swelling, constriction. Medication to improve blood size and location of affected blood vessels. The
emergency treatment to prevent shock and rashes, and muscle weakness. flow may be given. Causes of secondary most common problems are skin lesions,
gangrene. Any clot needs to be dissolved by Generally the cause is unknown, Raynaud’s need to be controlled. rashes, and ulcers. Internally there may also be
drugs or surgically removed to restore the in which case the condition is bleeding and swelling or blockage of vessels or
circulation; if the tissue dies, the only option is defined as Raynaud’s disease. In organs. Blood tests for inflammation and
amputation. some people, diseases such as autoimmune diseases, X-rays, and other tests
rheumatoid arthritis (RA), may suggest vasculitis, but it can be confirmed
Chronic (long-term) ischemia may cause systemic lupus erythematosus only by tissue biopsy.
intermittent claudication (cramplike pains
during exercise), when the muscles do not Raynaud’s phenomenon Treatment depends on the underlying cause:
receive enough oxygen through the narrowed As arteries constrict and blood flow for example, avoiding any causative medications
arteries. In these cases atherosclerosis may have reduces, the extremities turn pale and treating infection. Further treatment
partially blocked the arteries, and blood-thinning and cool. When the vessels dilate depends on the organs affected and the overall
medication will help blood flow, or angioplasty, again, pain, numbness, and health of the person. In rare cases, surgery is
stenting, or bypass will dilate the artery again. throbbing are common. needed to repair damaged large vessels.

VENOUS ULCERS to leak out of the veins into the surrounding the leg to help blood return to the heart and
tissues. The tissues and the skin above them reduce fluid pressure in the tissues, and
Usually developing on the lower leg or swell, and the skin surface eventually breaks elevation of the leg, again to improve blood
ankle, venous ulcers are persistent, often down to form an ulcer. The raw, open tissue return. If the ulcer fails to heal, surgery to the
painful open sores that are particularly may be painful and can become secondarily vein or the use of skin grafts to cover the ulcer
common in older people. infected. Without treatment, large areas of skin may provide a more permanent solution.
necrose and die, leaving exposed fat or muscle.
If the walls of the veins become weakened, the Venous ulcers can be identified by their Venous ulcer
circulation will fail to return blood effectively appearance. To assess circulation, the doctor
to the heart. As a result, pressure builds up in will compare the blood pressure in the ankle Ulceration
the veins. This increased pressure causes fluid to that in the arm, because poor circulation Poor blood circulation can result in chronic tissue
gives a lower ankle pressure. Treatment damage and ulcer formation. Appearing as shallow
includes compression bandages applied to craters in the skin that expose the underlying tissue,
ulcers can be difficult to heal.

VARICOSE VEINS overstretched by normal blood pressure. examination, but specialized ultrasound
Varicose veins may cause no symptoms, or scanning may also be used to investigate
Typically visible as lumpy swellings on may result in aching, heaviness, itching, and blood flow, especially if there are
the legs, varicose veins can run in families swelling. Diagnosis is usually made by clinical complications or the problem is recurrent.
and are more common in women.
TREATING VARICOSE VEINS Sclerotherapy
Normally, muscle contractions in the legs help During sclerotherapy treatment, veins are
to push blood through veins back to the heart, Mild varicose veins may need no other injected with a chemical to seal them. They
and one-way valves in the veins prevent blood treatment apart from surgical stockings to can be highlighted using ultrasound and
from flowing backwards. Varicose veins occur support the vein walls and measures to marked on the skin, as shown here.
mainly in the legs when the valves fail to close prevent them from worsening, such as
Varicose veins in the leg properly, causing backflow to occur and exercise, weight loss, and avoiding standing
Any vein can become varicose, but the most pressure to increase in the veins, making the for long periods. However, varicose veins
common site is the lower leg, where the swollen, veins swell. Varicose veins are often caused by can be made worse by ulcers, eczema, and
distorted veins may become more prominent if increased pressure from abdominal swelling in swelling of the ankle. Surgery offers some
the affected person stands for a long time. pregnancy or obesity, or by pressure in the improvement, although the problem may
lower legs due to prolonged standing. In rare recur. Techniques such as sclerotherapy,
cases, the vein walls are abnormally elastic or radiofrequency, and laser techniques can
some valves are missing, so the veins are be used to seal the veins, depending on
their severity and location.

458

DISEASES AND DISORDERS

BLOOD DISORDERS

Abnormal numbers and forms of red blood cells, white blood cells, and platelets can occur due to a variety
of disorders, including anemia and leukemia. Abnormalities in blood clotting mechanisms result in blood
that clots either too readily, leading to thrombosis, or not enough, leading to bleeding and bruising.

ANEMIA classified by the size of the red blood cells. In microcytic anemia they
are smaller than normal, in macrocytic anemia they are bigger, and
In anemia, there is a reduction in the number of red blood cells or in in normocytic they are normal-sized. Abnormalities in the hemoglobin
the concentration of hemoglobin—the pigment in red blood cells that molecules can cause further variations of the condition.
transports oxygen around the body. As a result, anemia can lead to
hypoxia (oxygen deprivation) in cells. Different types of anemia are

THALASSEMIA MICROCYTIC AND depends on finding the underlying cause but APLASTIC ANEMIA
MACROCYTIC ANEMIA includes iron replacement. Macrocytic anemia
Genetic defects can cause the formation (where the red blood cells are bigger than In this condition the bone marrow fails
of abnormal hemoglobin molecules Microcytic anemia is often caused by normal) may be caused by hypothyroidism (see to produce sufficient blood cells and
leading to anemia. Beta thalassemia iron deficiency in the diet. The rarer p.482) or alcoholism. A deficiency of vitamin platelets to sustain normal function.
is the most prevalent of these disorders. macrocytic anemia is usually due to B12 or folic acid causes a type of macrocytic
a deficiency of vitamin B12 or folic acid. anemia called megaloblastic anemia. Dietary The cause of aplastic anemia is often unknown,
Beta thalassemia major is an inherited disorder supplements usually help treat this condition. or it may be due to toxins, radiation, and certain
and is common in the Mediterranean region If blood is lost and not replaced by iron in the drugs. Lack of platelets in the blood leads to
and southeast Asia. A fault in the production of diet, iron deficiency and microcytic anemia may Pernicious anemia is another type of bruising and excessive bleeding. Low levels of
hemoglobin leads to red cells that are rigid, develop. In this condition the red blood cells macrocytic anemia and is caused by a lack white cells lead to unusual and life-threatening
fragile, and easily destroyed. This leads to severe are smaller than normal. Causes of bleeding of intrinsic factor, produced in the stomach and infections. Reduction in red blood cells leads
anemia by the age of 6 months and also to include menstration, parasitic infection, gastritis, required to absorb B12 from food. It can be to anemia, causing
retardation of growth. As the bone marrow peptic ulcers, and colon cancer. Treatment treated with vitamin B12 injections. Normocytic paleness, fatigue, and
expands to produce more red blood cells, the anemia, in which red blood cells are normal- shortness of breath.
long bones become thin and liable to fracture, sized but hemoglobin levels are low, occurs in Diagnosis is by bone
and the skull and facial bones become distorted. aplastic anemia (see right), chronic diseases, marrow biopsy.
The liver and spleen enlarge as they try to and disorders with increased destruction or Treatment is by bone
produce red blood cells as well. loss of red blood cells. Symptoms of anemia marrow transplant.
include fatigue, shortness of breath on exertion,
Diagnosis can be made from blood tests pallor, and pale nail beds. Treatment depends Red blood cell
that show hemoglobin levels. Frequent blood on the cause.
transfusions with iron chelating treatment Bone marrow smear
(which prevents iron overload) help correct the Misshapen red blood cell Fewer red and white
anemia. Bone marrow transplant is the only blood cells than is
cure and may be offered for severe cases. Severe microcytic anemia usual are shown in this
This blood smear shows red blood cells that bone marrow sample.
are smaller and paler than normal, and some
misshapen red blood cells. This is characteristic
of microcytic anemia.

SICKLE CELL ANEMIA crises) and eventual organ damage. A crisis can of hydroxyurea; crises are treated with
be triggered by infection and dehydration; the rehydration, strong analgesics, antibiotics, and
A mutation in the hemoglobin gene leads severity, frequency, and duration varies. transfusions. Bone marrow transplant may be
to red blood cells of a fragile, rigid sickle offered in severe cases.
shape that do not pass easily through Typical symptoms include painful bones
small blood vessels. and joints, severe abdominal pain,
chest pains, shortness of breath,
and fever. Treatment is aimed at
prevention through long-term use

Chest X-ray of person with thalassemia In sickle cell anemia, the red blood cells Sickle-shaped cell
This color-enhanced chest X-ray shows a contain an abnormal type of hemoglobin. It is
deformed ribcage as a result of marrow diagnosed by blood tests, and is usually first Deformed red blood cell
expansion. The bones become distorted as the detected at the age of 4 months. The abnormal Abnormal sickle cells are fragile, have
body tries to produce more red blood cells. sickle cells restrict blood flow to organs, difficulty passing through the blood
leading to episodes of severe pain (sickle cell vessels, and have a reduced lifespan,
leading to long-term anemia.

459

BLOOD DISORDERS

LEUKEMIA BONE MARROW TREATMENT

Cancer of the bone marrow and white Stem cells in the Blood cell production Normal bone marrow may be transplanted
blood cells leads to bone marrow failure, bone marrow All blood cells derive into people needing treatment to replace
causing immunosuppression, anemia, from stem cells found in cancerous or defective marrow. This is
and low platelet counts. the bone marrow. Red done for life-threatening conditions such
blood cells carry oxygen. as leukemia or aplastic anemia. First
In acute leukemia, immature, malignant white Red blood cell Platelet Lymphocytes are a type of the diseased bone marrow is destroyed
blood cells rapidly proliferate and reduce the Lymphocyte white blood cell that fights through radiation, then healthy bone
numbers of normal blood cells. They then spill infection. Platelets help the marrow cells are transfused into the
over into the blood, spreading to other organs Lymphoblasts blood clot at injury sites, patient’s circulation. Cells are harvested
in the body. Lack of platelets leads to bruising, circulating in reducing blood loss. (removed) from a large bone such as the
excessive bleeding, and petechiae (red bloodstream pelvis. A donor must have the same tissue
or purple spots on the body caused by Lymphoblasts type as the patient and so is usually a close
hemorrhage). Poorly functioning white multiply relative or even the patient himself. Bone
cells are unable to fight infection, leading marrow transplants are also done using
to a greater risk of unusual and life-threatening stem cells taken from a donor or from
infections. Lack of red blood cells leads to umbilical cord blood.
anemia. Leukemia is diagnosed by blood tests
and bone marrow biopsy. Fewer Fewer red Acute lymphoblastic
platelets blood cells leukemia (ALL)
Acute leukemia is fatal without treatment, Lymphoblasts (immature
including chemotherapy and bone marrow or malignant lymphocytes) Bone marrow
stem cell transplant. In children, the prognosis rapidly proliferate in the Microscopic view of healthy bone marrow
with treatment is excellent. In chronic leukemia, bone marrow. As a result, that can be harvested and used to replaced
mature malignant white blood cells proliferate the production of normal diseased bone marrow.
slowly over months to years, so bone marrow blood cells is disrupted.
function is maintained for longer. The cells Lymphoblasts also spread
spread to the liver, spleen, and lymph nodes, to the bloodstream and
causing them to enlarge. Chronic leukemia carry the cancer to other
mainly affects older people and may be treated organs and tissues in
by chemotherapy or bone marrow transplant. the body.

LYMPHOMAS lymph nodes in the neck, armpits, or groin, and Lymphoma lymph cells PLATELET DISORDERS
fever, weight loss, night sweats, and fatigue. The stage of the lymphoma can be found by
Lymphomas are cancers that develop Hodgkin’s lymphoma is a rarer type that affects checking whether the cells are confined to one Platelets aid the clotting of blood.
when the lymphocytes (white blood cells) either adults aged 15 to 35, or people over 50, group of nodes or have spread beyond the Excessive numbers of platelets leads
of the immune system form solid tumours and runs a very aggressive course. It is easily lymphatic system to the liver, skin, and lungs. to clots in the blood (thrombosis).
in the lymphatic system. curable in young people, slightly less so in older A deficiency causes excessive bleeding.
adults. The other lymphomas mainly occur in
There are more than 40 different types of people over 60 and may run an aggressive or Reduced platelet count (thrombocytopenia)
lymphoma, classified according to cell type. indolent (slow) course. may be due to disorders such as aplastic
The major categories are mature B cell anemia (see opposite) and leukemia or result
neoplasms, mature T cell neoplasms, natural Diagnosis is based on taking a biopsy (tissue from increased destruction of platelets due to
killer cell neoplasms, and Hodgkin’s sample) from a lymph node and checking for conditions including SLE (lupus) and idiopathic
lymphoma. All types may cause swelling of the spread by scanning. Treatment includes thrombocytopenic purpura (low platelet count
chemotherapy, radiotherapy, monoclonal with no known cause). Certain drugs (such as
antibody therapy, and corticosteroids. Early those used in chemotherapy, and interferon)
treatment gives a better outlook. that suppress the bone marrow also cause a
reduced platelet count. This leads to bruising,
CLOTTING DISORDERS Bruising caused by hemophilia bleeding into internal tissues such as the excessive bleeding, and red or purple spots
Extensive bruising occurs after even minor trauma muscles and joints, causing severe pain on the body (petechiae).
Failure of the blood to clot sufficiently in severe hemophilia. Spontaneous bleeding and joint destruction.
may be genetic, autoimmune, or typically causes nosebleeds and bleeding gums. Platelet disorders are diagnosed by blood
acquired for other reasons and can lead Hemophilia is treated by regular infusions of counts or bone marrow biopsy. Platelet count
to excessive bruising and bleeding. the deficient clotting factor. Von Willebrand’s may be raised following inflammation, surgery,
disease is a common inherited disorder that bleeding, and iron deficiency, or unknown
Hemophilia A is a rare inherited disorder that usually has no symptoms, but can lead to easy reasons. This does not usually need treatment.
causes a deficiency in a blood protein, factor bruising, nosebleeds, and bleeding gums; it High platelet count causes no symptoms but
VIII, that is essential for clotting. This leads usually requires no treatment. Other clotting increases the risk of thrombosis (clotting).
to prolonged bleeding and rebleeding after disorders may be caused by liver failure, Aspirin may be given to reduce this risk.
trauma or even spontaneously. There may be leukemia, or vitamin K deficiency. Tests may be Idiopathic thrombocytopenic purpura may
done to see how long the blood takes to clot. require corticosteroids and specialist drugs.
Treatment may be given to keep clotting factors
in the blood high enough to prevent bleeding.

460

DISEASES AND DISORDERS

ALLERGIES AND AUTOIMMUNE DISORDERS

The basis of an allergy is an inappropriate reaction by the immune system in response
to certain substances. In autoimmune disorders, the body’s immune system reacts
against its own cells and tissues, causing a variety of diseases.

ALLERGIC RHINITIS animal saliva and skin flakes (dander). Sneezing, ANAPHYLAXIS ANGIOEDEMA
a runny nose, and sometimes runny, itchy eyes
Contact with an airborne allergen and itchy throat occur within minutes of A massive immune response to an Angioedema is the local onset of swelling
provokes an immune response in the exposure; the nose becomes blocked a few allergen leads to anaphylaxis, a below the surface of the skin, due to the
lining of the nose, causing swelling, hours later. Allergy testing includes skin prick potentially fatal multisystem reaction, leakage of fluid from blood vessels. This
itching, and excessive mucus production. testing and blood testing. In hay fever, the time within minutes to hours of the exposure. is usually caused by an allergic reaction.
of the year may indicate which type of pollen is
In seasonal allergic rhinitis (hay fever), symptoms involved. Allergic rhinitis can be prevented or Anaphylaxis is a severe, potentially fatal allergic Angioedema usually affects the face and mouth
occur when certain pollens are in the air. reduced by avoiding triggers and using oral reaction caused by exposure to an allergen and the mucosa (lining) of the mouth, tongue,
Hayfever is rare before the age of 6 years, usually antihistamines, intranasal corticosteroids, and, if (typically nuts, drugs, or insect stings). The and throat, but possibly other areas as well,
develops before the age of 30, and affects up to the eyes are affected, cromolyn eyedrops. allergen may be ingested, injected, touched, or leading to swelling. This can interfere with
1 in 5 people. Hay fever is often associated with Immunotherapy and desensitization may be inhaled. The initial sense of anxiety, with breathing, and the airway may have to be kept
eczema (see p.422) and asthma (see p.450). used for severe, chronic cases. itching and flushing, is quickly followed by open with a tube. Common allergic triggers are
Perennial rhinitis can occur throughout the year problems that include a catastrophic fall in peanuts, seafood, and insect bites. Drugs may
and is commonly caused by house dust mites or blood pressure (anaphylactic shock). This leads induce nonallergenic angioedema. It is most
to fainting and unconsciousness, wheezing, commonly treated with antihistamines. Known
Dust mites constriction of the airways, shortness of breath, trigger factors need to be avoided, and in
Millions of dust mites are present in bedding and and respiratory failure. There may also be chest severe cases the cause of the reaction may be
carpets in the home. Their feces can provoke pain and palpitations, nausea and vomiting, gradually introduced, to build up tolerance.
allergic reactions in many people. diarrhea, angioedema (see right) and skin
problems including urticaria (see p.423). Swollen lower lip
Pollen grain In angioedema, swelling occurs beneath the skin
Grass pollen is a common Anaphylaxis comes on suddenly and around the mouth, rather than on the skin
cause of hay fever. The pollen progresses rapidly. It is a life-threatening surface. It may continue for hours or even days.
count is highest from spring emergency because the airways and circulation
to early summer. may become severely impaired within minutes.
Affected people should carry epinephrine “pens”
for emergency; treatment includes resuscitation
and immediate administration of epinephrine
to open the airways, stimulate the heart, and
constrict the blood vessels. Prevention involves
avoiding the cause of the reaction and building
up tolerance to the allergen.

FOOD ALLERGIES allergy is different from a food intolerance in SKIN TESTING FOR ALLERGIES
which symptoms arise from food toxins (for
An adverse immune response to a food example, bacterial food poisoning), problems In a skin prick test, a drop of fluid containing
protein leads to a variety of problems with digestive enzymes (such as lactose a potential allergen is applied to the skin,
including anaphylactic shock and eczema. intolerance), or the direct action of chemicals which is pierced with a needle or scratched.
in the food (such as caffeine causing tremors). A positive reaction (itching, redness, and
Food allergies affect around 6 percent of swelling) indicates that the person may be
children but are slightly less common in adults. People with a suspected food allergy may allergic to that substance. In patch testing,
The most common triggers are dairy products, be offered blood and skin testing (see right) used to test for allergic contact dermatitis,
egg, nuts, seafood, shellfish, soy, wheat, and to find the cause of the problem. Food diaries the allergen is applied directly onto the skin,
sesame products. A food allergy may cause a and dietary exclusion may also help identify covered with adhesive tape, and a reaction
range of symptoms from itching and rash to the allergen. If this is unsuccessful, the suspected is checked for a few days later.
nausea, abdominal cramps, and diarrhea. It allergen may be given under hospital supervision
may also cause wheezing and difficulty to provoke the reaction. People with allergies Skin prick testing
swallowing, brought on by swelling of the are advised to avoid foods that trigger the A skin prick test is done to diagnose common
airways and angioedema (see right). A food condition. Antihistamines may be used to treat allergies to pollen, dust, dander (animal skin
mild allergies. People with severe allergies may flakes), saliva (such as cat’s saliva), and foods.
need to carry an autoinjector of epinephrine
(adrenaline) for emergency treatment.

461

ALLERGIES AND AUTOIMMUNE DISORDERS

SYSTEMIC LUPUS Pale skin with red Inflamed membranes POLYMYOSITIS AND
ERYTHEMATOSUS “butterfly” rash across nose around the lungs (pleura) DERMATOMYOSITIS
causing chest pain and
and cheeks; hair loss shortness of breath

Commonly called lupus, this condition is Painless ulcers in mouth Inflammation of the In these two rare related autoimmune
an autoimmune disorder of the tissue or occasionally nose membrane around the disorders, the muscle fibers become
that provides the structure for the skin, heart (pericardium), inflamed. In dermatomyositis, the skin
joints, and internal organs. causing chest pain is also affected.

Systemic lupus erythmatosus (lupus), affects Inflammation of blood Nervous system Polymyositis and dermatomyositis are more
2–10 people per 10,000 and can run in vessels, restricting is affected, causing common in women than in men, and tend to
families. It is more common in women and blood circulation headaches, blurred develop in middle age, but dermatomyositis
develops from the teenage years onward. It vision, and strokes can occur in children. In both conditions, the
is caused by the immune system’s antibodies Inflammation of filtering arm and leg muscles weaken, typically making
reacting against connective tissue in the body. units in the kidneys, Painful, swollen, it hard to get up from a chair or lift the arms
This causes the tissues to become inflamed. and stiff joints over the head. Other symptoms of polymyositis
leading to kidney failure include fatigue, fevers, and weight loss. If the
Lupus may be triggered by infections, Constriction of esophagus is affected, difficulty swallowing also
puberty, menopause, stress, sunlight, and Symptoms and signs of lupus blood vessels in occurs. Weakness of the chest wall muscles
certain drugs. The symptoms vary widely Lupus most often affects the skin, the fingertips and diaphragm can lead to difficulty breathing.
in severity, and come and go. Flare-ups may heart, joints, lungs, blood vessels,
last for weeks then disappear for months or liver, kidneys, and the central nervous Muscle fatigue and pain Dermatomyositis also causes skin changes
even years. The progression of the disease system. It may involve only a few of including a red scaly rash on the knuckles, knees,
ranges from very slow to rapid. The most these areas or be widespread. and elbows; rough and cracked skin on the
common symptoms are fatigue, joint pain, fingertips; swelling and violet discoloration
fever, and weight loss. Up to half of people with around the eyes; and flat, reddish areas on
lupus develop the classic “butterfly” rash across the face, neck, and chest. These skin changes
the nose and cheeks. Lupus is diagnosed in may appear before any muscle problems
part by testing the blood for certain antibodies. occur. Diagnosis is by the presence of certain
There is no cure, but immunosuppressive antibodies in the blood, electrical testing of
agents, including corticosteroids, can be given muscle and nerves, and muscle biopsy (taking a
to control symptoms, and to help prevent sample of tissue). Treatment includes the use of
flare-ups and reduce their severity. immunosuppressives, including corticosteroids.

POLYARTERITIS NODOSA ulcerate, die, or atrophy (wither away). The SCLERODERMA Lump of calcium
inflamed arteries may dilate and rupture, leading
This autoimmune disorder causes to nodules, mottling, ulcers, and gangrene. In this rare disorders, antibodies damage X-ray of hand affected by scleroderma
inflammation of the walls of small or People with polyarteritis may feel generally smaller blood vessels and cause Lumps of calcium can form under the skin on
medium-sized arteries (blood vessels), unwell, lose weight, and have fever and loss hardening of the connective tissue fingers or other areas of the body (calcinosis) in
which restricts blood supply to tissues. of appetite. Polyarteritis can lead to kidney throughout the body. scleroderma. They may require surgical removal.
failure (see p.469), hypertension (see p.455), slow or reverse progression but there is no
A rare autoimmune disorder that mainly and heart attack (see p.453). Scleroderma runs in families, is more common cure. Other treatments can be given to relieve
occurs in people aged 40–60 years, in women, and typically begins between the symptoms. Regular monitoring of the condition
polyarteritis nodosa affects the arteries Digestive problems caused by the ages of 30 and 50. With morphea (limited is necessary as further complications may arise.
supplying the heart, kidneys, skin, liver, condition include bleeding and perforation of cutaneous scleroderma), it is mainly the skin
digestive tract, pancreas, testes, skeletal the intestine. In men, the testes may inflame that is affected. With diffuse cutaneous
muscles, and central nervous system. Areas of (orchitis). Musculoskeletal involvement causes scleroderma (systemic scleroderma), large
the body supplied by inflamed arteries may muscle pain and arthritis. Diagnosis is based areas of skin and the internal organs are
on a tissue biopsy of an affected artery or affected, and the condition rapidly progresses.
organ. Immunosuppressive agents such as The skin becomes swollen and then thickened,
corticosteroids are used to treat the condition. shiny, and tightened, making it hard to move
the joints, especially in the hands. Many
Weakened people with scleroderma develop Raynaud’s
artery wall disease (see p.457). Hardening of the
connective tissues elsewhere may affect the
Artery affected by lungs, heart, kidneys, and digestive tract.
arteritis Swallowing problems and gastric reflux are
common due to the esophageal muscles
Shown in cross becoming stiffened.
section, the wall of the
artery shows marked Diagnosis is based on a skin biopsy (tissue
inflammation, is sample) and, in part, checking for the presence
weakened and may of antibodies (that attack the body’s own tissue)
eventually rupture. in the blood. Immunosuppressive drugs may

462

DISEASES AND DISORDERS

UPPER DIGESTIVE TRACT DISORDERS

The common disorders of the mouth, esophagus, stomach, and duodenum are often ENDOSCOPY
caused by irritation leading to inflammation and problems such as ulcers. Some of these
disorders are related to infection with bacteria, such as Helicobacter pylori in the stomach. An endoscope is a thin, flexible or rigid
tube containing optical fibers, through
GINGIVITIS MOUTH ULCERS which light passes to illuminate internal
body structures and relay images back to
Inflammation of the gums (gingivitis) is A break in the mucous membrane of the Ulcer inside lip an eyepiece or monitor. Within the shaft,
caused by a buildup of dental plaque, mouth leads to a painful open sore, or A minor aphthous ulcer is a small, painful, white, there are also channels down which
usually resulting from poor oral hygiene. ulcer. Aphthous ulcers are the most grey, or yellow area, forming an oval-shaped pit, instruments or manipulators may be
common type of mouth ulcer. with an inflamed red border. passed to cut out pieces of tissue (biopsy),
Plaque is a film of bacteria that collects where grasp objects, and allow treatments using
the teeth meet the gums. The bacteria inflame Aphthous ulcers or canker sores are painful more painful, take many weeks to heal, and laser and electrocautery devices. Irrigating
the gums, causing them to become reddish open sores inside the mouth. Minor ulcers are may scar. Treatments include using a saltwater fluids and gases can flow down other
purple and tender and to bleed easily after usually due to injury from vigorous brushing, mouthwash, steroid pastes or lozenges, and channels. Different types of endoscope
brushing. If gingivitis is left untreated, deep biting the inside of the cheeks, sharp teeth, anesthetic gels. Ulcers persisting for longer than are used for particular body areas, such
pockets may form between the teeth and gums, braces, and dentures. The ulcer typically forms 3 weeks require investigation. as a colonoscope for the large intestine or
and the tissues supporting teeth can become a small, pale pit, and the area around it may a gastroscope for the stomach. In most
inflamed (periodontitis), causing the teeth to fall become swollen. Minor ulcers clear up within upper digestive tract disorders, endoscopy
out. Smoking and alcohol increase the risk of 2 weeks. Recurrent minor mouth ulcers affect is replacing barium studies (swallowing a
gingivitis, but regular brushing, flossing, and around 1 in 5 people, often appearing in white fluid that shows up on X-rays) as the
dental checkups help prevent it. Removal of groups of four to six. Major aphthous ulcers are preferred form of investigation.
any plaque that develops is important. larger (more than 0.5 in / 1 cm wide), deeper,

CANCER OF THE SALIVARY GLAND STONES infection of the gland, dehydration, poor saliva Endoscopic view of stomach
ESOPHAGUS flow, and injury to salivary ducts. The stone The gastric mucosa (inner lining) of a healthy
Hard masses formed from calcium causes a painful swelling that may worsen stomach as seen through an endoscope.
Malignant tumors of the esophagus are phosphate, calcium carbonate, and other during meals, when salivary flow increases. This procedure may be carried out to
often linked with smoking and excess minerals can develop in the salivary It is diagnosed by seeing or feeling a lump in investigate upper digestive tract disorders.
alcohol use, and have a poor prognosis. glands, leading to painful swelling. the gland and by imaging the stone on X-ray,
ultrasound, or CT scans. Some stones can be Esophagitis
Most common in males over 60, this form Salivary gland stones, also called sialoliths, may removed by just massaging them out of the An endoscopic view of the esophagus, showing
of cancer usually causes difficulty swallowing be single or multiple. They most commonly salivary duct; otherwise, surgery is required. ulceration and inflammation due to reflux. Over
solids, and then soft foods, and finally fluids. form in the submandibular glands, in the Obstruction of the duct by a stone can cause time, inflammation may cause narrowing of the
It commonly leads to substantial weight loss; lower jaw, and may be associated with chronic a bacterial infection of the salivary gland esophagus (stricture) or cancerous changes.
other symptoms include regurgitation of food, (sialoadenitis), which is treated with intravenous
coughing, hoarseness, and vomiting blood. It GASTRIC REFLUX antibiotics and sometimes surgical drainage. Ulcerated tissue Inflamed lining
is diagnosed by barium studies or endoscopy
with biopsy, but the cancer has often spread by The backflow of acidic stomach contents stomach contents, it leads to heartburn, a
this time. The tumor will need to be removed, up into the esophagus causes the painful burning sensation behind the breastbone.
and a tube (stent) may be inserted to keep the sensation known as heartburn. Common causes of heartburn are overeating,
esophagus open and allow swallowing. eating fatty foods, excess coffee or alcohol
The lower esophagus passes through a hole in intake, smoking, obesity, and pregnancy.
Tumor in the the diaphragm before it joins the stomach at If the reflux is persistent or severe, it may
esophagus the gastroesophageal junction. The hole is cause the esophagus to become inflamed,
This colored normally taut, together with the esophageal leading to ulceration and bleeding. Over
barium study sphincter, a ring of muscle at the base of the time, esophagitis may cause narrowing of
shows the large, esophagus, helps prevent acidic stomach the esophagus or cancerous changes. The
irregular outline of contents from flowing up into the esophagus condition is diagnosed by endoscopy and can
a tumor protruding (gastroesophageal reflux). If this structure is usually be relieved by lifestyle changes. For
into the interior of weakened and unable to stop the reflux of reflux, drugs may be given to reduce acid
the esophagus. production in the stomach, tighten the
esophageal sphincter, or neutralize the
Tumor stomach acid. Keyhole surgery can be done
to tighten the esophageal sphincter.

463

UPPER DIGESTIVE TRACT DISORDERS

Mucosa PEPTIC ULCER (black, tarry stools). Severe ulcers may perforate
the stomach or duodenum wall; this is a surgical
Submucosa An erosion in the lining (mucosa) of the emergency. Ulcers are detected by endoscopy,
stomach or first part of the duodenum, a and H. pylori infection is confirmed by biopsy
Muscle peptic ulcer can cause pain and bleeding. and blood or breath tests. Drugs are given to
layer reduce stomach acid production so the ulcer
The cells lining the stomach and duodenum can heal, and to eradicate H. pylori infection.
Shallow areas of secrete a layer of mucus that protects them
damage occur, but from damage by stomach acid. If this layer is Esophagus Fundus
breached, an ulcer can form. Most peptic ulcers
the submucosa are caused by persistent inflammation due to Lesser curvature
remains unbreached the bacterium Helicobacter pylori. The other
Early ulcer major cause is the use of aspirin or nonsteroidal Duodenal
If the mucus layer protecting the stomach anti-inflammatory drugs (NSAIDs) or ibuprofen, bulb
lining is breached, stomach acid can attack which reduce the secretion of mucus. Further
and damage mucosal cells. contributory factors include smoking, alcohol, Body
family history, and diet.
If the ulcer erodes The ulcer eats Antrum
a large blood vessel, into the Symptoms include upper abdominal pain,
submucosa often related to eating; bloating; and nausea. Pylorus
bleeding may Ulcers last for days to weeks and may recur
be severe every few months. Bleeding ulcers can cause Sites of peptic ulcer
hematemesis (vomiting of blood) or melena The most common site is the duodenal bulb, the
Progressive ulceration first part of the duodenum, where the stomach
The ulcer erodes the deeper layers. It empties into the duodenum. In the stomach,
may even perforate (break through) the most ulcers develop in the lesser curvature.
wall of the stomach or duodenum.

GASTRITIS vomiting (sometimes with blood), and bloating. HIATUS HERNIA severe symptoms or long-term reflux may have
Chronic (long-term) gastritis is usually due to surgery to repair the hernia. During surgery, the
Inflammation of the stomach lining may infection of the stomach lining by the bacterium A tear or weakness in the diaphragm (the upper part of the stomach is wrapped around
be acute or chronic and has a variety of Helicobacter pylori, which weakens the protective large, flat muscle that separates the chest the lower part of the esophagus, stopping the
causes, often related to irritation or mucus barrier. Gastritis is diagnosed by and abdominal cavities) can allow part of stomach from protruding through the hiatus.
infection of the lining. endoscopy. Treatment includes addressing the the stomach to protrude into the chest.
underlying cause and using drugs to neutralize Hernia (pouch
stomach acid or reduce acid production. of stomach)

The stomach lining normally protects itself Bacterium Stomach In the most common “sliding” form of hiatus
from the acidic stomach contents by a layer of hernia, the junction between the esophagus
mucus, but if this barrier is disrupted, gastritis and the stomach slides upward through Esophagus
(inflammation) can occur. Acute (sudden, the diaphragm. This form is very common, Diaphragm
onset) gastritis is usually caused by excessive especially in people over 50. It usually causes
alcohol intake, which irritates the stomach lining, no symptoms, but a large hernia may result in Stomach
or by the use of aspirin or nonsteroidal anti- gastroesophageal reflux. Measures to relieve Paraesophageal hiatus hernia
inflammatory drugs (NSAIDs) such as ibuprofen this problem include raising the head of the A pouchlike part of the upper stomach is
or naproxen, which reduce the production of bed, avoiding lying down after meals, losing pushed upward through the hole (hiatus) in the
mucus by the stomach lining cells. Symptoms weight, and using medications to reduce diaphragm where the esophagus normally passes
can include pain in the upper abdomen, nausea, acid production in the stomach and tighten through to join the stomach.
the esophageal sphincter. In the much rarer
Bacteria in the stomach paraesophageal hernia, the top of the stomach
More than 50 percent of people carry H. pylori. may become constricted in the chest and have
It causes long-term, low-level inflammation of its blood supply cut off. This needs urgent
the stomach lining and can lead to peptic ulcers, surgical treatment. A hiatus hernia is diagnosed
chronic gastritis, and stomach cancer. by endoscopy or barium study. People with

STOMACH CANCER salted, smoked, or pickled food (as in Japan); of the stomach may require removal of the
disorders such as pernicious anemia; and esophagus as well (esophagogastrectomy).
A malignant tumor of the stomach is a previous stomach surgery. Symptoms include Typically, stomach cancer has already spread
common form of cancer worldwide but is loss of appetite, unexplained weight loss, by the time it is detected, so radiation therapy
uncommon in the US. nausea, vomiting, bloating, and feeling “full and chemotherapy may be offered too, but the
up” after meals. Bleeding from the stomach outlook is poor.
Males over 40 years of age are most likely to may cause hematemesis (bloody vomiting ),
develop stomach cancer. Risk factors include melena (black, tarry stools), or anemia. The Cancer in the lower stomach
infection with Helicobacter pylori; smoking; diagnosis is made by endoscopy with biopsy This colored barium study shows the large,
a family history of this cancer; a diet rich in or a barium study. Gastrectomy (surgery to irregular shape of a tumor in the lower stomach.
remove some or all of the stomach) is the CT, MRI, and ultrasound scans may be used to
most common treatment; tumors at the top find out if the tumor has spread elsewhere.

464

DISEASES AND DISORDERS

LOWER DIGESTIVE TRACT DISORDERS

Many of the disorders affecting the intestines (bowels) and rectum are caused by DIARRHEA AND
inflammation, as in inflammatory bowel disease (IBD). Others may be due to structural CONSTIPATION
changes, as in diverticulosis. Cancers of the colon and rectum are common.
Acute diarrhea (frequent loose or liquid
CELIAC DISEASE digestive system. This reaction damages the IRRITABLE BOWEL bowel movements) is often due to viral or
villi, causing them to flatten and interfering SYNDROME bacterial infections causing gastroenteritis
A disorder of the small intestine, celiac with their normal function. The resulting (inflammation of the stomach and the
disease is caused by an immune system symptoms vary widely, but include a swollen A common long-term complaint with no small intestine). Diarrhea can also have
reaction to gliadin, a gluten protein abdomen, vomiting, diarrhea (typically pale, structural or biochemical origin, irritable a variety of other causes. Constipation
found in wheat and some other grains. foul-smelling, and bulky), fatigue, weight loss, bowel syndrome (IBS) leads to abdominal (infrequent or hard stools or difficulty in
and stunted growth. Celiac disease is more discomfort and altered bowel habits. passing stools) is often due to inadequate
The lining of the small intestine has millions common in women and can run in families. It intake of dietary fiber and fluid, but may
of tiny, fingerlike projections called villi, which often coexists with other autoimmune disorders Occurring mainly in people aged 20–30 years also be caused by a variety of bowel
absorb nutrients from food. In celiac disease, such as type 1 diabetes mellitus. of age, IBS affects up to 1 in 5 people and is two problems, including tumors.
the immune system reacts against gluten in the to three times more common in women than
The condition is diagnosed by finding men. It causes bouts of recurrent abdominal Intestinal bacteria
antigliadin antibodies in the blood, endoscopy pain and possibly bloating, associated with E. coli bacteria live in the intestines. Most
(see p.462), and taking a biopsy (tissue sample) changes in the frequency or appearance of strains are harmless, but some cause severe
of the small intestine. Affected people need stools. The pain is often relieved by defecation. cramps, vomiting, and bloody diarrhea and
to follow a strict, lifelong gluten-free diet The cause is unknown, but IBS can be triggered may produce toxins that damage the kidneys.
(avoiding wheat, rye, and barley) to clear up by a bout of gastroenteritis. It is a long-term,
symptoms, and take dietary supplements to intermittent disease; flare-ups can be brought
correct nutritional deficiencies. on by alcohol, caffeine, stress, and certain foods.
It is diagnosed by the symptoms, physical
Flat surface due to loss of villi examination, and blood tests. Lifestyle changes,
dietary modification, and increasing soluble
Celiac disease fiber intake can lessen symptoms. During
This light micrograph of a section through the flare-ups, drugs may help regulate bowel habits
duodenum of a patient with celiac disease shows and relieve abdominal spasms.
the loss of villi from the surface. As a result, the
intestine is less able to absorb nutrients effectively.

CROHN’S DISEASE severe diarrhea (often with blood), loss of ULCERATIVE COLITIS with UC have a greatly increased risk of
appetite and weight, profound fatigue, and developing colon cancer. Diagnosis is made
This rare autoimmune disorder does not anemia. Because it is an autoimmune disorder, This rare disorder of the large intestine by endoscopy (see p.462), barium studies, and
have a cure, and causes inflammation Crohn’s disease may also cause liver, skin, and causes inflammation and ulceration blood tests. Treatment involves using drugs to
anywhere along the digestive tract, eye problems and inflamed joints. Drugs can (open sores) in the colon and rectum. suppress or modulate the immune system and
sometimes in several places at once. be taken to reduce inflammation and suppress to control inflammation and diarrhea. Up to 40
the activity of the immune system, and the Ulcerative colitis (UC) usually affects teenagers percent of affected people eventually have
The disease affects both sexes equally and can disease may be in remission for years. Often, and young adults or, less commonly, adults surgery to remove the colon and rectum, which
run in families. It usually appears in teenagers surgical removal of diseased areas is necessary. between 50 and 70 years old. The inflammation cures the condition.
and young adults. The inflammation in Crohn’s occurs in the mucosa (lining) of the colon and
disease involves all of the intestinal wall and Stricture rectum, leading to ulceration with bleeding and Inflamed large
follows two main patterns. In stricturing pus. Symptoms, which come and go over intestine
disease, the affected area narrows, eventually Large intestine months or years, typically include diarrhea
causing blockages. In fistulizing disease, mixed with blood and mucus, abdominal pain, Cecum
abnormal passageways form between affected Terminal ileum fatigue, and weight loss. UC is believed to be
areas and nearby structures. Symptoms Area of an autoimmune disorder; it may also cause skin
fluctuate but may include abdominal pain, and eye problems and inflamed joints. People
inflammation
Patches of inflammation Inflammation and ulceration Inflamed
Crohn’s disease typically affects the ileum (the Cecum In ulcerative colitis, the inflammation is normally rectum
last part of the small intestine), but may occur in Rectum continuous, extending from the rectum up the
patches anywhere from the mouth to the anus. colon to a varying extent, and sometimes
Strictures in the bowel can lead to obstruction. reaching all the way to the cecum (“pancolitis”).

465

LOWER DIGESTIVE TRACT DISORDERS

Wall of appendicitis begins with sudden, severe pain
colon that starts in the center of the abdomen and
shifts down into the lower right area, where
DIVERTICULAR DISEASE APPENDICITIS the appendix is situated. The condition usually
causes a loss of appetite and sometimes fever,
The development of diverticula (pouches) Hard, dry stools Blood An inflamed appendix (appendicitis) nausea, and vomiting. Diagnosis is based on
in the colon wall is called diverticulosis. vessel causes severe abdominal pain and the symptoms and on
Problems can arise if diverticula become requires urgent medical removal. an examination and
inflamed and infected. 1 Hard stools blood tests. Treatment
If stools are small, hard and dry, the smooth Infection and blockage in the appendix can may be antibiotics or
The pea-to grape-sized pouches typically muscles in the bowel wall must contract harder cause it to fill up with pus, making it swell. immediate surgery
develop from the age of 40 onward and to push them along than if they are soft and large. As this swelling grows worse, the appendix (removal of the
are found in many older people. Risk factors starts to die and infected pus forms around appendix), which
include increasing age, constipation, and a Pouches can trap bacteria it (suppuration). Eventually the appendix can be performed
low-fiber and high-fat diet. Diverticula usually and become inflamed ruptures (bursts) and infected material leaks by laparotomy
produce no symptoms, but in some cases they out, causing peritonitis (inflammation of the (open surgery) or
can cause bloody stools, bloating, abdominal Diverticula push membrane covering most of the abdominal laparoscopy
pain, diarrhea, or constipation. The pouches through colon wall organs), which can be fatal. Typically, (keyhole surgery).
can trap bacteria and become inflamed (acute
diverticulitis); this condition typically causes 2 Pouches form Large Small
left-sided lower abdominal pain, with fever Increased pressure from pushing can cause intestine Intestine
and later vomiting. Diverticulosis is diagnosed the mucosa and submucosa to push through
by viewing (colonoscopy) or imaging of the weak points in the colon wall, forming pouches. Appendix Site of appendix
colon (barium studies). Acute diverticulitis is The appendix is a blind-ended tube connected
diagnosed by CT scanning. Diverticulosis can, to the cecum, which is part of the colon.
if necessary, be treated with a high-fiber diet Its removal seems to have no effect on the
and fiber supplements. Acute diverticulitis function of the digestive or immune system.
usually clears up in response to antibiotics

and resting of the bowel, but in severe
cases surgery may be required to remove
the affected area of bowel.

cancer, increasing age, smoking, a diet high in

red meat and low in fruit and vegetables, lack

COLORECTAL CANCER of exercise, excess alcohol intake, and a history Colon

A malignant tumor of the rectum and/or of inflammatory bowel disease. Symptoms Intestinal
colon (bowel) is one of most common may include a change in bowel habit and wall
forms of cancer in industrialized nations stool consistency; mucus or blood in stools;
and a leading cause of cancer deaths.
tenesmus (a sensation of not fully emptying
Around 1 in 20 people will have colorectal
cancer in their life. It affects both sexes equally, the bowels); abdominal pain; anemia; and loss Artery
and most cases occur in people over 50 years of weight or appetite.
of age. Risk factors include having a colorectal
polyp (a slowly developing overgrowth of the A large tumor may block the bowel,
colon or rectum lining), a family history of this
causing abdominal pain and bloating with Tumor invades
Colon cancer
This color-enhanced X-ray shows a tumor within vomiting and constipation. Tumors may be intestinal
the colon. The patient was given a barium enema,
which highlights the abnormality. detected by imaging (barium studies, CT, and wall

PET scans), viewing (endoscopy), and blood Vein
tests for chemicals called tumor markers.

Treatment of the condition depends on how

Tumor in the colon much the tumor has spread and includes Invasive colonic tumor
surgery and chemotherapy; early cancers can Cancers can spread directly, by invasion of local
be cured. Screening programs to detect structures such as the colon wall, or indirectly,
the disease early exist in many countries. via the bloodstream and lymphatic system.

HEMORRHOIDS bleed, showing as bright red blood on the Rectum
stools and/or toilet paper, or blood dripping Vein network
The veins in the anus and rectum may into the toilet bowl. Larger internal hemorrhoids Anal canal
become varicosed (swollen), causing may prolapse out of the anus, typically after
them to protrude and be liable to bleed. defecation, but often go back by themselves Internal hemorrhoid
or may be pushed back in by hand. External
Hemorrhoids can result from straining to pass hemorrhoids develop outside the anus. Both External hemorrhoid
stools, so are common in constipation and types can form itchy, tender, painful lumps.
chronic diarrhea. Internal hemorrhoids occur Piles can be found by proctoscopy (viewing Hemorrhoids
within the rectum and are painless but may the anus and rectum). Treatments include The venous network on the left is normal. On the
increasing fluid and fiber intake, ointments, right, the veins have become swollen, protruding
injections, banding, laser therapy, and surgery. into the anus (internal hemorrhoids) or
developing outside it (external hemorrhoids).

466

DISEASES AND DISORDERS

LIVER, GALLBLADDER, AND PANCREAS DISORDERS

Producing substances vital to digestion, the liver, gallbladder, and pancreas enable the JAUNDICE
absorption and metabolism of food, drinks, and medicines and other chemicals. They
are vulnerable to infection, cancerous change, and damage by alcohol and other toxins. Old red blood cells are broken into
bilirubin in the liver and, normally,
Acetaldehyde Fat-laden cell Liver cell excreted into the bile. The yellowing of
Water jaundice results from an excess of bilirubin
ALCOHOLIC LIVER DISEASE Alcohol in the blood. In hemolytic jaundice, it is
Liver cell released directly into the bloodstream.
Prolonged, excessive alcohol intake causes In liver disease, bilirubin seeps into the
increasing damage to liver cells, and can bloodstream because the liver is unable to
eventually result in permanent harm. metabolize or excrete it properly.

Alcohol is absorbed in the small intestine and 1 How damage occurs 2 Fatty liver Yellow sclera
enters the liver. There, it is metabolized (broken When alcohol (ethanol) is broken down by Fat builds up in the liver cells, and eventually The sclera (white of the eye) appears yellow
down) to form fat and chemicals, some of the liver, it produces fat and a chemical called the deposits become so large that a cell swells because the overlying conjunctiva contains
which can damage liver cells. The first sign of acetaldehyde, which is toxic to the liver but is and the nucleus is pushed to the side of the cell. excessive amounts of bilirubin.
damage is fatty liver, in which large droplets of itself processed into water and carbon dioxide. The liver becomes enlarged.
fat collect in liver cells. There are no symptoms, VIRAL HEPATITIS
but blood tests may show impaired liver Damaged tissue Scar tissue
function, and ultrasound scans show the liver The most common viral causes of
to be enlarged and fatty. Continued drinking 3 Alcoholic hepatitis 4 Cirrhosis hepatitis (liver inflammation) are the
causes alcoholic hepatitis (liver inflammation). With continued heavy drinking, liver cells Repeated alcohol abuse causes permanent hepatitis A, B, and C viruses.
Abstaining from alcohol will stop or delay become swollen, damaged, and surrounded by scarring and fibrosis. The liver becomes nodular,
progression, allowing the liver to recover. white blood cells. Some cells die and are replaced shrinks, and cannot function normally. As a result, Hepatitis A virus (HAV) is spread by food and
with fibrous tissue (fibrosis); others regenerate. liver failure and portal hypertension develop. water contaminated with infected stools. It
Symptoms include liver enlargement, produces jaundice, fever, nausea, vomiting,
jaundice, and ascites (fluid within the abdomen). smaller branches to supply it. If the liver is and upper abdominal pain. Most people recover
It is diagnosed by liver function blood tests. scarred and fibrosed, blood flow is impeded, within 2 months. Hepatitis B virus (HBV) and
Mild cases clear up with abstinence, but severe leading to back-pressure in the portal system. hepatitis C virus (HCV) are spread by infected
cases may be fatal. In cirrhosis, liver tissue is This causes the veins to become distended and body fluids such as blood or semen. HBV causes
replaced by fibrous scar tissue, and some of liable to bleed. Varices (swollen veins) in the acute hepatitis, which may lead to chronic
the damaged tissue forms nodules. Symptoms esophagus sometimes bleed severely and hepatitis. HCV often has no symptoms initially,
include ascites, jaundice, enlarged breasts and result in hematemesis (vomiting of blood), but may lead to chronic hepatitis. Chronic viral
shrunken testes in men, red palms, pruritis, which can be life-threatening. Bleeding may hepatitis may result in cirrhosis and liver
weight loss, confusion, and coma. If the liver be stopped by the use of rubber bands, to seal cancer, but antiviral drugs can reduce the risks.
fails, transplant the veins, or sclerotherapy (injection of a
is needed. chemical to cause varices to scar). Hepatitis B
This virus is commonly transmitted by sexual
Esophageal PORTAL HYPERTENSION The spleen may enlarge, and fluid may contact, blood transfusion, sharing needles for
varices collect in the abdominal cavity. In addition, drug use, and nonsterilized tattoo equipment.
Stomach Raised pressure in the portal vein is poor liver function may cause hepatic
Distended usually due to alcoholic cirrhosis, but encephalopathy, resulting in confusion and
veins (varices) Enlarged schistosomiasis (a parasitic worm forgetfulness. Portal hypertension is treated
spleen infection) is a major cause worldwide. with beta-blocker drugs, which lower the
can easily blood pressure, or sometimes surgery to
bleed into the The portal venous system collects blood from reduce pressure in the portal venous system.
the esophagus, stomach, intestine, spleen, and Ultimately, a liver transplant may be needed.
esophagus. pancreas. The veins merge to form the portal
Inferior vein, which enters the liver and splits into
vena cava
Blood from
Liver stomach

Portal vein Blood from Obstructed blood flow
spleen Restricting the blood flow into the portal system
raises the pressure behind the blockage, causing
the veins to distend and the spleen to enlarge.

467

LIVER, GALLBLADDER, AND PANCREAS DISORDERS

LIVER TUMORS LIVER ABSCESS surgery), followed by antibiotics. Left untreated, GALLSTONES
the mortality rate from this condition is high.
Growths within the liver are usually An abscess, or pus-filled mass, in the Abscesses may also result from fungal or Hard masses formed from bile, gallstones
benign (non-cancerous), but cancer may liver is most commonly due to bacteria amebic infections, especially in the tropics. can occur anywhere in the biliary ducts
spread there from other parts of the body. that spread from elsewhere in the body. but usually form in the gallbladder.
Pyogenic abscess
Benign liver tumors are most often either a A pyogenic (bacterial) abscess is commonly Abscesses may be single or multiple, and usually Gallstones may be single or multiple and vary
hemangioma (mass of blood vessels) or an caused by bacteria spreading from an occur in the right lobe of the liver. They are more in size, some more than an inch wide. Most
adenoma (overgrowth of normal cells). They abdominal infection (such as appendicitis, common in people with diabetes mellitus or a are made primarily of cholesterol, some are
generally cause no symptoms and require no cholangitis, diverticulitis, or weakened immune system. “pigment stones” made of bilirubin (produced
treatment. Cancerous tumors are usually due to perforated bowel) or from the
a cancer having spread from another area of the blood. It causes a sudden Vein from red blood cells) and calcium,
body, most commonly from a cancer in the feeling of illness, loss of and the rest are a mixture of these
colon, stomach, breast, ovary, lung, kidney, or appetite, high fever, and Gallbladder Pus-filled
prostate. The most common cancer to arise pain in the upper right of abscess two types. Gallstones are more
within the liver (primary liver cancer) is a the abdomen, although it common in women, Mexican Americans,
hepatoma, which may result from chronic viral can be present for weeks Common Native Americans, those who are overweight,
hepatitis, cirrhosis, or exposure to toxins. It with few symptoms. The bile duct and older people. They take years to form and
causes abdominal pain, weight loss, nausea, abscess may be detected often cause no symptoms unless they become
vomiting, jaundice, and a mass in the abdomen. by ultrasound or CT lodged in the ducts that drain the gallbladder
It is diagnosed by imaging, such as ultrasound scanning. It is treated by or the pancreas. If this happens when the
or CT scan, and biopsy. Treatment may include draining the pus using a gallbladder contracts (such as after a fatty meal),
surgical removal of the tumor, chemotherapy, needle (either done it can cause biliary colic: steadily increasing,
radiation therapy, and liver transplant. Prognosis through the skin or severe upper abdominal pain, often with nausea
depends on whether the cancer has spread. during abdominal Liver and vomiting. The stones may be detected by
ultrasound and, if painful, the gallbladder may
be surgically removed (cholecystectomy).

Kidney Spine Pancreas vomiting and fever, but the pancreas heals Common Gallstone in
without any loss of function. In chronic hepatic duct cystic duct
Scan of abdomen showing pancreatitis PANCREATITIS pancreatitis, recurrent attacks of inflammation Cystic A stone can
The blue area on this CT scan through the cause permanent damage and loss of function, cause the
upper body shows an enlarged pancreas Inflammation of the pancreas, or which can lead to diabetes mellitus and duct gallbladder to
caused by pancreatitis. pancreatitis, is due to enzymes produced reduced ability to digest fats. become
by the pancreas damaging the pancreatic Bile swollen,
CANCER OF THE PANCREAS tissue itself (autodigestion). The major causes of pancreatitis are inflamed, and
gallstones, if they obstruct the drainage of the Gallstone in common infected (acute
A malignant tumor of the pancreas is a The pancreas produces enzymes to aid the pancreas, and excessive long-term alcohol bile duct cholecystitis).
common cause of cancer deaths because digestion of food in the duodenum. However, intake, which damages the function of A stone can block the flow of This is a surgical
it causes no symptoms in its early stages if these enzymes are activated within the pancreatic cells. Other causes include bile into the duodenum, emergency.
and may not be found until it has spread. organ, they digest it. This causes the pancreas injury to the pancreas, and certain drugs leading to jaundice. Stagnant
to become inflamed. The condition may be and viral infections. The disorder is bile above the stone may Gallbladder
This disease is most common in males over the acute (sudden-onset) or chronic (long-term). diagnosed by finding elevated levels become infected (cholangitis).
age of 60. The risk factors for pancreatic cancer Acute pancreatitis causes severe upper of the pancreatic enzyme amylase in the Gallstones
include smoking, obesity, chronic pancreatitis, abdominal pain, which penetrates through blood and particular changes on CT scan. Gallbladder
poor diet (lack of fruit and vegetables, excess into the back with severe nausea and/or It is treated with analgesics and antibiotics, Bile Common
red meat), and a family history. Symptoms and by addressing the underlying cause. bile duct
do not appear until late in the disease. They Cancer in the head of the pancreas may block Gallstones
include upper abdominal pain, penetrating the flow of bile from the gallbladder, leading to Cystic duct
through to the back, and severe weight loss. jaundice, generalized itching, pale stools, Gallstone impacted
and dark urine. Diagnosis is made by Ampulla of Vater Common bile duct in common
finding tumor markers (chemicals bile duct
released by cancer) in the blood, CT Tail of pancreas
scanning, and biopsy. Patients may be
offered surgery but treatment can Head of pancreas Pancreatic
only relieve symptoms, with few duct
patients surviving for more than six
months after diagnosis. Body of
pancreas
Sites of pancreatic cancer
Most tumors occur in the head of the Duodenum
pancreas. Some develop at the ampulla of Vater,
where the pancreatic duct and common bile duct
join, causing biliary obstruction and jaundice.

468

DISEASES AND DISORDERS

KIDNEY AND URINARY PROBLEMS

The renal system of kidneys, ureters, bladder, and urethra clears waste from the blood. The kidneys also play
a role in the renin-angiotensin system, which regulates blood pressure, and in vitamin D metabolism, and
secrete erythropoietin to stimulate red blood cell production. Kidney disease affects all of these functions.

URINARY TRACT INFECTIONS KIDNEY STONES

One of the most common types of infection, urinary tract infections arise when the normally sterile urine is Also known as calculi, these stones are
contaminated by bacteria from the bowel. Bacteria may pass up the urethra to the bladder or, less commonly, formed from hardened deposits of waste
through the bloodstream to the urinary tract. The presence of sugar in the urine, as in diabetes, or stones in materials that pass through the kidneys;
the urinary tract can enable bacteria to take hold, especially where there is any obstruction to urinary flow. they are most common in young men.

GLOMERULONEPHRITIS CYSTITIS The exact cause of kidney stones is unknown,
but predisposing factors include diseases
In this complex condition, the glomeruli Inflammation of the bladder lining, or producing high levels of calcium or other
(the tiny filtering units within the cystitis, is usually caused by infection, compounds, or urinary infection. In some
kidneys) are damaged by inflammation. most commonly with bacteria normally cases, the stones are associated with genetic or
found in the bowel. metabolic disorders, such as gout. Stones are
Glomerular inflammation may occur alone, as not usually painful until they pass into the
a result of an immune system disorder, or due More frequent in women—in whom the urethra ureter, when they may cause excruciating pain
to infection. It may also be caused by other is only 1½ in (4 cm) long, making bacterial with blood in the urine or infection.
diseases that affect the whole body, such as SLE access easier—cystitis usually causes symptoms
(see p.461) or polyarteritis nodosa (see p.461). such as pain when urinating, frequent need to Diagnosis is confirmed by CT scans. About
Damaged glomeruli can no longer filter wastes urinate, abdominal pain, fever, and blood in the 40 percent of stones pass out in the urine, but
effectively from the blood, so problems include urine. In men, cystitis is rare and usually caused some give rise to blockage, infection, backflow,
kidney failure, nephrotic syndrome (protein in by a disorder of the urinary tract. The immune or kidney failure, and need to be removed.
the urine, high cholesterol, and low protein in system can overcome low levels of bacteria, Surgical procedures include lithotripsy, external
the blood), and nephritic syndrome (body tissue but once cystitis is established, antibiotics may shock waves to break up the stone so it can
swelling, protein and blood in the urine). be needed to prevent chronic infection and pass in the urine; ureteroscopy, in which a tube
keep it from spreading to the kidneys. Diagnosis is passed up the urinary tract to reach the stone;
The condition is investigated by blood tests, is made from the symptoms and testing urine or open surgery.
urine analysis, and X-ray, MRI, or biopsy (taking for white blood cells, nitrites, and blood.
a tissue sample) of the kidney. The management Bacterial cause of infection Growth of kidney stones
and prognosis depend on the cause of the The bacterium causing the infection can be E. coli is a bacillus that inhabits the bowel and Most kidney stones are small and pass out of the
condition, its severity, and other diseases that confirmed by analyzing a sample of urine, and perineum. It is usually harmless but can migrate body in the urine. The biggest stones slowly form
may be present. tests may be done to find which antibiotic will to other organs, where it may cause infection. in the calyces and renal pelvis at the center of the
eradicate it. Drinking plenty of clear fluids and It is responsible for most cases of cystitis. kidney, developing a horned shape.
emptying the bladder soon after sexual
intercourse helps prevent further infections. Other forms of cystitis include nonbacterial Kidney Minor calyx
infections that may be triggered by certain stones
foods or drinks, chlamydia, and urethral
syndrome, in which diseases inflaming the Major
urethra and bladder cause cystitis symptoms. calyx

Inflamed glomeruli PYELONEPHRITIS bladder to the kidneys via the ureters. More
Light micrograph of three glomeruli (dark blue rarely, other organisms such as proteus,
areas) in a kidney affected by glomerulonephritis. Inflammation of the kidneys due to staphylococcus, or tuberculosis (TB) may
A sample of the kidney tissue taken in biopsy is bacterial infection, is called pyelonephritis. be responsible for the condition. Symptoms
analyzed and used to diagnose the condition. It is usually caused by bacteria entering include painful or frequent urination, fever,
the urinary tract through the urethra. back pain, blood in the urine, nausea, and
fatigue. In rare cases, a kidney abscess may
Pyelonephritis is a more serious infection than form, or the infection can spread in the blood.
bacterial cystitis (see above), although if treated Diagnosis is made by testing the urine for
promptly does not cause permanent damage bacteria. X-ray, ultrasound, or other scans
to the kidneys. Around 80 percent of cases are may also be done to show any stones or other
caused by a virulent subgroup of the Escherichia damage to the kidneys. Long courses of
coli bacterium, which has migrated from the antibiotics may be needed to clear the infection,
and surgery may be required to correct resulting
problems such as kidney stones (see right).

469

KIDNEY AND URINARY PROBLEMS

KIDNEY FAILURE the kidney itself; and by conditions that cause DIALYSIS
obstruction of urinary flow. Certain drugs,
Acute loss of kidney function can be including NSAIDs, anti-inflammatories, some For people with acute or advanced chronic and a vein). In the machine, waste and excess
immediately life-threatening, while antibiotics, and drugs for heart and cancer kidney failure, dialysis may be necessary to water diffuse into dialysate (dialysis fluid), and
chronic kidney failure involves more disease, may also reduce kidney function. replace the kidneys’ function of filtering the the filtered blood is then returned to the body.
gradual, progressive deterioration. Symptoms of acute kidney failure include blood. In hemodialysis, the most common The process takes several hours and is repeated
nausea, vomiting, low urine output, fluid form, blood passes from the patient into a two or three times a week. Another option
The kidneys’ main role in clearing the blood of retention, breathlessness, confusion, and machine via a cannula in a large vein (or is peritoneal dialysis, which makes use of the
waste products can be affected suddenly by eventually coma. It is treated by dialysis, a a surgically created join between an artery membrane around the abdominal organs.
severe conditions such as shock, burns, blood system for removing waste products in the
loss, infection, and heart failure; by diseases of blood, until the kidneys recover. Peritoneal dialysis

Chronic kidney failure is the progressive Dialysate is infused into the abdominal cavity via
loss of renal (kidney) cells and is a feature of
long-term disorders including kidney disease, a catheter. Waste from the blood passes into the
diabetes, hypertension (high blood pressure),
and inherited disorders such as polycystic fluid through the peritoneal membrane, and
kidneys. Treatment for kidney failure involves
dealing with the underlying cause of the later the fluid is replaced with a fresh supply.
condition and supporting production of vitamin
D and red blood cells. If the kidneys fail, dialysis Peritoneal Peritoneal
and then kidney transplant may be necessary. membrane membrane Capillary wall

Dialysate

Kidneys Dialysate
Red blood cell
Spine Waste product

Polycystic kidneys
Cysts slowly grow within the renal tubules. They
can reach a massive size by adulthood, gradually
damaging the normal kidney tissue and causing
deterioration in kidney function.

Urine in Uterus Weakened pelvic
the bladder floor muscle

INCONTINENCE KIDNEY TUMORS

Uncontrollable urinary leakage, or Kidney tumors commonly metastasize—
incontinence, is increasingly common tumors that spread to other organs— but
with age in both men and women. cancer may also develop from the kidney
tubule cells.

There are several forms of urinary incontinence, NORMAL BLADDER Pelvic floor INCONTINENT BLADDER The first signs are usually hematuria (blood in
such as stress incontinence when straining; urge Urethra muscle Stress incontinence the urine), back pain, abdominal swelling, and
incontinence, causing an uncontrollable need to This results from weakness in the external urethral sphincter anemia. Less often, symptoms relating to the
urinate; and overactive bladder syndrome, in and pelvic floor muscles. Coughing or straining causes pressure kidneys’ other functions, such as hormonal
which there is an urgent need to urinate but no in the bladder to exceed that in the urethra, leading to leakage. syndromes and high blood pressure, develop.
flow. Various illnesses and physical weaknesses Kidney cancers spread early, particularly to the
can cause incontinence, such as prostate lungs, liver, and bone, and symptoms of
problems in men and poor muscle tone in metastasis, such as breathlessness and bone
women. Diagnosis may include urodynamic pain, can occur first. Diagnosis is made by
tests to assess urinary tract function, including ultrasound and CT scans, and biopsy (tissue
flow rates, pressure in the bladder, and urethral sampling) to confirm the stage of the tumor.
sphincter action. Management may involve diet Treatments include removal of the kidney,
and lifestyle changes, physical therapy, drug chemotherapy, and immunotherapy.
treatments, or occasionally surgery.

BLADDER TUMORS Bladder tumors are more common in smokers; anemia develop. Treatments include radiation
in men; and in people whose jobs involve therapy, removal of the tumor or the bladder,
Most tumors in the bladder arise in the exposure to carcinogens in the rubber, textile, and diversion of urine via the bowel.
lining cells on the bladder wall, but they and printing industries; and those with chronic
can also develop from muscle and other irritation from bladder stones or the tropical Bladder cancer cell
cells within the bladder. worm infection schistosomiasis. Growth often Most bladder cancers develop from the epithelial
goes unnoticed; the tumor may only be found cells lining the bladder, and can be very advanced
when symptoms such as blood in the urine or before they cause the typical symptoms of blood
urinary blockage arise, or when weight loss or in the urine or an abdominal swelling.

470

DISEASES AND DISORDERS

FEMALE REPRODUCTIVE SYSTEM DISORDERS

The functioning of the female reproductive system involves complex physical and
hormonal interactions, and disorders can result from disturbances in a number of
different tissues. In some cases genetic influences play a role.

Cancerous tumor

BREAST CANCER ENDOMETRIOSIS

The most common cancer in women, it In this condition, cells belonging to the Endometriosis
can develop in part of the breast or in the endometrium (uterus lining) grow in Endometrial cells, shown in green and yellow on
nearby lymph nodes. It accounts for 20 parts of the body outside the uterus. this electron micrograph, are lying on the surface
percent of female cancer deaths. of an ovarian cyst. They respond to cyclical
Abnormal growths of endometrial cells are hormones, causing bleeding into the pelvic cavity.
Breast cancer most often occurs in women Breast cancer mammogram most commonly found on the ovaries or in the
aged 45–75 years, and it is rare before the age A mammogram is an X-ray of the breast. It shows abdominal cavity, but they can also occur in period pain, vaginal or rectal bleeding, pain
of 35 years. It affects 1 in 9 women. A small any tumors or other lumps as dense, white areas the lungs, heart, bone, and skin. The cause is during intercourse, or reduced fertility. Treatment
number of cases occur in men. Up to 1 in 10 in the breast tissue. Screening for breast cancer is not known, but theories include reverse includes anti-inflammatory drugs, hormones
cases are due to genetic predisposition; the done by a mammogram. menstrual flow or cells spreading via blood such as progesterone or the contraceptive pill,
most important genes involved are called and lymph vessels. Some women have no or surgery to remove the deposits.
BRCA1 and BRCA2. Other risk factors include a tissue sample). Further tests, such as blood symptoms, but others experience severe
lack of exercise, obesity, excessive alcohol tests, X-rays, or CT scans, may be done to
consumption, hormone therapy, and previous find out if the cancer has spread. Possible Subserosal Fallopian tube
breast cancer). treatments include surgical removal of the
cancer, chemotherapy, and radiation therapy. FIBROIDS
The most common type of breast cancer Symptoms need to be detected as soon as
is ductal adenocarcinoma, which arises in the possible for the best chance of treatment, so Intramural Submucosal These noncancerous growths of the
milk ducts, but lumps may appear anywhere women aged 50–75 years (who are at highest Ovary Cervical smooth muscle inside the uterus
in the breast tissue or in the nearby lymph risk) are offered screening mammograms. often cause no symptoms, but some
nodes. The first symptoms are often a painless Uterus can grow to an enormous size.
lump, skin changes, or a nipple that becomes
inverted (turned inward) or develops a Fibroids affect about 1 in 5 women and are
discharge. The cancer may be diagnosed by more common in those who have never been
a physical examination, or by ultrasound or pregnant. It is not known why they develop,
mammogram imaging and biopsy (study of but they are dependent on the hormone
estrogen, so they usually shrink after
BREAST LUMPS Sites of breast lumps Sites of fibroids menopause. They can cause bloating or
Lumps can develop anywhere Fibroids can occur in any part of the uterus swelling; abdominal and back pain; heavy,
There are several possible kinds of breast in the breast, but occur most wall and are named according to their site: for painful periods; and infertility. During childbirth,
lump, of which cancer is only one. The most commonly in the upper outer example in the cervix (cervical), or in the tissue large fibroids can cause obstruction. Fibroids
common cause of breast lumps in women quadrant, near the armpit. layer in which they occur. may be located by an ultrasound scan and
before menopause is fibroadenosis, or Fibroadenoma may be treated with anti-inflammatory drugs
fibrocystic disease. In this condition, some or hormones. Surgery may be needed to
of the breast cells become overactive, Cyst remove persistent problematic growths.
possibly in response to hormonal changes,
producing a thickened but noncancerous Fatty MENSTRUAL DISORDERS cycle, and luteinizing hormone (LH) stimulates
area (a fibroadenoma) that can be felt as a tissue thickening of the uterus lining in the second
lump. Typically, women notice one or more A woman’s usual menstrual cycle can be half with estrogen, progesterone, and other
painful lumps, which vary through the Nonspecific disturbed by a variety of factors, both hormones involved. Short-lived disorders are
menstrual cycle. lumpiness physical and psychological. common because of variation in these
hormones, or due to dieting, lowered immune
Cysts (lumps filled with fluid) are more The cycle is controlled by complex hormonal or mental states, medications, or other diseases.
common in women near menopause, and influences from the brain, ovaries, and other Heavy periods, dysmenorrhea (painful periods),
may cause nipple discharge. Usually, a lump tissues. Follicle-stimulating hormone (FSH) or amenorrhea (missing a period), may occur
subsides over the next menstrual cycle, but stimulates egg release in the first half of the with no serious effects, Bleeding at abnormal
persistent lumps need further investigation times, or recurrent or persistent period
to rule out cancer. Another possible problems may require further investigation.
problem is nonspecific lumpiness and
tenderness, which may occur or get worse
before menstrual periods; this may also be
related to hormonal changes.

471

FEMALE REPRODUCTIVE SYSTEM DISORDERS

OVARIAN CYSTS During the menstrual cycle, a follicle grows disorder in which multiple cysts grow. PCOS is Cyst Fluid-filled
around an egg within the ovary, and after the associated with hormone imbalance and high Follicular and cyst
These fluid-filled sacs in the ovary are egg is released, the empty follicle (corpus testosterone levels, and can cause hairiness, corpus luteum
related to cyclical changes; most are luteum) shrinks away. Both growing and empty obesity, irregular periods, reduced fertility, and cysts usually
benign but a few can be cancerous. follicles can develop into “functional cysts,” the acne. Diet and weight loss may help control it, shrink at the end
most common type, which usually disappear but some women need hormone treatment. of the menstrual cycle.
on their own. However, 1 in 10 women have Occasionally, cysts can become cancerous, Those that persist need
polycystic ovarian syndrome (PCOS), a especially if they grow after menopause. further investigation.

OVARIAN CANCER lymphatic vessels and the blood. It may be CERVICAL CANCER CERVICAL SCREENING
diagnosed by examination, scans, or biopsy
Although less common than breast or (study of a tissue sample). As much of the The development of cancer in the cervix The “smear” or “pap” test is a regular
cervical cancer, ovarian cancer can be tumor as possible may be removed by surgery, is most common in women aged 30–40. screening for cervical cancer and has been
more dangerous, since it often produces and chemotherapy used to destroy cancer It has been linked to infection with a successful initiative in reducing deaths
no symptoms until it has already spread. cells before and after surgery. human papillomavirus (HPV). from the disease. During the test a sample
of cells is removed from the cervix and
Ovarian tumor examined for abnormalities. Most cell
changes are minor and disappear within
Most often developing in women aged 40–70 Ovarian cancer Cervical cancer is one of the most common 6 months, but more serious or persistent
years, ovarian cancer is more common in This colored MRI scan of the abdomen shows cancers diagnosed in women. It develops changes may need treatment. Precancerous
women with a family or personal history of ovarian cancer (brown, upper center) within the slowly and can be detected through screening cells can be detected early; they are most
breast, ovarian, or colon cancer; those who tissues contained inside the pelvic cavity. and treated at an early stage. Risk factors often found in women under 35.
have prolonged periods of uninterrupted include having multiple sexual partners,
ovulation, such as childless women or those smoking, and having many children. The most Cervical smear test
who give birth late in life; and obese women. common symptom of cervical cancer is The darker areas of this smear test show
abnormal vaginal bleeding. Diagnosis is made precancerous cells. Cervical screening can
Oral contraceptives may give some by colposcopy—an examination of the cervix help detect the disease at an early, treatable,
protection against ovarian cancer, because they using a magnifying device—and biopsy of the stage and prevent cancer from developing.
suppress ovulation, but hormone therapy (HT) tissue. Other tests may be carried out to check
may slightly increase the risk because the whether the cancer has spread. The cancer
cancer is often sensitive to estrogen. Symptoms is treated by surgery to remove part or all of
develop late in the disease. They may include the cervix or uterus, and chemotherapy or
abdominal discomfort and swelling, back pain, radiation therapy may also be needed. The
weight loss, and, less commonly, irregular outcome depends on how severe the changes
vaginal bleeding, trapping of urine in the are and how far the cancer has spread. The
bladder, and peritonitis (inflammation of the development of a vaccine against HPV
abdominal lining). The cancer can spread to infection should reduce its frequency.
the uterus and intestines, and on through the

UTERINE CANCER intercourse, sometimes with pain or discharge. PELVIC INFLAMMATORY Risk factors include a new sexual partner,
The cause is unknown but is linked to excessive DISEASE previous PID or STD, or insertion of an IUD
Most cancers in the uterus arise from a estrogen. Risk factors include obesity (fat cells (intrauterine device). There may be abnormal
tumor in the lining (endometrium). In produce some estrogen); early menarche Inflammation of the uterus and fallopian vaginal bleeding, pain, discharge, fever, or back
rare cases a sarcoma (cancer of the (onset of periods), late menopause, or tubes can cause infertility and an pain, but some women have no symptoms.
muscle) can develop. childlessness; and endometrial hyperplasia increased risk of ectopic pregnancy. Left untreated, PID can cause inflammation,
(overgrowth of endometrium), or other rare thickening, cyst formation and scarring,
Endometrial cancer is rare under the age of 50. estrogen-producing tumors. The diagnosis Pelvic inflammatory disease (PID) most often leading to infertility. Diagnosis is confirmed by
It usually produces irregular periods, abnormal is confirmed by ultrasound scan and biopsy. results from a sexually transmitted disease swabs of the area, ultrasound, and laparoscopy
post-menopausal bleeding, or bleeding after The main treatment is surgery, although (STD) that goes unnoticed for weeks or months. (a keyhole procedure used to examine the
radiation therapy, hormone treatment, or fallopian tubes). PID is treated with antibiotics;
chemotherapy are sometimes needed. partners should also be checked for infection.

Endometrium

Uterus Fallopian tube Inflamed
Enlarging tumor fallopian
Ovary tube

Uterine tumor Inflamed parts Inflamed
In most cases of uterine cancer, the Bacterial infection in the uterus ovary
endometrial cells, which line the inside or fallopian tubes can cause
of the uterus, develop into a tumor that inflammation that blocks the
grows into the uterus. passage of eggs from the ovaries.

472

DISEASES AND DISORDERS

MALE REPRODUCTIVE SYSTEM DISORDERS

The functioning of the male reproductive system involves complex physical and hormonal interactions
between the testes, penis, prostate gland, and seminal vesicles; the pituitary and hypothalamus in the brain;
and the adrenal glands, liver, and other tissues. Disruption in any of these tissues can result in disorders.

HYDROCELE hernia, as part of the bowel can also protrude TESTICULAR CANCER Section through cancer cells
through the passage to the scrotum. The The cells of a malignant teratoma, a cancer of the
A collection of fluid around the testis, hydrocele is usually reabsorbed as the baby The most common cancer in men aged testis, are shown here as three rapidly dividing
a hydrocele may be benign, or it may be grows. If it persists after 12–18 months of age, 15–40, testicular cancer usually causes cancer cells with large, irregular nuclei (pale
a sign of underlying disease that needs then surgery may be needed to drain it and a painless lump within the body of one brown) and green cytoplasm.
further investigation. close the passage. In older men, a hydrocele testis. It is becoming more common.
can develop slowly, often reaching a significant achieve penetration. The simplest causes
Hydrocele is commonly seen in newborn boys. size before a man consults his doctor. There Risk factors for testicular cancer include include fatigue, alcohol, stress, or depression.
It is thought to arise in the fetus as the testes is usually no obvious cause, but occasionally having undescended testes, a family history, This experience can then set up performance
descend from the abdomen into the scrotum the fluid may come from inflammation of the European ethnicity, and, less commonly, being anxieties that perpetuate the problem. Physical
and the passage down which they move then testis due to infection, injury, or malignancy. HIV-positive. There are various types of causes are usually due to poor blood supply, as
fails to close, allowing abdominal fluid to enter An ultrasound scan may be performed to testicular cancer. Half are seminomas, which in peripheral vascular disease, or neurological
the scrotum. There may be an associated aid detection of any underlying problem. arise from the seminiferous tubules (structures disorders, as in multiple sclerosis, or a
Swollen testis Management may involve drawing off the responsible for sperm development). The rest, combination of both, as in advanced or
The fluid of a hydrocele is contained fluid or treatment of underlying disease. mainly teratomas, grow from other cell types uncontrolled diabetes. Treatment includes
within a double-layered membrane and may require more aggressive treatment. counseling and reassurance, treatment of any
partially surrounding the testis but not the Most common in middle-aged and older men, underlying disease, and, for more persistent
epididymis, which can be felt above and epididymal cysts often occur in both testes, Diagnosis is confirmed by ultrasound problems, medical therapies such as drugs.
behind the swelling. and are painless. They can grow to any size but scan and biopsy (removal of cells or tissue
do not need removal unless they become for examination) or testis removal if there is a
Bladder painful or too large. There is a link to genetic strong possibility of cancer. Chemical markers
disorders including cystic fibrosis and in the blood may indicate certain tumor types,
Urethra polycystic kidney disease. A doctor may be but a negative result does not rule out all
Epididymis able to detect them by physical examination: cancers. More than 90 percent of testicular
cysts differ from hydroceles by the fact that a cancers can be cured. Treatment is by surgical
Scrotum doctor can feel above the swelling, and from removal, and then chemotherapy or
Testis testicular cysts because they can be felt as radiation therapy. However, these
Fluid separate from the testis. An ultrasound scan, treatments can cause sterility, so semen
or very rarely a fluid sample from the cyst, may be put into storage, to be used later
EPIDIDYMAL CYSTS confirms the diagnosis. If painful or bulky, for artificial insemination. Regular
cysts may be removed surgically. self-examination reveals most lumps at an
These very common, benign, fluid-filled earlier stage, giving a better outlook.
swellings occur in the upper part of the Epididymal cyst
epididymis, the coiled tube that stores Cancer
sperm from the testis. Ultrasound scan of epididymal cysts
This scan shows three fluid-filled epididymal cysts Tumor of testis
lying within the epididymis at the head of the Testicular tumors of this size are
testis. These develop slowly and are harmless. often painless but are noticeable on
self-examination as a lump or painful
general swelling of the groin or testis.

ERECTION DIFFICULTIES

Difficulty in achieving or maintaining
a penile erection is a common problem
for men, and can be an indicator of
psychological stress or physical disease.

Defined as an inability to achieve or keep an
erection, erection difficulties range from
insufficient hardness to complete inability to

473

MALE REPRODUCTIVE SYSTEM DISORDERS

PROSTATE DISORDERS obstructing the flow of urine through the urethra. The cause is
unknown, but by the age of 70, about 70 percent of men are affected.
A walnut-sized gland at the base of the bladder, surrounding the The prostate can also become infected or inflamed. Cancer may develop
urethra, the prostate secretes an alkaline fluid to protect and nourish from any of the cell types in the gland.
sperm. The most common prostate gland disorder is benign prostatic
hyperplasia (BPH), in which the prostate enlarges with age, sometimes

Bladder Prostate Urethra Enlarged prostate these problems is benign prostatic hyperplasia
(BPH), or noncancerous enlargement of the
Normal prostate Enlarged prostate ENLARGED PROSTATE gland. To confirm diagnosis of BPH, and
The prostate gland surrounds the urethra at the As the prostate enlarges it constricts the urethra, distinguish it from the much rarer prostatic
point where it exits the bladder, and secretes causing a poor, dribbling flow and frequent need There are several possible causes of an cancer, a physical examination of the prostate,
prostatic fluid, which is combined with sperm. to pass urine. Total blockage may require surgery. enlarged prostate, including benign often with an ultrasound scan, biopsy, and PSA
prostatic hyperplasia (BPH), prostatitis, test (see below), is done. Urine flow studies
and benign or cancerous tumors. and cystoscopy (an internal camera inspection
of the bladder) may also be carried out. If the
Most men are unaware of their prostate gland, symptoms affect quality of life, medication
which lies just beneath the bladder, until they may be given to relax the smooth muscle of
reach middle age, when disorders affecting the the prostate and bladder neck, or shrink the
gland are common. Symptoms include an prostate gland, to improve urine flow. Surgery
urgent need to urinate, difficulty passing urine, may be also required to reduce the pressure
poor flow, dribbling, erectile dysfunction, or on the bladder and urethra, or to remove
retention of urine. The most common cause of the gland altogether.

PROSTATITIS hospital but can be treated effectively. Chronic blood for STDs, or by massaging the prostate
bacterial prostatitis is a long-lasting bacterial to obtain samples of prostatic fluid, which is
Inflammation or infection of the prostate infection that can spread to the bladder and tested for infectious organisms. Chronic and
gland, prostatitis can be acute (short- kidneys. In some cases no bacteria are found acute bacterial prostatitis can be successfully
lived) or chronic (long-lasting). but persistent pain occurs. Symptoms include treated with antibiotics, although the condition
fever, chills, and pain in the lower back. can recur. There is no single recommended
The term prostatitis covers several conditions Chronic nonbacterial prostatitis is the most course of treatment for nonbacterial prostatitis.
that have similar symptoms. Acute bacterial common type of prostatitis. It is more difficult
prostatitis is a relatively rare but serious to treat as its cause is unknown. Symptoms Bacteria associated with prostatitis
condition that may require admission to the include pain in the groin and penis, and Escherichia coli bacteria live in the bowel in large
difficulty and pain when urinating. All forms of numbers and are the most common infective
prostatitis are diagnosed by testing urine or cause of acute prostatitis.

PROSTATE CANCER arise from any of the prostate cell types, but spread. Treatments depend on the stage of the
most are adenocarcinomas, developing in the cancer and the age, health, and wishes of the
The second most common cancer in men, gland cells. The diagnosis is confirmed by man, but include removal of the prostate
prostate cancer is rare before the age of physical examination, ultrasound scan, PSA gland, with radiation therapy, chemotherapy,
50, and often grows slowly and silently. test, and biopsy (tissue sample). Bone and liver and hormone therapy to block the effect of
scans or MRI may show how far the cancer has testosterone and thus limit tumor growth.
Prostate cancer often causes few symptoms,
and is often only revealed late on, after the PSA TESTING
cancer has spread. Because it is a cancer of
older men, who may have other health Prostate-specific antigen (PSA) is a protein
problems, it is often not the cause of death. It produced by cells in the prostate that
is more common in men with a family history circulates in the bloodstream. Prostate
and in African-American men. Cancer can cancer or benign prostate conditions cause
higher levels of PSA in the blood, so blood
Prostate gland samples can be used to help test for
prostate problems. Raised blood levels of
Ultrasound scan of cancerous prostate gland PSA, however, can also be due to BPH
Rectal ultrasound scan of the prostate can show (benign prostatic hyperplasia) or prostatitis,
the type of enlargement and give clues to the so further testing may be required. For men
cause, such as tumors or inflammation. with prostate disease, PSA levels may be
monitored to detect any advance in disease
and to plan treatment.

474

DISEASES AND DISORDERS

SEXUALLY TRANSMITTED DISEASES

Most sexually transmitted diseases (STDs) may reduce quality of life and lead to chronic DISEASE PREVENTION
health issues, including pain and infertility. More serious infections, such as HIV and syphilis,
can be fatal. The incidence of all STDs is increasing despite medical advice about prevention. The only certain way to prevent the spread
of STDs is not to have any sexual contact.
CHLAMYDIA pain on intercourse, and irregular vaginal and eyes, called Reiter’s syndrome; this is more Realistically, the most effective prevention
bleeding. Men may have urinary pain, urethral common in men. During pregnancy chlamydia is by practicing safe sex—using a condom
The most common bacterial STD, discharge, or testicular and prostatic can be passed to the baby, causing pneumonia for any sort of sexual contact. This will
chlamydia can affect both men and discomfort. In the long term, damage to the or conjunctivitis at birth. The infection can be prevent most, but not all, infections,
women, causing long-term pain and fallopian tubes in women causes scarring, diagnosed with a urine sample from men and because some STDs can be passed on
reduced fertility. increasing the risk of ectopic pregnancy and a cervical or vaginal swab from women, and is outside the areas covered by condoms.
infertility. The infection can also spread to the treated with antibiotics. Condom use and The risk can be lowered further only by
Chlamydial infection is now thought to affect liver. Both sexes occasionally suffer an tracing sexual contacts both play an important being in a mutually monogamous
1 in 10 sexually active young people and many associated inflammation of the joints, urethra, part in stopping the spread of chlamydia. relationship with your partner.
older men and women. The bacterium that
causes the infection, Chlamydia trachomatis, is Cell infected with Multicolored condoms
carried in semen and vaginal fluids and passed chlamydia Most condoms are made of latex: this can
on during sexual contact. It lives in the cells of The bacterium dissolve on contact with some toiletries, but
the cervix, urethra (the tube leading from the multiplies over 48 water- and silicone-based lubricants are safe
bladder to outside the body), and rectum, or in hours before the cell for use with condoms.
the throat, and, rarely, in the eyes, where it can bursts, releasing new
cause conjunctivitis. organisms to spread to
surrounding cells.
Many of those infected report no or only
mild symptoms. As a result, the infection may
go undetected for weeks or months, causing
inflammation that can reduce both partners’
fertility. If symptoms do occur, women tend to
notice a slight vaginal discharge, pelvic pain or

GONORRHEA months later. Women tend to experience URETHRITIS in condoms. The symptoms depend on the
recurrent episodes of abdominal pain, irregular cause but may include discharge, difficulty or
A bacterial infection mostly confined to bleeding, and heavy periods; men may notice Known as nonspecific urethritis or NSU, pain when urinating, frequent urination, and
the genital tract, gonorrhea can cause testicular or prostatic pain. The bacterium can inflammation of the urethra can be due itchiness or irritation at the end of the urethra.
permanent damage and reduced fertility live in the cervix, urethra, rectum, and throat, to infection or a variety of other causes. Left untreated, the inflammation may spread,
in both men and women. and may spread through the blood to other causing testicular and prostatic pain in men, or
areas such as the joints, causing arthritis and NSU can occur in both men and women. (with chlamydia) pelvic inflammatory disease
The bacterium Neisseria gonorrhoeae is passed tenosynovitis, and a rash. During vaginal (see p. 471) in women. Urine tests and swabs
during sexual contact. Infection may cause delivery, an infected mother may pass it to her Infective causes include STDs such as herpes, help identify infection, and drugs may be used
genital pain, inflammation, a green or yellow baby, causing eye and other infections. to kill infective organisms. Prevention may
discharge from the penis or vagina, and pain chlamydia, and Trichomonas vaginalis, as well include using only nonlatex condoms.
on urination in the next few days or even many Gonorrhea can be detected by a urine
sample, or penile, cervical, throat, or eye as nonsexually transmitted infections
swabs, and is usually easy to treat with
antibiotics. Left untreated, however, chronic such as thrush (candida)
inflammation scars women’s fallopian tubes,
reducing fertility and increasing the risk of and bacterial vaginosis.
ectopic pregnancy, because the egg cannot
pass down the tube properly. Chronic infection The symptoms of NSU
also puts future sexual partners at risk.
Condom use and tracing sexual contacts can may also occur Urethra
help prevent the spread of gonorrhea.
without infection,

possibly due to a Epididymis
chemical sensitivity

to soap, spermicide,

antiseptics, or latex Testis

Gonorrhea bacterium Symptoms of NSU
Microscopic view of Neisseria gonorrhoea, the Urethritis causes inflammation of the
bacterium that causes gonorrhea, which can often urethra. If left untreated it can spread
be quickly identified under the microscope. to the testis and epididymis, which
can become swollen and inflamed.

475

SEXUALLY TRANSMITTED DISEASES

GENITAL WARTS and mucous membranes, and is spread during Anal warts
genital contact of any sort. In many people, Also called condyloma acuminata, genital warts
Some strains of human papillomavirus there is no sign of infection and the virus is not are highly contagious. These small, cauliflower-
(HPV) can cause fleshy growths, or warts, carried for long. Sufferers may also be unaware shaped lesions may cause itching, bleeding, and
in the genital and anal areas. that they carry the virus because warts can take discharge, or may not be noticed.
weeks, months, or years to develop. They show
There are over 100 strains of HPV, although as small, painless, fleshy lumps in the genital or
not all cause genital warts. Strain types 6 and anal area, internally or externally. Genital warts
11 are responsible for 90 percent of genital do not have serious consequences and most
warts. HPV infects the epidermis (skin surface) will eventually disappear, although this may
take months or years, during which time they
Human papillomavirus remain infectious. Treatment using creams,
The virus that causes genital warts can enter the freezing, electrocautery (removing the wart by
body through the skin around the genital area, so burning it with a low-voltage electrical probe),
condom use may not be fully protective. or laser can clear them more quickly; in the
meantime, condom use is advised to help
prevent spread of the infection.

SYPHILIS The bacterium that causes syphilis is passed on with a flulike illness, a non-itchy rash, and GENITAL HERPES
during intercourse, or by skin contact with a sometimes wartlike patches on the skin. The
Once rife and untreatable until the syphilitic sore or rash. A painless sore called a final stage, tertiary syphilis, may take years to A blistering, painful rash caused by
development of antibiotics, this infection chancre usually develops on the genitals, but develop. It affects parts such as the blood herpes simplex viruses HSV1 and HSV2,
is now increasing again. Left untreated it can occur on the fingers, buttocks, or in the vessels, kidneys, heart, brain, and eyes, and can this infection may recur repeatedly.
it can affect many parts of the body. mouth. The chancre may take up to six weeks cause mental disorder and death. The first and
to heal, and may go unnoticed. The next stage, second stages can be treated by antibiotics, The herpes simplex viruses enter the body via
HIV AND AIDS secondary syphilis, occurs several weeks later, but the damage in the third stage is permanent. close contact with skin or moist membranes.
Both HSV1 and HSV2 can cause genital and
Infection with human immunodeficiency which are a vital part of the immune system’s Kaposi’s sarcoma skin lesion oral lesions, either within days of infection or
virus (HIV) is lifelong and can lead to defense against infection. As the disease These tumors start as small, painless, flat areas weeks or months later. These small, painful
acquired immunodeficiency syndrome progresses, fever, night sweats, diarrhea, or lumps, colored brown, red, blue, and purple, sores can last for several weeks before
(AIDS), a life-threatening condition. weight loss, swollen glands, and recurrent which look like bruises and grow until they merge. subsiding. Other symptoms include flulike
infections may occur. In its late or advanced illness, fatigue, aches, pain on urination, and
HIV may be passed by contact with bodily fluids stage, known as AIDS, the CD4 count drops candida, and cytomegalovirus, and a skin swollen glands. Many people have only a mild,
including blood, semen, vaginal fluids, and very low, and a variety of immune system- cancer called Kaposi’s sarcoma. single infection, but some experience regular
breast milk. (The level of HIV in urine and saliva related conditions develop. These include relapses. These are often triggered by other
is thought to be too low to be infectious.) opportunistic infections caused by organisms Those with HIV can be regularly monitored illnesses and, although usually less severe each
Initially there may be a short flulike illness that live harmlessly in healthy people, such and have opportunistic infections treated time, can be debilitating. The virus can be
(called sero-conversion illness), mouth ulcers, as Pneumocystis pneumonia, promptly. People with HIV remain infectious passed even by people with no active lesions.
or rash for up to 4 weeks, or no throughout their life, but can avoid passing it on Pregnant women with active sores can pass
symptoms at all. The virus then Infected CD4+ by practicing safe sex using condoms. Infected the virus to their baby during pregnancy or in
multiplies in the body over several lymphocyte mothers, who can pass HIV to their baby before childbirth. Attacks of herpes may be treated
years, damaging the immune or during birth, and by breastfeeding, may be with antiviral medication; this is most effective
system. This damage can be Mature HIV particle offered antiretroviral drugs and cesarian delivery. as soon as symptoms start.
measured by the reduction in the The only way to positively diagnose HIV is
number of CD4 (T-helper) cells, an antibody blood test. This can take up to 3 Herpes simplex lesion
months to become positive after HIV exposure. The lesions of genital herpes are typically
painful irregular blisters, which break down to
Although there is no vaccine or cure for HIV, form ulcers, with a raised, reddish outer edge
“HAART” (Highly Active Antiretroviral Therapy) and weeping inner area.
has changed AIDS from a rapidly fatal disease to
a chronic condition with many complications,
most of which can be managed.

Mature HIV particle and infected CD4+ lymphocyte
CD4 cells are lymphocytes (white blood cells) with CD4 protein
molecules on their surface, usually responsible for starting the body’s
response to invading viruses. HIV binds to CD4 in order to enter the
cell, damaging the cell in the process.

476

DISEASES AND DISORDERS

INFERTILITY

More than 1 in 10 couples experience infertility—difficulty conceiving a baby. Most male
problems center on poor sperm function, but for women fertility depends on a complex
interaction between hormonal activity, egg production, and the ability to carry a fetus.

OVULATION PROBLEMS process is influenced by many hormones, contraceptives, being under- or overweight,
including the gonadotropins, follicle- excessive exercise, and stress. Tests are used to
Ovulation takes place when an egg is stimulating hormone (FSH) and luteinizing determine hormone levels and find out if
released and is ready to be fertilized. hormone (LH), estrogen, and progesterone. ovulation is taking place. Treatment may
Eggs released intermittently or not at all Around day 14, the dominant follicle ruptures, include the use of gonadotropin-releasing
can cause problems with conception. and the egg is released into the fallopian tube hormones, progesterone, and clomiphene to
and travels to the uterus. The control of this stimulate ovulation.
During the normal 28-day menstrual cycle, process relies on hormonal interaction
many ova (eggs) develop, each in a follicle, in between the hypothalamus and pituitary gland Cystic follicles
the ovary. Usually one egg is released every in the brain, and the ovaries. Factors that can
month; the other follicles and eggs wither. The disrupt this process include pituitary and Polycystic ovary
thyroid gland disorders, polycystic ovary A common condition including multiple ovarian
syndrome, long-term use of oral cysts and abnormal hormone levels, polycystic
ovary syndrome (PCOS) can cause infertility.

Ovary UTERUS ABNORMALITIES problem arises, either during development or, PROBLEMS WITH EGG
more rarely, as a result of scarring, if the hymen, QUALITY
Fibroid growing into A variety of abnormalities, from defects a thin membrane that blocks the entrance to
lining of uterus in development to growths in the uterus, the vagina, is unbroken. This prevents the flow Egg quantity and quality both decline
can cause problems with fertilization and of menstrual fluid, causing a swelling to grow as significantly with age, particularly from
Vagina the ability to carry a fetus. blood collects every month. It also prevents the mid-30s.
penetration during intercourse, so fertilization
Fibroid As a female fetus develops, the uterus and of the egg cannot occur. Poor-quality eggs may not be fertilized, or may
Benign (noncancerous) smooth muscle tumors vagina form from two halves that fuse together. be fertilized but not develop properly to achieve
of the uterus, fibroids can grow large enough Incomplete fusion can cause abnormalities Some abnormalities can easily be remedied implantation in the uterus. If implantation does
to disturb the interior of the uterus, possibly such as a doubling of the uterus (bicornuate by surgery—for example, removal of a vaginal occur, there is a higher than average chance of
interfering with egg implantation. uterus) or the cervix, or a septum (membrane) septum. Other deformities may need surgical miscarriage. Egg quality depends on several
dividing the vagina. These problems may, in reconstruction. Some abnormalities develop factors including normal chromosomes, the
some cases, reduce fertility in adult women. in adulthood. These include tumors and a ability to combine the chromosomes with those
Some problems only become apparent in early tightening of the cervix, which can occur after a in the sperm, and stored energy to enable cell
pregnancy if an abnormally shaped uterus cone biopsy (used to investigate precancerous splitting after fertilization. This energy is held in
prevents proper fetal development. Late cervical changes). The most common tumors particles called mitochondria, but levels drop
miscarriage and premature or difficult labor that affect uterine shape are fibroids and as the eggs age. Smoking is one of the external
are more likely problems and may arise due to cervical or endometrial polyps. The risk of factors known to reduce egg quality. This
poor implantation of the egg or restricted fertility problems increases with the size of condition is hard to treat, although IVF can
growth of the fetus and uterus. A minor these growths; it also varies with their position be used to select good eggs or embryos.
within the uterus. Most of these tumors are
noncancerous, but they may need to be
removed to improve the chance of conception.

BLOCKED FALLOPIAN TUBES If the egg cannot pass down the tube, the sperm “ectopic” pregnancies, the embryo’s growth
will not reach it and conception will not occur. may result in the tube bursting, miscarriage,
Damage to the fallopian tubes can affect Alternatively, the egg may be fertilized inside the hemorrhage, and serious risk to the mother.
egg transport and embryo implantation, tube and the embryo will grow there. In these Surgery may be performed to open the tubes,
or even prevent fertilization altogether. but often IVF, bypassing the need for healthy
tubes, may offer a better chance of pregnancy. Ovary Blocked
Endometriosis, pelvic inflammatory disease fallopian
(PID), adhesions from abdominal surgery, and Blocked tube
genetic disorders can interfere with the function entrance
of the fallopian tubes. These conditions weaken to fallopian tube Uterus
the action of the hairs lining the fallopian tube,
which normally brush the egg along its length. X-ray showing blocked tubes Fallopian tube damage
Dye can be injected through the cervix in a Inflammation, for example in
procedure called hysterosalpinography. This PID, can cause tubal damage
can reveal a blockage in the tubes. or blockage.

477

INFERTILITY

CERVICAL PROBLEMS previous injury or surgery), can Ovary Uterus PROBLEMS WITH SPERM
cause miscarriage. Functional QUALITY AND PRODUCTION
The cervix is the gateway to the uterus, problems include cervical mucus Cervix
through which sperm pass to fertilize the that stops sperm by being too thick Mucus Male factors account for about one half
egg, so any defects can reduce fertility or acidic, or by containing antibodies to of infertility: in particular, problems with
and pose a risk of miscarriage. sperm. Women may be treated with IVF. sperm numbers, motility, abnormal
shapes, and antibodies to sperm.
Cervical cells secrete mucus, which underges Mucus Antibody
hormonally influenced cyclical changes to aid Testing for problems relies on semen analysis
fertilization and then protect the uterus. At Opening Cervix in the laboratory. Semen volume and pH,
mid-cycle the mucus becomes clearer, thinner, of cervix sperm numbers and concentration, motility
and more copious, making it easier for sperm Antibodies to sperm (movement), morphology (shape), and the
to flow up into the uterus. Later, it thickens to Sperm These proteins, produced by presence of antibodies (immune system
provide a barrier to infection, thus protecting either the woman or the man proteins wrongly targeting the man’s own sperm
the fetus. Cervical problems can be structural himself, attack sperm in the as invading organisms) are all assessed. A
or functional. Any congenital (present from cervical mucus or the semen, postcoital test may also be done, to test the
birth) abnormalities or polyps, fibroids (see interfering with their movement so sperm’s ability to swim in the woman’s cervical
p.470), or cysts in the cervix may block the that they fail to fuse with the egg. mucus. Factors affecting sperm quality and
passage of sperm. During pregnancy, cervical quantity include smoking, alcohol, chemical
incompetence, in which the cervical entrance PROBLEMS WITH PASSAGE urethra into the woman’s vagina, where fewer exposure at work, medicines and drug abuse,
(os) cannot close fully (usually as a result of OF SPERM than 100,000 manage to enter the uterus previous disease such as rubella and STDs, and
through the cervix. By the time they get to the high testicular temperature. In men with poor
Narrowed Fertility may be affected by a blockage of egg, somewhere in the fallopian tubes, there sperm counts, the use of ICSI (intracytoplasmic
lumen of vas the vas deferens, which transports semen may only be 200 left. Even if all else is normal, sperm injection), where only a few sperm are
from the testis to the penis, or by the the majority are lost through wastage as they needed to be injected into an egg, gives a
deferens journey of the sperm to the egg. swim the wrong way, fail to keep moving, or much better chance of fertilizing the egg.
simply become exhausted. In addition, factors
Epididymis The sperm, which carry the man’s genetic such as testicular disease, retrograde ejaculation Deformed sperm
material, are made in each testis and stored in (when semen is ejaculated, but backward), Deformed sperm exist in every ejaculate: semen
Inflamed vas deferens two chambers, called an epididymis. During difficulty of sperm getting through the cervical analysis defines a normal sample as having at least
Injury or infection can inflame the epididymis and release (ejaculation), the sperm are combined mucus, uterine abnormalities, or poor fallopian 15 percent normal-shaped sperm.
the tube leading from it, the vas deferens, causing with seminal fluid from the prostate gland to tube function all reduce the chance that the
blockage that stops the release of sperm. form semen. This is released from the man’s sperm will meet the egg. These problems are
hard to treat, but IVF offers an opportunity to
IN-VITRO FERTILIZATION bypass them.

Commonly abbreviated IVF, in-vitro Follicles Ovary Uterus Fluid EJACULATION PROBLEMS
fertilization is a method of artificially
fertilizing an egg outside the body, culturing Hollow Ultrasound- Hollow Sperm delivery occurs by ejaculation: a
the embryo in the laboratory, and replacing needle guided probe tube contraction of the vas deferens, seminal
it to grow inside the uterus. IVF is used for vesicles, ejaculatory ducts, and the
most types of infertility apart from uterine 1 Egg collection 2 Introduction of fertilized eggs muscles around the urethra.
anatomical abnormalities. It starts with the One eggs has reached a certain maturity, Three or four of the cultured embryos are
woman having hormone injections to they are retrieved using a needle and probe, and inserted via a tube through the cervix into the Ejaculation problems range from complete
stimulate her ovaries to produce large incubated with sperm in the test tube. uterine cavity for implantation to take place. failure to retrograde ejaculation, in which the
numbers of eggs which are harvested. semen passes back into the bladder rather
Donor eggs or sperm may also be used. Egg than down the urethra. These problems can
result from many muscular and neurological
The eggs are incubated with the sperm Microneedle disorders, such as stroke, spinal injury, or
to achieve fertilization, although ICSI (the diabetes, and can also occur following prostate
direct injection of a sperm into the egg) is Sperm injection or bladder surgery. Investigation includes
used in around half of IVF treatment cycles. In intracytoplasmic injection (ICSI), semen analysis and bladder function studies.
The fertilized eggs are cultured for 5–7 days, sperm is injected directly into eggs Intracytoplasmic insemination (see left) offers
and then implanted into the uterus. In some to achieve fertilization. hope when ejaculatory failure is not treatable.
cases, assisted hatching is done, in which
the shell of the embryo at the eight-cell
stage is digested by acid to improve the
chances of implantation and pregnancy.

478

DISEASES AND DISORDERS

DISORDERS OF PREGNANCY AND LABOR

Normal pregnancy lasts about 38 weeks from conception, or 40 weeks from the last menstrual
period. Pregnancy and labor (the process of delivering a baby) are usually straightforward.
However, problems can affect the mother or baby at any stage.

ECTOPIC PREGNANCY some cases, however, it implants outside the BLEEDING IN EARLY implantation bleeding—and may be mistaken
uterus—most commonly, in the fallopian tube. PREGNANCY for a very light menstrual period. Another
An ectopic pregnancy is one in which the Most ectopic pregnancies end in miscarriage. If common cause is bleeding from the cervix
embryo begins to grow outside the the embryo continues to grow, after 6 to 8 Affecting at least 1 in 8 pregnant women, (neck of the uterus) due to the development
uterus, usually in the fallopian tubes. weeks it may cause the tube to rupture, resulting bleeding may occur due to miscarriage of an erosion (a raw, red area that bleeds easily)
in internal bleeding, shock, and pain, a medical or ectopic pregnancy, but in most cases it under the influence of pregnancy hormones.
Normally, an egg is fertilized and grows into an emergency that must be treated with surgery. has a less serious cause. Bleeding may also originate from the edge
embryo in the fallopian tube and then Ectopic pregnancy is more likely if the fallopian of the growing placenta or be caused by an
implants in the uterine lining. In tubes have been damaged due to infection, Bleeding in the first 4 weeks is sometimes ectopic pregnancy (see left). Most episodes of
particularly chlamydia (see p.474), or surgery. thought to result from the embryo implanting bleeding in early pregnancy do not lead to loss
itself into the wall of the uterus—so-called of that pregnancy. However, heavier bleeding,
Fallopian with passage of clots or with cramping pain, is
tube more likely to mean the pregnancy is failing.

Embryo embedded into
fallopian tube lining

Amniotic fluid Placenta

Uterus Ovary MISCARRIAGE Umbilical
cord
Implanted embryo Fallopian tube Around 1 in 4 pregnancies end in
Fertilization occurs when egg and sperm meet, miscarriage—the natural loss of a baby, Fetus
often while the egg is still in the fallopian tube. usually before the 24th week. Cervix
If the egg fails to complete its journey, ectopic Vaginal
(“out-of-place”) implantation can occur. Pregnancies can fail for a variety of reasons. The bleeding
embryo may not implant properly, or the fusion Threatened miscarriage
PREECLAMPSIA The disorder is thought to be caused by the of sperm and egg goes slightly wrong so the In this condition, vaginal bleeding occurs but the
mother’s immune system reacting to substances fertilized egg cannot survive. Occasionally a cervix stays closed and the fetus is alive. In many
This condition is typified by high blood released from the placenta. The main symptoms fetus fails to grow (a “missed” miscarriage), and cases the pregnancy continues to a successful
pressure and edema (tissue swelling); are high blood pressure, edema (fluid buildup this may not be discovered until the first scan. birth, but some may develop into full miscarriage.
it can be mild or life-threatening. in the tissues), and protein leakage from the Miscarriage can also be caused by a problem in
kidneys. In severe cases it can lead to eclampsia, the mother, such as weakness in the cervix (neck
Preeclampsia can arise any time from 20 weeks with seizures and possible stroke in the mother, of the uterus), infection, or an illness such as
of pregnancy to six weeks after the birth. It is and threat to her life and that of her baby. diabetes. Often there is no obvious cause. The
more common in first and twin pregnancies. Delivery is the only cure, and women with most common symptoms are bleeding and
preeclampsia may have their baby induced pain. Many affected women do not even know
before the pregnancy reaches its full term. they were pregnant because the miscarriage
occurs at or before the time the period was due.
Later miscarriages tend to be more painful and
distressing, with greater blood loss and more
need for medical attention.

PLACENTA PROBLEMS uterus grows rapidly at this stage. In some cases Placenta previa Placental abruption
the growing placenta moves upward and the In some cases, the As the placenta shears off,
Some complications in later pregnancy problem settles. In severe placenta previa (when placenta lies low in the blood escapes through
can be due to problems with the placenta, the placenta covers the opening of the cervix), uterus and may cover the vagina or collects
the organ that keeps the fetus alive. heavy bleeding may threaten the life of mother the cervix. behind the placenta.
and baby. If the placenta is very low, normal
In placenta previa, the placenta lies too low in birth may not be possible. Placental abruption is Amniotic fluid Placenta
the uterus, near or over the cervix (neck of the the separation of the placenta from the uterus
uterus). This can cause painless, bright red before birth. It can cause vaginal bleeding, or Uterus Blood between
bleeding, often at about 29 to 30 weeks—the trapped blood may build up behind the uterus and
placenta. Abruption can cause severe pain in Umbilical cord placenta
the mother and risk to the baby.
Placenta Uterus

Cervix

479

DISORDERS OF PREGNANCY AND LABOR

PROBLEMS WITH GROWTH such as smoking or alcohol use by the mother, with a reduction in protective fluid around the ABNORMAL PRESENTATON
AND DEVELOPMENT thrombophilia (a disorder that causes a higher baby. A fetus whose growth has been severely
risk of blood clots), and preeclampsia. Problems restricted is at risk of dying in the uterus, likely The baby has to settle into a particular
The failure of a baby to grow properly in in the fetus include infections such as rubella, to have a low birth weight with an increased position ready for birth. Any deviation is
the uterus is called intrauterine growth blood abnormalities, genetic abnormalities risk of distress during labor, and liable to known as an abnormal presentation, and
retardation; this problem can place a that affect growth, kidney problems, Rh disease complications after birth. Intrauterine growth this can make the birth more difficult.
baby at risk both before and after birth. (a mismatch between the mother’s blood type retardation is usually identified in pregnancy,
and that of the fetus), and being one of twins when doctors measure the growth of the Ideally, babies lie with their face toward the
Growth retardation is often caused by a lack of or more. The condition is also often associated uterus. Ultrasound scans may be done to mother’s back and their head down, over the
oxygen or nourishment reaching the fetus. It cervix, ready to push against it as the uterus
can result from a variety of factors affecting effective in opening the cervix. During the first measure the fetus and assess contracts. In an abnormal presentation the
the mother, the fetus, or the placenta (which and second stages, every time the uterus blood flow through the baby may be in a “breech” presentation, lying
nourishes the baby in the uterus). squeezes, the baby’s blood supply is briefly placenta. If there are signs with its bottom first, or it may lie head down
reduced. Over time, especially with prolonged that the fetus is distressed, or but too high in the pelvis to push on the
Maternal factors include anemia, labor, the baby will grow tired and stressed, its growth seems to be cervix. Occasionally babies lie crosswise, or at
which reduces the baby’s oxygen supply; with lowered oxygen levels and increased coming to a halt, the birth an oblique angle, with an arm over the cervix.
preeclampsia, which can reduce blood flow to blood acidity. Small or premature babies, may be brought forward.
the placenta; infections such as rubella, which A variety of maneuvers are used to deliver
pass to the fetus and affect development; and Growth monitoring babies who present abnormally, but these can
a prolonged pregnancy, when the placenta Ultrasound provides an image cause trauma to the mother or detachment of
becomes less efficient and growth slows. of the fetus and can be used to the placenta. It is possible to turn the baby and
Placental causes of growth retardation include monitor growth, check that the then break the waters so that the head comes
anything that reduces placental blood flow, baby is developing normally, down against the cervix in a controlled way,
and measure blood flow in the but this can be risky because the baby may lie
PROBLEMS DURING LABOR placental vessels. abnormally for a reason (such as the placenta
being in the way or the mother’s pelvis being
An overly long or difficult labor can be babies of anemic mothers, or babies who have too small). If the baby is lying longitudinally,
stressful, exhausting, and risky for both preexisting problems are more vulnerable. If normal delivery may be possible. If the
mother and baby. the contractions are too weak or the baby is mother’s pelvis is too small to let the baby
showing signs of distress, the mother may be out, or the placenta is in the way, cesarean
given artificial hormones to strengthen the section (see left) is the only option.
contractions, or an assisted delivery (see below)
may be carried out.

There are three stages of normal labor. In ASSISTED DELIVERY
the first stage, the muscular walls of the uterus
begin to contract and the cervix (neck of the If the mother cannot deliver the baby Incision PRETERM LABOR
uterus) gradually dilates (opens) to a width normally or if the birth needs to be speeded
of about 4 in (10 cm). In the second stage, the up, an assisted delivery may be carried out. Cesarean section If labor begins before the 37th week of
baby is born. The third stage involves delivery Procedures include the use of forceps or In the procedure, a cut is made into the lower pregnancy, it is defined as pre-term; if it
of the placenta. Ventouse, or cesarean section. A Ventouse part of the uterus, and the baby is removed via occurs very early, the baby may suffer
device is a cap fitted against the baby’s head this incision. It is used if a vaginal delivery would health problems or even die.
During labor the uterus contractions, and used to help pull the baby gently as the be too difficult or unsafe for the mother or baby.
dilation of the cervix, and the baby’s heartbeat mother pushes. Forceps are instruments There are many possible causes of pre-term
are monitored to detect any problems. If the that fit around the baby’s head; these also Uterus labor, including abnormalities in the fetus, the
first stage takes too long and the cervix opens help pull the baby as the mother pushes. placenta, or the mother. The risks are greater
too slowly, the mother can be weakened by Cesarean section is surgical delivery of the for the baby, who may be born before the
pain and exhaustion and this can make the baby through the abdomen. The mother lungs (and many other organs) are fully
birth more difficult. A long first stage is more may be given a general anesthetic, or she mature. If labor begins too soon, drugs may
common in first-time mothers, whose may have a spinal or epidural anesthetic, be given to delay or inhibit contractions.
contractions can be dysfunctional and less which numbs the body below the waist. Labor may be temporarily halted or delayed
long enough for corticosteroids to be given to
Tube to suction help the baby’s lungs mature, so it is less likely
pump to suffer respiratory problems.

Uterus Premature baby
Babies have survived outside the uterus at around
Fetus Fetus 22 weeks, although the risks of lung, brain, and
Forceps eye damage are extremely high.

Fetal monitoring Vacuum suction delivery Forceps delivery
Two sensors are fitted to the mother’s abdomen A Ventouse device consists of a cap held Spoon-shaped obstetric forceps are carefully
to record uterine contractions and fetal heart rate. onto the baby’s head by vacuum suction. placed around the baby’s head. As the mother
Fetal distress may show as sustained rapid beats The baby may have a swelling on the head pushes, the doctor pulls on the forceps until
or as prolonged drops in the heart rate. afterward, but this soon disappears. the baby’s head reaches the vagina.

480

DISEASES AND DISORDERS

ENDOCRINE DISORDERS

The endocrine system is made up of glands and tissues that secrete hormones into the
bloodstream to regulate the function of other organs and body systems. Disorders of
any gland can affect many other glands and disrupt one or more body systems.

TYPE 1 DIABETES The cause of type 1 diabetes is unclear, but it Type 1 diabetes cannot be cured, but it can Injecting insulin
may be an abnormal reaction by the body’s be managed by lifelong treatment with insulin Replacement insulin has to be given, as injections
In this form of diabetes insulin-producing immune system to cells in its own pancreas, to regulate blood sugar levels. The person will or via a pump, several times a day to control sugar
cells in the pancreas are damaged and triggered by a virus or other infection, and be counseled on healthy diet, exercise, and metabolism. Other methods, such as inhaled and
produce little or no insulin, so the body usually occurring in young adult life. As a possible complications (see opposite). He or oral insulin, are currently being developed.
cannot process glucose properly. result, insulin production is reduced or absent. she will be advised to minimize factors that
The starving cells try to get energy from fat increase the risk of cardiovascular disease
The body takes in glucose from food, uses it to cells, disrupting the normal metabolism (the (a major risk with diabetes), such as high
produce energy, and stores any surplus in the chemical reactions that keep the body cholesterol levels, high blood pressure, and
liver and muscles. The levels of glucose in the functioning) and eventually a condition called unhealthy lifestyle habits including overeating,
bloodstream (blood sugar levels) are regulated ketoacidosis, which leads to coma and death. smoking, and alcohol use.
by a hormone, insulin, that is produced in
the pancreas in response to food intake. Insulin Normal beta cell function Signal passes to cell Damaged or
maintains a steady blood sugar level by helping Blood sugar is regulated by beta cells, in groups nucleus, triggering destroyed beta
body cells absorb glucose. If too little insulin is called islets of Langerhans, in the pancreas. These transporters cells
produced, or cells do not take in enough cells secrete the hormones insulin, c-peptide, and
glucose, blood sugar levels become too high, amylin during and after eating. Beta cells
which leads to diabetes mellitus. There are three (insulin-
main types of diabetes: type 1; type 2; and producing cells)
gestational diabetes (see opposite).
Insulin No insulin is
Without insulin, cells cannot absorb secreted into secreted into
glucose. Instead, glucose builds up in the capillaries (tiny capillaries
blood, and blood sugar levels gradually blood vessels)
increase, causing symptoms such as increased
thirst, urinating more than normal, nausea, Damaged beta cells
fatigue, weight loss, blurring of vision, and When the beta cells are damaged, by infection,
recurrent infections. trauma, or aging, the secretion of hormones such
as insulin is reduced and the body’s control of
Diabetes is diagnosed by testing the urine blood sugar is impaired.
for sugar and ketones (an acidic by-product
of fat breakdown) and blood tests, which show
high sugar levels as well as a variety of other
chemical changes that occur as the body tries
to cope with the metabolic disturbance.

BLOOD SUGAR REGULATION

The blood sugar must be kept within a and stimulates fat synthesis from glucose in Pancreas Islet of Langerhans
narrow range, so that cells have enough the liver and adipose (fat) cells. Conversely, These areas of tissue in
glucose but levels do not become too high when blood sugar falls, such as between the pancreas contain five
and thus toxic. The two main hormones meals or during exercise, low sugar types of endocrine cells.
involved in glucose regulation are insulin levels stimulate another group of The islets of Langerhans
and glucagon, both produced by cells in the pancreatic cells, the alpha are responsible for the
islets of Langerhans, inside the pancreas. cells, to secrete glucagon. production of hormones
After food is eaten, high blood glucose This triggers the liver and such as insulin, glucagon,
levels and the release of gut hormones muscle cells to release and somatostatin, all of
called incretins, stimulate the beta cells in previously stored glucose, which are involved in
the islets of Langerhans to produce insulin. induces liver and muscle blood sugar regulation.
cells to make glucose from
This hormone triggers most of the body other dietary elements, and Beta cell produces Alpha cell produces
cells to increase glucose uptake from the increases the breakdown of insulin glucagon
blood; stimulates cells to use more glucose fats to fatty acids and glycerol
as energy; stimulates the liver and muscle for use as energy in cells.
cells to store excess glucose as glycogen;

481

ENDOCRINE DISORDERS

TYPE 2 DIABETES do not take in enough glucose, the glucose first, but high sugar levels may cause symptoms lifestyle changes such as adopting a healthy
level in the blood becomes too high, which such as fatigue, thirst, and recurrent minor diet, doing regular exercise, and losing weight.
In this condition the pancreas secretes leads to diabetes mellitus. infections. If the diabetes is left untreated or Patients are also taught how to monitor their
insulin but the body cells do not respond poorly controlled, the chronic excess of glucose own blood sugar levels. However, as the
to it as a trigger to take in glucose, so There are several types of diabetes; in can damage the blood vessels supplying organs disease progresses, drugs may be needed to
blood sugar levels remain too high. type 2, the disorder results from a combination and tissues throughout the body, resulting in reduce blood sugar levels. Medications may
of decreased insulin secretion, reduced numbers retinal damage, vision loss, kidney failure, and help the pancreas make more insulin or make
Body cells obtain energy by taking in glucose, of beta cells in the pancreas, and increased nerve damage; it can also increase the risk of better use of what is already there, or make
which is released from food during digestion resistance of cells to the effects of insulin. cardiovascular diseases such as stroke, heart the body cells more sensitive to insulin. Some
and then carried in the bloodstream to all the Genetics may play a role, but type 2 diabetes attack, and peripheral vascular disease (disorders patients eventually need insulin therapy
tissues. Normally, insulin, a hormone secreted is also strongly linked to obesity, especially in affecting blood vessels in the legs and feet). (regular injections of insulin). In addition, it is
by cells in the pancreas, helps cells absorb older people. The rapidly increasing incidence necessary to control factors such as high blood
glucose. If too little insulin is produced, or cells in most countries is thought to relate to the Type 2 diabetes is diagnosed using blood pressure and high cholesterol to prevent
rise in weight problems and lack of exercise, and urine tests to detect the excess glucose. diabetes-induced damage to the kidneys, eyes,
resulting in fat storage, especially in the Treatment involves regulating blood sugar nerves, and peripheral blood vessels.
abdomen. The disease may go unnoticed at levels. At first, this may involve simply making

Insulin Glucose binds Glucose Insulin Transporter Glucose
to transporters drawn into inactive remains in
Insulin binds center of cell Cell receptors do bloodstream
to receptor, not allow insulin
“unlocking” cell to bind to them

Nucleus

Normal receptors Malfunctioning Diabetic retinopathy
Insulin binds with receptors Diabetes damages the small blood vessels of
receptors on a cell to allow In type 2 diabetes, the the eye through a variety of problems, such as
glucose to enter the cell. cell membrane receptors hemorrhages, swelling, and fatty deposits,
This triggers transporters are resistant to insulin impairing the light-sensitive cells of the retina.
within the cell to draw attachment or signals
glucose inside. and thus take in too little
glucose from the blood.

OBESITY 100

A growing problem worldwide, obesity can (BMI), or more accurately, by measuring the Overweight
increase the risk of many diseases, including waist to determine the extent of abdominal 75 BMI over 25
diabetes, heart disease, high blood pressure, fat: waist measurements of more than 40 in
arthritis, asthma, infertility, gynecological (102 cm) for men or 35 in (88 cm) for women WEIGHT IN KG 50 Ideal range
disorders, and cancers, such as those of the can indicate excess central abdominal fat and BMI between
breast and colon. The mechanisms by which an increased risk of disorders such as diabetes. 18.5 and 24.9
excess weight increases these risks will vary
but it is known that body fat, especially fat Body mass index 25 Underweight
that is located centrally in the abdomen, The body mass index is found by dividing weight BMI less than 18.5
is hormonally active tissue that can have in kilograms by height in meters squared. A BMI
an inflammatory effect on other tissues. of 18.5 to 24.9 is usually taken to be healthy, but 0 150 160 170 180 190 200
Obesity is defined by the body mass index BMI can be distorted by age and muscle mass. 140 HEIGHT IN CM

GESTATIONAL DIABETES Symptoms include thirst, fatigue, and excessive Tests for diabetes
urine production. If left untreated, there are The development of
The hormonal changes that occur during increased risks of the fetus growing too large, diabetes is relatively
pregnancy can cause a form of diabetes congenital heart malformations, miscarriage, common in pregnancy,
called gestational diabetes, which can stillbirth, or abnormal labor. so pregnant women
pose a threat to both mother and baby. routinely have their
The mother’s or newborn baby’s life may urine dip-tested for
Some pregnancy hormones can counteract the be in danger. Treatment involves controlling sugar; if the test is
effects of insulin, which normally controls blood sugar levels; the woman may receive positive, blood tests
blood sugar levels, so sugar levels become too advice about dietary control and moderate may be done to
high. Gestational diabetes is more common in exercise and, if needed, insulin. The fetus will confirm the diagnosis.
overweight women and in those with a family be monitored by ultrasound. After delivery,
history or personal history of this condition. most women’s blood sugar levels rapidly return
to normal, but for a few this is the start of
lifelong diabetes. The risk of recurrence in
future pregnancies is high.

482

DISEASES AND DISORDERS

HYPOPITUITARISM PITUITARY TUMORS function. Treatment depends on the person’s Pituitary tumor
age and the size and nature of the tumor. A tumor may press on the optic nerves that
Drugs are given to suppress prolactin and pass just above it. This can cause headaches
growth hormone secretion. Surgery, and some loss of vision.
chemotherapy, or radiation therapy may
The pituitary gland secretes hormones Accounting for about 15 percent of brain be used to remove or shrink the tumor. Compressed Pituitary
that are vital for major body functions, so tumors, most pituitary tumors are The person may need replacement optic nerve tumor presses
hypopituitarism, or low activity of the benign; they usually grow slowly, and hormones afterward. on optic nerve
gland, can give rise to serious disorders. gradually secrete excess hormones. above

The pituitary gland helps regulate vital functions The most common tumors secrete growth Pituitary gland Anterior
such as growth, response to stress or infection, hormone and prolactin, producing symptoms cerebral
and fertility. It works in conjunction with the such as excessive growth or acromegaly, or
hypothalamus and adrenal glands, ovaries, and excessive breast milk production. Occasionally, artery
testes by means of feedback systems acting on the tumor growth has the opposite effect,
other glands. Hypopituitarism can result from a causing undersecretion of pituitary hormones LOCATION Pituitary gland
tumor, an infection, a vascular disorder such as (see left). Pressure from the tumor causes may fail to
stroke, or an autoimmune disease. Symptoms headaches, partial visual loss if the growth function
depend on the specific hormone deficiencies presses on the optic nerves, and palsy normally
and may include loss of sex drive, infertility, or, (paralysis or spasm) or numbness of the face.
in children, delayed growth. Treatment involves
removing the cause of the disorder and/or The tumor is diagnosed by skull MRI and
correcting deficiencies in “target” hormones CT scans to show the growth and its effects on
such as thyroid hormones. surrounding tissue, blood tests to show
relevant hormone levels, and tests of pituitary

HYPOTHYROIDISM retention, and mental slowing. Blood tests HYPERTHYROIDISM the overactivity of the metabolism, and include
reveal low levels of thyroxine (T4), secreted restlessness, anxiety, irritability, palpitations,
Underproduction of thyroid hormones, by the thyroid, and high levels of thyroid- This condition, also called thyrotoxicosis, weight loss, diarrhea, and breathlessness.
or hypothyroidism, causes slowing of the stimulating hormone (TSH), produced by the usually results from excess secretion of People with Graves’ disease may develop
metabolism—the continual chemical pituitary to make the thyroid work. The person thyroid hormones, and causes vital body exophthalmos, or bulging eyes. Complications
reactions that keep the body functioning. will need to take replacement thyroxine for life. functions to speed up. include heart disease and osteoporosis. Blood
tests will show high levels of the thyroid
Hypothyroidism is most often seen in adults, Goiter Oversecretion of thyroid hormones can have hormone thyroxine, and low levels of
due to an autoimmune condition in which the This swelling is due to an enlarged thyroid (goiter), various causes. The most common is Graves’ thyroid-stimulating hormone (TSH) from the
immune system attacks the body’s own thyroid which may be visible at the front of the neck. This disease, an autoimmune condition in which pituitary, as this gland tries to slow down the
tissue, causing thyroiditis (inflammation of may result from conditions such as hypothyroidism. the immune system attacks the thyroid gland, hormone secretion.
the thyroid gland), and is more common in stimulating it to make excess hormones; other
women, especially after menopause. It may thyroid disease, radiation therapy to the head causes include benign tumors called thyroid Treatments are designed to reduce levels of
also occur in newborn babies due to abnormal or neck, or an iodine-deficient diet make this nodules, and side effects of medication such as circulating thyroxine. Drugs such as carbimazole
development or a genetic disorder of type more likely. Medullary carcinomas are lithium. Symptoms develop slowly; they reflect may be given for 1 to 2 years, until the condition
metabolism. Symptoms result from slowing inherited. Thyroid carcinomas grow slowly, settles. Radioactive iodine may be introduced
of body functions and include fatigue, weight causing a lump, swollen glands, or hoarseness. Graves’ disease into the gland to destroy overactive thyroid
gain, constipation, dry hair and skin, fluid The autoimmune reaction in Graves’ disease tissue, or excess thyroid tissue may be removed.
Ultrasound and biopsy (tissue sampling) are causes inflammation and abnormal deposits in
THYROID CARCINOMA used to confirm the presence of a tumor, and the muscles and connective tissue behind the Eyeball is forced forward;
MRI, CT, and radioisotope scans to assess how eyes, affecting their shape and function. appears unusually prominent
Thyroid cancer, or thyroid carcinoma, is far it has spread. Treatment includes surgery,
rare but develops slowly and has good radioactive iodine, and radiation therapy to NORMAL (exophthalmos)
survival rates in people who are treated. remove or destroy affected thyroid tissue; in
some cases, the whole gland is removed. ABNORMAL
There are several types of thyroid carcinoma, Replacement thyroxine (the hormone normally
each arising from a different cell type: papillary, produced by the thyroid) is usually needed.
follicular, and medullary. The most common is
papillary carcinoma. Factors such as previous

Carcinoma of thyroid Eyeball sits neatly Swollen tissue causes Normal eye
Cancer can develop from any of the main thyroid in socket eyeball to protrude position
cell types. Medullary carcinoma (left) spreads at
an early stage than other types.

483

ENDOCRINE DISORDERS

GROWTH PROBLEMS ADDISON’S DISEASE corticosteroid treatment. Symptoms include
fatigue, muscle weakness, nausea, abnormal
Growth involves many body systems, so growth disorders may affect Damage to the cortex (outer layer) of the skin coloring, weight loss, and depression. A
not just stature but also organ development, recovery from wounds and adrenal glands may impair hormone sudden illness, injury, or other stress can cause
disease, and even skin, hair, and nails. Growth hormone, produced by production, leading to Addison’s disease. an Addisonian crisis, in which the gland cannot
the pituitary gland, plays a major role. In children, excess or deficiency produce enough hormones, causing circulatory
may affect their height. In adults, excess causes acromegaly, while low The adrenal cortex produces hormones that collapse; this needs urgent medical attention.
levels can cause muscle weakness, lack of energy, and depressed mood. help regulate metabolism, control blood Long-term treatment may include replacement
pressure, and balance the levels of salt and corticosteroids and mineralocorticoids.
ACROMEGALY enlargement in adults. This process is very water in the body. Insufficient corticosteroid
gradual, but eventually obvious changes occur: levels may be due to an autoimmune reaction Cortex
Excessive secretion of growth hormone in particular, growth of the hands, feet, lower in which the immune system attacks the
by the pituitary results in acromegaly: jaw, and eye sockets. Soft tissue changes adrenal glands; less common causes are Medulla
abnormal enlargement of the face, include thick lips, large tongue, and leathery, infections, certain drugs, or suddenly stopping
hands, feet, and soft tissues. greasy, darkened skin with acne. Internal Blood vessel
organs such as the liver, heart, and thyroid also Adrenal anatomy
Acromegaly is almost always due to a tumor enlarge, causing problems such as heart failure. The adrenal glands sit on the kidneys. The medulla Pad of
in the pituitary gland (see opposite) that is Excess growth hormone can also induce (center) secretes epinephrine and norepinephrine; fat
secreting excessive amounts of growth diabetes and other metabolic disorders, high the cortex produces a variety of hormones.
hormone. The effects can be seen in the bones blood pressure, and nerve and muscle damage. Kidney
and soft tissues of the body. In children it may CUSHING SYNDROME
cause gigantism, or excessive growth. Although Blood tests show abnormal hormone and dysfunction in men and irregular menstrual
the bones stop growing after puberty, excess mineral levels, and X-rays and MRI or CT scans If the adrenal glands produce an excess periods in women, can also occur. Treatment
growth hormone can still cause bone can reveal the bone changes. People with a of cortisol (the major corticosteroid in the is based on identifying and treating the cause
tumor may have surgery or radiation therapy to body), Cushing syndrome may develop. of the syndrome. In Cushing’s disease, surgery,
remove or shrink it. In other cases, drugs may with radiation therapy or medication, is used
be given to reduce growth hormone levels. to reduce the pituitary’s stimulation of the
adrenal glands and thus lower adrenal activity.

GROWTH DISORDERS Thick lip There are many possible causes of Cushing Stretch marks
IN CHILDREN syndrome; the most common is Cushing’s One of the signs of high corticosteroid levels is
Enlarged, disease, in which the pituitary gland stimulates the stretching and tearing of skin layers, causing
Childhood growth can be affected by prominent jaw the adrenals to oversecrete corticosteroids. stretch marks, especially where there is
abnormalities in genes, hormonal The symptoms of Cushing syndrome include underlying fat, as on the torso and upper limbs.
function, nutrition, and general health, Effects of obesity; excess fat deposits, especially in the
as well as growth patterns in the family. acromegaly face and over the shoulders; excess growth of Overactivity, often due to a tumor in a gland,
This MRI scan shows body hair; high blood pressure; and diabetes. leads to an excess of PTH, which causes calcium
The normal growth of a child is highly complex the enlarged jaw and Other symptoms include thinning of the skin to leach from the bones into the blood. This
and affected by every aspect of physical and coarsened facial and hair, weakness, and osteoporosis leading results in thinning of the bones, fractures,
mental health. Growth abnormalities can be features of acromegaly. to fractures. Recurrent infections and sex and calcium deposits in the kidneys and other
divided into two main types. Abnormal growth hormone disturbances, resulting in erectile tissues. An underactive parathyroid is usually
patterns causing short stature and/or body disorders or genetic programming, as in
disproportion may be due to metabolic achondroplasia (see p.417), a chromosomal DISORDERS OF CALCIUM treated with
abnormality that is one of the most common METABOLISM vitamin D
causes of dwarfism. Some disorders are due to and calcium
overly high or low levels of hormones, notably An overactive or underactive parathyroid supplements.
growth hormone, produced by the pituitary gland can cause levels of calcium in the Surgery may
gland. An excess of growth hormone causes body to be affected, leading to disorders. be needed
gigantism, or extreme bone growth, while a to remove
deficit can cause a child to grow too slowly. Calcium is needed for bone and tissue growth a tumor.
and muscle and nerve function. The levels are
Lack of thyroxine, from the thyroid, can regulated by parathyroid hormone (PTH). If the Superior
also delay growth and development. By contrast, parathyroid glands are underactive, PTH levels parathyroid
poor growth (compared to other children the fall too low, leading to low calcium levels; this gland
same age) but normal proportions may be due can cause muscle cramps and nerve problems.
to poor nutrition or chronic disease. To treat Inferior
a growth disorder, the underlying cause needs Parathyroid glands parathyroid
to be identified and remedied. The four glands lie at the back of the thyroid, just gland
under the larynx in the neck. If calcium levels are
low they secrete PTH, which draws calcium out
of the bones and increases absorption from food.

484

GLOSSARY

Glossary androgen -ase brain stem

Terms defined elsewhere in the glossary are in Steroid hormones that tend to promote male A suffix denoting an enzyme. For example, The lowest part of the brain, leading down from
italics. All distinct terms are in bold. body and behavioral characteristics. They are sucrase is an enzyme that breaks down the rest of the brain to the spinal cord. In
secreted in larger amounts by men than women. sucrose. descending order, it consists of the midbrain,
abduction pons, and medulla oblongata.
anemia ATP
The action of moving a limb farther from the bronchus (pl. bronchi)
midline of the body. In muscle names, abductor Damagingly low amounts of hemoglobin in the Short for adenosine triphosphate, an
indicates a muscle that has this action. See also blood. Anemia can have many causes, from energy-storing molecule used by all living cells. The air tubes branching from the trachea and
adduction. undetected bleeding to vitamin deficiencies. leading into the lungs; right and left main bronchi
atrium (pl. atria) enter each lung respectively and divide into lobar
acetylcholine angio- bronchi, and eventually into much smaller tubes
Either of the two smaller chambers of the called bronchioles.
A major neurotransmitter in the body, conveying A prefix relating to blood vessels. heart that receive blood from the veins and
signals from nerves to muscles as well as between pass it on to the corresponding ventricle. calcitonin
many nerves. angiography
autoimmunity See thyroid gland.
action potential In medical imaging: any technique for obtaining
images of blood vessels in the living body. A situation where the immune system cancer
The electrical nerve impulse that travels along the attacks the body’s own tissues, often leading
axon of a nerve cell (neuron). antagonist to disease. An uncontrolled growth of cells with the potential
to spread and form colonies elsewhere in the body.
adduction 1. A muscle that has the opposite action to autonomic nervous system Cancer cells typically look different from their
another muscle. non-cancerous equivalents under the microscope.
The action of moving a limb closer to the midline 2. A drug that interferes with the action of a The part of the nervous system that controls Cancers can arise in many different tissues.
of the body. In muscle names, adductor indicates hormone, neurotransmitter, etc., by binding to non-conscious processes such as the activity
a muscle that has this action. See also abduction. its receptor. of the body’s glands and the muscles of the cannula
gut. It is divided into the sympathetic
adipose tissue anterior nervous system, the roles of which include A tube inserted into any part of the body to drain
preparing the body for “fight or flight,” and the fluid, introduce drugs, etc. See also catheter.
Fat-storage tissue. Toward the front of the body, when considered in parasympathetic nervous system, which
a standing position. Anterior to means in front stimulates movement and secretions in the capillaries
adrenal glands of. See also posterior. gut, produces erection of the penis during
coitus, and empties the bladder. The smallest blood vessels, with a wall only one
Also called suprarenal glands. A pair of glands antibiotic cell thick, supplied by arterioles and draining into
found one on top of each kidney. Each gland axon veins. Capillaries form networks, and are the sites
consists of an outer adrenal cortex, which Any of various chemical compounds, natural or where nutrients, gases, and waste products are
secretes corticosteroid hormones, and an inner synthetic, that destroy or prevent the growth of A wirelike extension of a nerve cell (neuron) exchanged between body tissue and blood.
adrenal medulla, which secretes epinephrine. microorganisms (e.g. bacteria, yeasts, and fungi). along which electrical signals are transmitted
See also corticosteroid. away from the cell. carbohydrates
antibody
adrenaline bacterium (pl. bacteria) Naturally occurring chemical substances
Defensive proteins produced by white blood cells containing carbon, hydrogen, and oxygen atoms,
See epinephrine. that recognize and attach to particular “foreign” Any member of a large group of single-celled e.g. sugars, starch, cellulose, and glycogen.
chemical components (antigens), such as the living organisms, some of which are dangerous
afferent surface of an invading bacterium or virus. The pathogens. Bacterial cells are much smaller cardiac
body is able to produce thousands of different than animal and plant cells, and lack nuclei.
In blood vessels, carrying blood toward an organ, antibodies targeted at different invaders and toxins. Relating to the heart.
and in nerves, conducting impulses toward the basal ganglia
central nervous system. See also efferent. anticoagulant carpal
Groups of nerve cells deep in the cerebrum;
aldosterone A substance that prevents blood clotting. consists of the caudate nucleus, putamen, Relating to the wrist.
globus pallidus, and subthalamic nucleus.
See corticosteroid. antigen Functions include controlling movement. cartilage

allergy Any particle or chemical substance that basophil A rubbery or tough supportive tissue (colloquially
stimulates the immune system to produce “gristle”) found in various forms around the body.
An unnecessary and sometimes dangerous antibodies against it. A type of leukocyte (white blood cell).
immune response that targets otherwise non- catheter
threatening foreign material, such as plant pollen. aorta belly (of muscle)
A tube inserted into the body, for example, a
alveolus (pl. alveoli) The body’s largest artery, conveying blood The widest part of a skeletal muscle, which urinary catheter may be inserted into the urethra
pumped by the left ventricle of the heart. It bulges further when it contracts. to drain urine from the bladder.
A small cavity; specifically, one of the millions of extends to the lower abdomen, where it
tiny air sacs in the lungs where exchange of gases divides into the two common iliac arteries. bilateral cecum
with the blood takes place; also, the technical
term for a tooth socket. aponeurosis Concerning or affecting both sides of the The first part of the large intestine.
body or a body part.
amino acid A flattened, sheetlike tendon. cell
bile
Proteins are made from up to 20 different types of arteriole A tiny structure containing genes, a surrounding
these small, nitrogen-containing molecules; amino A yellow-green fluid produced by the liver, fluid (cytoplasm) that carries out chemical
acids also play various other roles in the body. A very small artery, leading into capillaries. stored in the gallbladder, and discharged into reactions, organelles, and an enclosing membrane.
See also peptide. the intestine via the bile duct. It contains See also nucleus.
artery excretory products together with bile acids
amnion that help with fat digestion. central nervous system
A vessel carrying blood from the heart to the
The membrane that encloses the developing tissues and organs of the body. Arteries have biopsy The brain and spinal cord, as distinct from the
fetus within the uterus (womb). The fluid inside thicker, more muscular walls than veins. nerves that run through the rest of the body (the
it (amniotic fluid) helps cushion and protect A sample taken from a living body to test for peripheral nervous system).
the fetus. articulation infection, cancerous growth, etc.; also the
sampling process. cerebellum
anastomosis A joint, especially one allowing movement; also, a
location within a joint where two bones meet in blood–brain barrier An anatomically distinct region of the brain
An interconnection between two otherwise close proximity. A bone in a joint is said to below the back of the cerebrum, responsible for
separate blood vessels (e.g. two arteries, or an articulate with the other bone(s) of the joint. The arrangements by which the brain is coordinating the details of complex bodily
artery and a vein). relatively protected from unwanted movements, and managing balance and posture.
substances entering it from the blood. It
includes capillaries that are less permeable to cerebrospinal fluid
large molecules than elsewhere in the body.
The clear fluid that fills the ventricles of the brain
brachial and surrounds the brain and spinal cord, helping
to provide a constant environment and acting as
Relating to the arm. a shock absorber.

485
GLOSSARY

cerebrum acellular matrix; includes cartilage, bone, diaphragm enzyme
tendon, ligament, and blood.
The largest part of the brain and the locus of A sheet of muscle that separates the thorax from Any of a large variety of different molecules
most “higher” mental activities; part of the cornea the abdomen. When relaxed it is domed upward; (most of which are proteins) that catalyze a
forebrain in evolutionary terms. It is divided into it flattens when contracted, to increase thoracic particular chemical reaction in the body.
two halves called cerebral hemispheres. The tough, transparent, protective layer at the volume and draw air into the lungs. It is the most
front of the eye; helps focus light on the retina. important muscle used in breathing. eosinophil
cervical
coronal section diastole A type of leukocyte (white blood cell).
1. Relating to the neck.
2. Relating to the cervix (neck) of the uterus. A real or imagined section down the body that The phase of the cardiac cycle when the heart epicondyle
divides it from side to side; it is perpendicular to a relaxes and the ventricles refill with blood.
cervix sagittal section. A small bulge found on some bones near a joint,
diffusion usually forming a site for muscle attachment.
The narrow “neck” of the uterus, opening into the corpus callosum
upper end of the vagina; widens during childbirth. The net movement of molecules in a fluid epidermis
A large tract of nerve fibers (commissure) that (gas or liquid) from regions of high to lower
cholesterol links the brain’s two cerebral hemispheres. concentration. The outermost layer of skin, with a surface
consisting of dead cells packed with the tough
A natural chemical that is an essential constituent cortex dilated protein keratin.
of the body’s cell membranes and is an intermediate
molecule in the production of steroid hormones. It The Latin word for bark, used for the outer parts Opened or stretched wider. epiglottis
is a constituent of the plaques that cause the of some organs, especially:
arteries to narrow in atherosclerosis. 1. The cerebral or cerebellar cortex—the distal A flexible flap of cartilage in the throat that
surface layers of cells (the “gray matter”) of these helps cover the trachea (windpipe) during
chromosomes parts of the brain. Relatively farther away from the center of the swallowing.
2. The adrenal cortex—the outer part of the body or from the point of origin. See also
The microscopic packages in the nucleus of a cell adrenal glands. proximal. epinephrine
that contain genetic information in the form of
DNA. Humans have 23 pairs of chromosomes, corticosteroid DNA A hormone released by the adrenal glands in
with a complete set present in nearly every cell of response to stressful situations. It prepares the
the body. Each chromosome consists of a single Any of several steroid hormones produced by Short for deoxyribonucleic acid, a very long body for a “fight or flight” response by increasing
DNA molecule combined with various proteins. the adrenal cortex. Examples include cortisone molecule made up of small individual units or heart rate, diverting blood flow to muscles, etc.
and cortisol (hydrocortisone), which have many nucleotides, containing one of four bases. DNA
cilium (pl. cilia) effects on the body’s metabolism and also is found in the chromosomes of living cells; the epithelium
suppress inflammation. The mineral-regulating order of the bases “spells out” the genetic
A microscopic, beating, hairlike structure found in hormone aldosterone is also a corticosteroid. instructions of the animal. See also gene. Any tissue that forms the surface of an organ or
large numbers on the surfaces of some cells—for structure. It may consist of a single layer of cells,
example in the air tubes of the lungs, where they cranial dopamine or several layers.
help remove foreign particles.
1. Relating to the cranium. A neurotransmitter secreted mainly by groups of erythrocyte
circadian rhythm 2. Toward the head. neurons whose cell bodies lie deep in the brain.
Dopamine-producing regions are involved in A red blood cell.
An internal, daily body rhythm. It is kept accurate cranial nerves motivation, mood, control of movement, and
by reference to external light and dark. other functions. esophagus
Pairs of nerves that lead directly from the brain
clone rather than from the spinal cord. They mainly dorsal The gullet: the tubular part of the alimentary
supply structures in the head and neck. canal between the pharynx and the stomach.
An identical copy or set of copies. Depending on Relating to the back or back surface of the body,
the context, it can refer to: copied DNA molecules; cranium or to the top of the brain; also, relating to the estrogens
a set of identical descendants of a given cell; or an back (dorsum) of the hand or the upper surface
animal bred artificially using genetic material Together with the mandible (jaw), forms the skull. of the foot. Steroid hormones produced predominantly by
from another adult individual. the ovary, and which regulate female sexual
CSF duodenum development and physiology. Artificial estrogens
CNS are used in oral contraceptives and hormone
Short for cerebrospinal fluid. The first part of the small intestine, leading out of therapy.
Short for central nervous system. the stomach.
CT extension
cochlea efferent
Short for computed tomography, a The movement that increases the angle of, or
The complex spiral structure in the inner ear that sophisticated X-ray technique that produces In the case of blood vessels, carrying blood away straightens, a joint. The name extensor indicates
translates sound vibrations in the fluid it contains images in the form of “slices” through the from an organ; in the case of nerves, conducting a muscle that has this action, e.g. extensor
into electrical impulses to be sent to the brain. patient’s body. impulses away from the central nervous system. digitorum extends the fingers. See also flexion.
See also afferent.
collagen cutaneous external
electrocardiography
A tough, fibrous, structural protein that is Relating to the skin. In anatomy: closer to the outer surface.
widespread in the body (particularly in bone, Recording the electrical activity produced
cartilage, blood-vessel walls, and skin). cyst by the heart muscle, using electrodes applied extracellular
to the patient’s skin.
colon A fluid-filled cavity in the body. Also, an old term Outside the cell; often used in reference to the
for the bladder; hence cystitis. embryo fluid or matrix between cells of a connective tissue.
The main part of the large intestine; comprises
the ascending, transverse, and descending colon. deficiency disease The earliest stage of a developing unborn fallopian tube
individual in the uterus, from fertilization until
commissure Any disease caused by a lack of an essential 8 weeks of gestation (after which it is known Another name for the oviduct or uterine tube;
component of the diet, e.g. a protein or vitamin. as a fetus). two oviducts attach to the uterus, extending to
A link between two structures, especially any of the ovary on each side; the ovum travels down
several nerve tracts in the brain and spinal cord dendrite endocrine system this tube after ovulation.
that crosses the midline of the body.
A branchlike outgrowth of a nerve cell (neuron) The system comprising glands that produce fascia (pl. fasciae)
compartment (as in anatomical that carries incoming electrical signals to that cell. hormones.
grouping or area) A neuron usually has many dendrites. Layers of fibrous tissue between and around
endometrium muscles, vessels, and organs.
In the case of muscles, used to define an depressor
anatomically and functionally discrete group of The inner lining of the uterus. fertilization
muscles, e.g. flexor compartment of the forearm. Term used in names of several muscles that act to
pull down, e.g. depressor anguli oris (pulls down endorphins The union of a sperm with an unfertilized egg
condyle the angle of the mouth). See also levator. (ovum), the first step in the creation of a new
Neurotransmitters in the brain; their functions individual. See also zygote.
A rounded, knucklelike projection on a bone that diabetes include diminishing the perception of pain.
forms part of a joint. fetus
Short for diabetes mellitus, a condition endothelium
connective tissue involving high levels of glucose (sugar) in the The unborn individual in the uterus, from
blood, caused by insufficient production of The cell layer that forms the inner lining of blood 8 weeks after fertilization, when it begins to s
Any tissue comprising cells embedded in an the hormone insulin. vessels. how a recognizably human appearance.
See also embryo.

486

GLOSSARY

flexion globulin immune response intrinsic

The bending movement at a joint. The name flexor A general name for various proteins found in the The body’s defensive reactions to invasion by a Situated within or originating within a particular
indicates a muscle that has this action, e.g. flexor blood that have a roughly spherical shape. bacterium, virus, toxin, etc. It includes general organ or body part.
carpi ulnaris bends the wrist. See also extension. responses such as inflammation, as well as
glomerulus specific responses in which an invader is targeted ion
follicle by a particular antibody so that it can be
A cluster of nerve endings or capillaries, such as recognized and destroyed or disabled. An electrically charged atom or molecule.
A small cavity or saclike structure: e.g. the hair the tiny knot of capillaries enclosed in the cuplike
follicle from which a hair grows. Bowman’s capsule of a nephron. immune system ischemia

foramen gloss-, glosso- The molecules, cells, organs, and processes that Reduction of blood supply to part of the body.
are involved in defending the body against disease.
An opening, hole, or connecting passage. Prefixes relating to the tongue. islets of Langerhans
immunity
fossa glucagon See pancreas.
Resistance to attack by a pathogen (disease-
A shallow depression or cavity. A hormone produced by the pancreatic islets (see causing organism); specific immunity develops -itis
pancreas) that increases glucose levels in the as a result of the body’s immune system being
frontal blood; its effect is opposite to that of insulin. primed to resist a particular pathogen. Suffix meaning “inflammation,” used in words
such as tonsillitis and laryngitis.
Relating to or in the region of the forehead; glucose immunotherapy
frontal bone, the skull bone of the forehead; joint
frontal lobe, the foremost lobe of each cerebral A simple sugar that is the main energy source Any of various treatments involving either the
hemisphere, lying behind the forehead. used by the body’s cells. stimulation or suppression of the activity of Any junction between two or more bones,
the immune system. whether or not movement is possible between
gallbladder glycogen them. See also articulation, suture, symphysis,
implantation synovial joint.
The hollow organ into which bile (formerly A carbohydrate made up of long, branched chains
known as gall) secreted by the liver is stored of connected glucose molecules. The body stores The attachment of an early embryo to the lining keratin
and concentrated before being transferred glucose in the form of glycogen, especially in the of the uterus. It occurs during the first week after
to the intestine. muscles and liver; also called animal starch. fertilization, and is followed by the development A tough protein that forms the substance of hair
of the placenta. and nails, gives strength to the skin, etc.
gamete gonad
inferior labia (sing. labium)
A sperm or an ovum (egg). Gametes contain just An organ that produces sex cells (gametes)
one set of 23 chromosomes, whereas normal body —i.e. an ovary or a testis. A gonadotropin is a Lower down the body, when considered in Either of the two paired folds that form part of
cells have two sets (46 chromosomes). When hormone that specifically affects the gonads. a standing position (i.e. nearer the feet). See the vulva in females: the outer labia majora and
sperm and egg combine during fertilization, the also superior. the more delicate inner labia minora.
two-set condition is restored. See also zygote. gyrus (pl. gyri)
inflammation labial
ganglion One of the folds on the outer surface of the brain.
See also sulcus. An immediate reaction of body tissue to damage, Relating to the lips, or to the labia of the female
1. A concentration of nerve cell bodies, especially in which the affected area becomes red, hot, genitals.
one outside the central nervous system. head (of a muscle) swollen, and painful, as white blood cells
2. A swelling on a tendon sheath. (see leukocyte) accumulate at the site to lactation
Where a muscle has several origins or proximal attack potential invaders.
gastric attachments, these may be referred to as “heads,” Secretion of milk by the breasts.
as in the long and short heads of biceps brachii. inguinal
Relating to the stomach. larynx
hemoglobin Relating to, or in the region of, the groin.
gene The voicebox: a complex structure situated at the
The red pigment within erythrocytes that gives inner ear top of the trachea. It includes the vocal cords,
A length of a DNA molecule that contains a blood its color and carries oxygen to the tissues. structures that function to seal off the trachea
particular genetic instruction. Many genes The fluid-filled innermost part of the ear, which when necessary, as well as creating sound when
are blueprints for making particular protein hepatic contains the organs of balance (the semicircular their edges are made to vibrate during breathing.
molecules, while some have a role in controlling canals) and the organs of hearing within the
other genes. Among them, the thousands of Relating to the liver. cochlea. See also middle ear. lateral
different genes in the body provide the
instructions for a fertilized egg to grow into an histamine insertion Relating to or toward the sides of the body. See
adult, and for all essential activities of the body also medial.
to be carried out. Nearly every cell in the body A substance produced by damaged or irritated The point of attachment of a muscle to the
contains an identical set of genes, although tissues that stimulates an inflammatory response structure that typically moves when the muscle leukocyte
different genes are “switched on” in different cells. (see inflammation). is contracted. See also origin.
A white blood cell. There are several types, acting
genome homeostasis insulin in different ways to protect the body against
disease as part of its immune response. Leukocytes
The complete set of genes found in a human The maintenance of stable conditions in the body, A hormone produced by the pancreatic islets (see are found in lymph nodes and other tissues
or other living species. The human genome e.g. in terms of chemical balance or temperature. pancreas) that promotes the uptake of glucose generally, as well as in the blood.
is thought to contain about 20,000–25,000 from the blood, and the conversion of glucose to
different genes. hormone the storage molecule, glycogen. See also diabetes. levator

genotype A chemical messenger produced by one part of integument Term used in the names of several muscles whose
the body that affects other organs or parts. There action is to lift up, such as the levator scapula (lifts
The genetic makeup of a particular individual. also exist local hormones that affect only nearby The external protective covering of the body. the shoulder blade). See also depressor.
Identical twins, for example, have the same cells and tissues. Chemically, most hormones are
genotype because they share identical versions either steroids, peptides, or small molecules related internal ligament
of all their genes. to amino acids. See also neurohormone,
neurotransmitter. In anatomy: inside the body, distant from the A tough fibrous band that holds two bones
gland surface. See also external. together. Many ligaments are flexible, but they
hydrocortisone cannot be stretched. The term is also used for
A structure in the body, the main purpose of interneuron bands of tissue connecting or supporting some
which is to secrete particular chemical substances See corticosteroid. internal organs.
or fluids. Glands are either exocrine, releasing Any nerve cell whose connections are only with
their secretions through a duct onto an external hypothalamus other neurons, as distinct from a sensory or limbic system
or internal surface, such as the salivary glands, motor neuron.
or endocrine, releasing hormones into the A small but vital region at the base of the brain, Several regions at the base of the brain, involved
bloodstream. See also endocrine system. which is the control center for the autonomic interstitial in memory, behavior, and emotion.
nervous system, regulating processes such as
glial cells body temperature and appetite. Also controls the Relates to being between things, such as other lingual
secretion of hormones from the pituitary gland. cells or tissues, e.g. interstitial fluid surrounds cells.
Cells in the nervous system that are not neurons Relating to the tongue.
but play various supportive and protective roles ileum intra-
within the nervous system. lipid
The last part of the small intestine, ending at the Prefix meaning within, as in intracellular or
junction with the large intestine (colon). N.B: Not intramuscular. Any of a large variety of fatty or fatlike substances
the same as ilium, one of the bones of the hip. that are found naturally in living things and are
relatively insoluble in water.

487
GLOSSARY

lumbar molecules with other molecules such as proteins during cell division. Mutations in sex cells nondisjunction
embedded in it. (gametes) may cause offspring to have unusual
Relating to the lower back and sides of the body genetic features not present in their parents. Failure of chromosomes to separate from each
between the lowest ribs and the top of the hip meninges other properly during cell division, resulting in
bone. The lumbar vertebrae are the vertebrae myelin daughter cells that have either too many or
that lie within this region. Membranes that enclose the outside of the brain too few chromosomes.
and spinal cord. Meningitis is inflammation of the Fatty substance forming a layer around some
lumen meninges, usually resulting from infection. nerve axons, called myelinated axons, insulating noradrenaline
them and speeding their nerve impulses.
The space inside a tubular structure, such as a menopause See norepinephrine.
blood vessel or glandular duct. myelo-
The time in a woman’s life when ovulation and the norepinephrine
lymph node menstrual cycle permanently cease. 1. Prefix relating to the spinal cord.
2. Prefix relating to bone marrow. A neurotransmitter important in the sympathetic
A small lymphoid organ; lymph nodes serve to menstrual cycle nervous system.
filter out and dispose of bacteria and debris, such myo-
as cell fragments. The monthly cycle that takes place in the uterus nucleus (pl. nuclei)
of a non-pregnant woman of reproductive age. Prefix relating to muscle.
lymphocyte The endometrium (lining of the uterus) grows 1. The structure within a cell that contains the
thicker in preparation for possible pregnancy; an natural killer (NK) cell chromosomes.
A specialized leukocyte that produces antibodies egg is released from the ovary (ovulation); then, if 2. Any of various concentrations of nerve cells
including natural killer cells, T-cells, and B-cells. the egg is not fertilized, the endometrium breaks A type of lymphocyte that can attack and kill within the central nervous system.
down and is discharged through the vagina cancer cells and virus-infected cells. 3. The central part of an atom.
lymphoid tissue in a process known as menstruation.
necrosis occipital
The tissue of the lymphatic system, which has an mental
immune function, including lymph nodes, the The death of part of an organ or tissue. Relating to the back of the head. The occipital
thymus, and the spleen. 1. Relating to the mind (Latin mens). bone is the skull bone forming the back of the
2. Relating to the chin (Latin mentum). neocortex head. The occipital lobe is the rearmost lobe
macromolecule of each cerebral hemisphere, lying below the
mesentery All the cortex of the cerebrum except the region occipital bone.
A large molecule, especially one that consists of a concerned with smell and the hippocampal
chain of small similar “building blocks” joined A folded sheet of peritoneum, forming a formation. olfactory
together. Proteins, DNA, and starch are examples connection between the intestines and the back
of macromolecules. of the abdominal cavity. nephron Relating to the sense of smell.

macrophage metabolism The filtering unit of the kidney, which regulates optic nerve
the volume and composition of body fluids
A large type of leukocyte that can engulf and The chemical reactions taking place in the body. by filtering the blood to produce urine. Waste The nerve that transmits visual information from
dispose of cell fragments, bacteria, etc. The metabolic rate is the overall rate at which products, such as urea and uric acid, are also the retina of the eye to the brain.
these reactions are occurring. excreted by the nephron. There are more than
mammary a million nephrons in each kidney. oral
midbrain
Of, or relating to, the breasts. nerve Relating to the mouth.
The upper part of the brain stem.
marrow A cablelike structure transmitting information and orbit
middle ear control instructions in the body. A typical nerve
In anatomical contexts, usually short for bone consists of axons of many separate nerve cells The bony hollow in the skull within which the
marrow, the soft material located in the cavities The air-filled middle chamber of the ear, between (neurons) running parallel to, but insulated from, eye is contained.
of bones; in some areas this tissue is mainly fat; in the inner surface of the eardrum and the inner each other; the nerve itself is surrounded by an
others, it is blood-forming tissue. ear. See also ossicles. overall protective sheath of fibrous tissue. Nerves organelle
may contain nerve fibers controlling muscles or
matrix molecule glands (efferent fibers), while others contain Any of a variety of small structures inside a cell,
fibers carrying sensory information back to the usually enclosed within a membrane, which are
The extracellular material in which the cells of The smallest unit of a chemical compound that brain (afferent fibers); some nerves carry both specialized for functions such as energy
connective tissues are embedded. It may be hard, can exist, consisting of two or more atoms joined types of nerve fiber. production or secretion.
as in bone; tough, as in cartilage; or fluid, as together by chemical bonds. The water molecule
in blood. is a simple example, consisting of two hydrogen neurohormone origin
atoms joined to one oxygen atom. See also
meatus macromolecule. A hormone released by a nerve cell rather than The point of attachment of a muscle to the
from a gland. structure that typically remains stationary
A channel or passage. For example, the external monocyte when the muscle is contracted.
auditory meatus, the ear canal. neurology See also insertion.
A type of leukocyte with various roles in the
medial immune system, including giving rise to The branch of medicine that specializes in osmosis
macrophages. disorders of the nervous system. The adjective
Toward the midline of the body. See also lateral. neurological includes any symptom or disorder Phenomenon in which water moves from a less
motor that might fall within the province of neurology. concentrated solution to a more concentrated
medulla one if the two solutions are separated by a
Adjective relating to the control of muscle neuron semipermeable membrane.
1. Short for medulla oblongata, the elongated movements, as in motor neuron, motor
lower part of the brain that connects with the function, etc. See also sensory. A nerve cell. A typical neuron consists of a ossi-, osteo-
spinal cord. rounded cell body; branchlike outgrowths called
2. The central part or core of some organs such MRI scan dendrites that carry incoming electrical signals to Prefixes relating to bone.
as the kidneys and adrenal glands. the neuron; and a single, long, wirelike extension,
Short for magnetic resonance imaging scan, a called an axon, which transmits outgoing ossicles
melanin medical imaging technique based on the energy messages. There are many variations on this
released when magnetic fields are applied then basic pattern, however. Three small bones of the middle ear that transmit
A dark brown naturally occurring pigment removed from the body; it can produce very vibrations caused by sound waves from the
molecule, which occurs in greater amounts detailed images of the soft tissues of the body. neurotransmitter eardrum to the inner ear.
in tanned or darker skin, and protects deeper
tissues from ultraviolet radiation. mucosa (pl. mucosae) Any of various chemical substances released at ovary
synapses by the ends of nerve cells, where they
melatonin A membrane that secretes mucus. function to pass a signal on to another nerve cell Either of the two organs in females that produce
or muscle. Some neurotransmitters act mainly and release egg cells (ova). They also secrete sex
A hormone secreted by the pineal gland in the mucus to stimulate the action of other cells, others to hormones.
brain, which plays a role in the body’s sleep–wake inhibit them.
cycle (see circadian rhythm). A thick fluid produced by some membranes of the ovulation
body for protection, lubrication, etc. (Adjective neutrophil
membrane mucous.) The point in the menstrual cycle at which an egg
The most common type of leukocyte (white blood cell (ovum) is released from the ovary and begins
1. A thin sheet of tissue covering an organ, or mutation cell). Neutrophils move quickly toward sites of to travel toward the uterus.
separating one part of the body from another. damage and engulf invading bacteria etc.
2. The outer covering of a cell (and similar Any change to the genetic makeup of a cell, ovum (pl. ova)
structures within the cell). A cell membrane is caused for example by accidents or mistakes
composed of a double layer of phospholipid An unfertilized egg cell.

488

GLOSSARY

oxytocin peritoneum prolactin ribosomes

A hormone secreted by the pituitary gland A thin, lubricated sheet of tissue that enfolds and A hormone produced by the pituitary gland, the Particles within cells involved in protein synthesis.
involved in dilation of the cervix and uterine protects most of the organs of the abdomen. effects of which include stimulating the breasts
contractions during childbirth, in lactation, to produce milk. RNA
and in sexual responses. phagocyte
pronation Short for ribonucleic acid, a long molecule
palate Any cell that can engulf and dispose of foreign similar to DNA, but usually single- rather than
bodies such as bacteria, as well as broken The rotation of the radius around the ulna in the double-stranded. RNA has many important roles
The roof of the mouth, comprising the bony fragments of the body’s own cells. forearm, turning the palms of the hand to face including making copies of the DNA code for
hard palate in the front and the muscular soft downward or backward. In muscle names, protein synthesis.
palate behind it. pharynx pronator indicates a muscle that has this action,
e.g. pronator teres. See also supination. sacral
pancreas The muscular tube behind the nose, mouth, and
larynx, leading into the esophagus. prostate gland Relating to or in the region of the sacrum, the
A large, elongated gland lying behind the bony structure made up of fused vertebrae at the
stomach, with a dual role in the body. The bulk of phospholipid A gland located below the male bladder; its base of the spine that forms part of the pelvic girdle.
its tissue secretes digestive enzymes into the secretions contribute to semen.
duodenum, but it also contains scattered groups of A type of lipid molecule with a phosphate sagittal section
cells called pancreatic islets or islets of (phosphorus plus oxygen) group at one end. proteins
Langerhans that produce important hormones, The phosphate group is attracted to water while A real or imagined section down the body, or part
including insulin and glucagon. the rest of the molecule is not. This property Large molecules consisting of long folded chains of the body, that divides it into right and left sides.
makes phospholipids ideal for forming cell of small linked units (amino acids). There are
parasympathetic nervous membranes if two layers of molecules are thousands of different kinds in the body. Nearly scrotum
system situated back-to-back. all enzymes are proteins, as are the tough
materials keratin and collagen. See also peptide. The loose pouch of skin holding the testes in males.
See autonomic nervous system. physiology
proximal sebum
parathyroid glands The study of the normal functioning of body
processes; also, the body processes themselves. Relatively closer to the center of the body or from An oily, lubricating substance secreted by
Four small glands that are often embedded in but the point of origin. See also distal. sebaceous glands in the skin.
are separate from the thyroid gland. They produce pituitary gland
parathyroid hormone, which regulates calcium puberty semen
metabolism in the body. Also called the hypophysis, a complex pea-sized
structure at the base of the brain, sometimes The period of sexual maturation between The fluid released through the penis when the
parietal described as the body’s “master gland.” It childhood and adulthood. male ejaculates; it contains sperm and a mixture of
produces various hormones, some affecting the nutrients and salts. Also called seminal fluid.
A term (derived from the Latin word for “wall”) body directly and others controlling the release pulmonary
with various applications in anatomy. The of hormones by other glands. sensory
parietal bones form the side walls of the skull, Relating to the lungs.
and the parietal lobes of the brain lie beneath placenta Concerned with transmitting information coming
those bones. Membranes (such as the pleura and pyloric from the sense organs of the body.
peritoneum) are described as parietal where they The organ that develops on the inner wall of the
are attached to the body wall. uterus during pregnancy, allowing the transfer Relating to the last part of the stomach, serotonin
of substances, including nutrients and oxygen, or pylorus. The muscle wall of the end of the
pathogen between maternal and fetal blood. See also pylorus is thickened to form the pyloric A neurotransmitter in the brain that affects many
umbilical cord. sphincter. mental activities, including mood. It is also active
Any disease-causing agent, including bacteria in the gut.
and viruses. plasma radiation therapy
serous membrane
pathology Blood minus its cellular components (red and Cancer treatment using ionizing radiation, carried
white blood cells, and platelets). out by directing beams of radiation at the cancer, A type of body membrane that secretes lubricating
The study of disease; also, the physical or introducing radioactive substances to the body. fluid and envelops various internal organs and
manifestations of a disease. platelets body cavities. The pericardium, pleura, and
receptor peritoneum are all serous membranes.
pelvic girdle Specialized fragments of cells that circulate in
the blood and are involved in blood clotting. 1. Any sense organ, or the part(s) of a sense organ shock
The hip bones attach to the sacrum to form the responsible for collecting information.
pelvic girdle, linking the leg bones to the spine. pleura (pl. pleurae) 2. A molecule in a cell, or on a cell’s outer Medical or circulatory shock: a potentially fatal
membrane, that responds to an outside stimulus, failure of the blood flow to support the body’s
pelvis The lubricated membrane that lines the inside of such as a hormone molecule attaching to it. needs, as a result of blood loss or other causes.
the thoracic cavity and the outside of the lungs. The term is also used more loosely to refer to
1. The cavity enclosed by the pelvic girdle, or the rectum psychological responses to trauma, etc.
area of the body containing the pelvic girdle. plexus
2. The renal pelvis is the cavity in the kidney The short final portion of the large intestine, sinus
where the urine collects before passing down A network, usually in reference to nerves or blood connecting it to the anal canal.
the ureter. vessels. A cavity; especially:
rectus 1. One of the air-filled cavities in the bones of
peptide pneum-, pneumo- the face that connect to the nasal cavity.
In muscle names, a straight muscle. 2. An expanded portion of a blood vessel, for
Any molecule consisting of two or more amino 1. Prefix relating to air. example the carotid sinus and coronary sinus.
acids joined together, usually in a short chain. 2. Prefix relating to the lungs. reflex
There are many types, some of which are skeletal muscle
important hormones. Proteins are polypeptides: portal vein An involuntary response in the nervous system to
long chains of amino acids. certain stimuli, for example the “knee-jerk” A type of muscle also known as voluntary or
The large vein carrying blood from the intestines response. Some reflexes, called conditioned striated muscle, usually under voluntary control.
peri- to the liver; previously known as the hepatic reflexes, can be modified by learning. Appears striped under the microscope.
portal vein. Many—but not all—skeletal muscles attach to the
Prefix meaning round or surrounding. renal skeleton, and are important in movement of
posterior the body. See also smooth muscle.
peripheral Relating to the kidneys.
Toward the back of the body, when considered in smooth muscle
Toward the outside of the body or to the a standing position. Posterior to, behind. See respiration
extremities of the body. The term peripheral also anterior. Muscle tissue that lacks stripes when viewed
nervous system refers to the whole of the 1. Breathing. under a microscope, in contrast to striated muscle.
nervous system except for the brain and spinal process 2. Also called cellular respiration, the biochemical Smooth muscle is found in the walls of internal
cord. See also central nervous system. processes within cells that break down fuel organs and structures, including blood vessels,
In anatomy: a projection or extended part of a molecules to provide energy, usually in the the intestines, and the bladder. It is not under
bone, cell, etc. presence of oxygen. conscious control, but controlled by the
autonomic nervous system.
peristalsis progesterone retina
somatic
A wavelike contraction of muscles, produced by A steroid hormone produced by the ovaries and The light-sensitive layer that lines the inside of the
muscular tubes, such as that which propels placenta, which plays a role in the menstrual cycle eye. Light falling onto cells in the retina stimulates 1. Of or relating to the body, e.g. somatic cells.
digested food through the gut, or urine through and in the maintenance and regulation of the production of electrical signals, which are 2. Relating to the body wall.
the ureters, for example. pregnancy. transmitted to the brain via the optic nerve.

489
GLOSSARY

3. Relating to the part of the nervous system superior maintains male body and behavioral the outside of the body; in men it also conveys
involved in voluntary movement and sensing characteristics. semen during ejaculation.
the outside world. Higher up the body, when considered in a standing
position. See also inferior. thalamus uterus
somatosensory
supination Paired structures deep within the brain, forming a The womb, in which the fetus develops during
Related to sensations received from the skin and relay station for sensory and motor signals. pregnancy.
internal organs, including senses such as touch, The rotation of the radius around the ulna in
temperature, pain, and awareness of joint the forearm, turning the palms of the hand to thorax vascular system
position, or proprioception. face upward or forward. The opposite to
pronation. In muscle names, supinator indicates The chest region, which includes the ribs, lungs, The network of arteries, veins, and capillaries that
sperm a muscle having this action, e.g. the supinator of heart, etc. conveys blood around the body.
the forearm.
A male sex cell (gamete), equipped with a long thrombus vaso-
moving “tail” (flagellum) to allow it to swim suprarenal glands
toward and fertilize an egg in the body of the A stationary clot in a blood vessel, potentially Prefix relating to blood vessels.
female. Colloquially the word is also used to See adrenal glands. interfering with circulation. Thrombosis is the
mean semen. process by which such a clot is formed. vein
suture
sphincter thymus A vessel carrying blood from the tissues and
1. A stitched repair to a wound. organs of the body back to the heart.
A ring of muscle that allows a hollow or tubular 2. A rigid joint between two bones, as between A gland in the chest composed of lymphoid tissue.
structure in the body to be drawn closed (e.g. the the bones of the skull. Largest and most active in childhood, its roles ventral
pyloric sphincter and anal sphincter). include the maturation of T-lymphocytes.
sympathetic nervous system Relating to the front of the body, or the bottom
spinal cord thyroid gland of the brain.
See autonomic nervous system.
The part of the central nervous system that An endocrine gland located at the front of the ventricle
extends down from the bottom of the brain symphysis throat, close to the larynx (voicebox). Thyroid
through the vertebral column, which protects hormones such as thyroxin are involved in 1. Either of the two larger muscular chambers of
it. Most nerves that supply the body originate A cartilaginous joint between two bones, controlling metabolism, including regulating the heart. The right ventricle pumps blood to the
in the spinal cord. containing fibrocartilage. overall metabolic rate. The hormone calcitonin, lungs to be oxygenated, while the stronger-
which helps regulate the body’s calcium, is also muscled left ventricle pumps oxygenated blood
spleen synapse secreted by the thyroid. to the rest of the body. See also atrium.
2. One of the four cavities in the brain that
A structure in the abdomen composed of A close contact between two nerve cells (neurons) tissue contain cerebrospinal fluid.
lymphoid tissue. It has various roles, including allowing signals to be passed from the end of the
blood storage. first neuron on to the next. Synapses can either Any type of living material in the body that venule
be electrical (where the information is transmitted contains distinctive types of cells, usually together
starch electrically) or chemical (where neurotransmitters with extracellular material, performing a specific A very small vein, carrying blood away from
are released from one neuron to stimulate the function. Examples of tissues include bone, capillaries.
A plant carbohydrate made up of long, branched next one). Synapses also exist between nerves muscle, nerve, and connective tissue.
chains of glucose molecules linked together. and muscles. vertebra (pl. vertebrae)
trachea
stem cell synovial joint Any of the individual bones forming the
The windpipe: the tube leading between the vertebral column or spine.
A cell in the body that can divide to give rise to A lubricated, movable joint, such as the knee, larynx and the bronchi. It is reinforced by rings
more cells. This could be either more stem cells, elbow, or shoulder. In synovial joints the ends of cartilage to keep it from collapsing. villi (sing. villus)
or a range of more specialized types of cell. Stem of the bones are covered with smooth cartilage
cells contrast with highly specialized cells, which and lubricated by a slippery liquid known as tract Small, closely packed, fingerlike protrusions on
play specific roles in the body, and which may synovial fluid. the lining of the small intestine, giving the surface
have lost the ability to divide completely—such An elongated structure or connection that runs a velvety appearance and providing a large
as nerve cells. systemic through a certain part of the body. In the central surface area, which is essential for the absorption
nervous system, the term is used instead of nerve of nutrients.
steroids Relating to or affecting the body as a whole, not for bundles of nerve fibers that connect different
just one part of it. The systemic circulation is the body regions. virus
Substances that share a basic molecular sturcture, blood circulation supplying all of the body apart
consisting of four rings of carbon atoms fused from the lungs. translocation A tiny parasite that lives inside cells, often
together. Steroids, which may be naturally consisting of only a length of DNA or RNA
occurring or synthetic, are classified as lipids. systole 1. Transport of material from one part of the body surrounded by protein. Viruses are much smaller
Many of the body’s hormones are steroids, to another. than cells, and operate by “hijacking” cells to
including estrogen, progesterone, testosterone, The part of the heartbeat where the ventricles 2. A type of mutation in which a chromosome, make copies of themselves. They are unable to
and cortisol. contract to pump blood. or part of one, becomes physically attached to replicate by themselves. Many viruses are
another chromosome or to a different part of dangerous pathogens.
striated muscle tarsal the original chromosome.
viscera
A muscle with tissue that presents a striped 1. Relating to the ankle. transmitter
appearance under a microscope. Striated muscle 2. One of the bones of the tarsus, the part of Another term for organs. The adjective visceral
includes skeletal muscles and cardiac (heart) the foot between the tibia and fibula, and See neurotransmitter. applies to nerves or blood vessels, for example,
muscle. See also smooth muscle. the metatarsals. that supply these organs.
umbilical cord
sucrose temporal vitamin
The cord that attaches the developing fetus to the
See sugar. Relating to the temple—the area on either side of placenta of the mother, within the uterus. Blood Any of a variety of naturally occurring substances
the head. The temporal bones are two bones, from the fetus passes through blood vessels that are essential to the body in small amounts,
sugar one on each side of the head, that form part of inside the cord, transporting nutrients, dissolved but which the body cannot make itself and so
the cranium. The temporal lobes of the brain are gases, and waste products between the placenta must obtain from the diet.
1. Commonly used foodstuff, also called sucrose. located roughly below the temporal bones. and the fetus.
2. Any of a number of naturally occurring voluntary muscle
substances that are similar to sucrose. They are tendon urea
all carbohydrates with relatively small molecules, See skeletal muscle.
in contrast to other carbohydrates that are A tough fibrous cord that attaches one end of a A small nitrogen-containing molecule formed in
macromolecules, such as starch. muscle to a bone or other structure. See also the body as a convenient way of getting rid of vulva
aponeurosis. other nitrogen-containing waste products. It is
sulcus (pl. sulci) excreted in the urine. The outer genitalia of females, comprising the
testis (pl. testes) entrance to the vagina and surrounding
One of the grooves on the folded outer surface ureter structures.
of the brain. See also gyrus. Either of the pair of organs in men that produce
male sex cells (sperm). They also secrete the sex Either of two tubes that convey urine from the zygote
superficial hormone testosterone. kidneys to the bladder.
A cell formed by the union of two gametes at
Near the surface; superficial to, nearer the testosterone urethra fertilization.
surface than. (Opposite term: deep.)
A steroid hormone produced mainly in the The tube that conveys urine from the bladder to
testes, which promotes the development of and

490

INDEX

Index acute lymphoblastic leukemia alcohol cont. anatomy cont. anatomy cont.
(ALL) 459 liver disease 359, 466 immune and lymphatic urinary system 80–81
Page numbers in bold indicate system 182–3
main treatments of a topic. Adam’s apple 123, 409 aldosterone 389, 391, 410 muscular system 174–7 ancestors, human 14–15
adaptive immunity 346, 348–9 alimentary canal see digestive nervous system 178–9 anconeus muscle 207, 211, 227,
A addiction, substance abuse 442 reproductive system 192–5
Addison’s disease 483 system skeleton 168–73 229
A-delta fibers, pain information adduction 34 allergies 460–61 brain 104–15 androgens 389
321 adductor brevis muscle 57, 246, cardiovascular system 68–71 aneurysm 456
allergic rhinitis 460 cells 20–21
abdomen and pelvis 273 anaphylaxis 460 digestive system 78–9 berry 437
arteries 71 adductor compartment of thigh angiodema 460 eyes 116–17 angina 452
cardiovascular system 180–1 asthma 450 head and neck angiodema 460
digestive system 184–9 51, 53 atopic eczema 422 cardiovascular system 124–7 angiograms
immune and lymphatic system adductor longus muscle 57, 242, conjunctivitis 446 digestive system 130–31
182–3 contact dermatitis 422 endocrine system 132–3 arteries of abdomen and legs 71
muscles 174–7 246, 273 food 460 lymphatic and immune coronary arteries 339
nervous system 178–9 adductor magnus muscle 57, 244, rhinitis and sinusitis 448 system 128–9 angioplasty 452
reproductive system 192–5 urticaria 423 muscular system 98–103 angular artery 124
skeletal system 168–73 246, 248, 273 alopecia 425 nervous system 104–21 angular gyrus 106
terminology 30 adductor muscles 239, 272 alveolar bone 48 respiratory system 122–3 angular vein 125
adductor pollicis muscle 57, 229 alveolar nerve, inferior 115 skeletal system 88–95 animals, zoonoses 421
abducent nerve 114, 116 adductor tendons 247 alveolar process of mandible 91 hip and thigh anisotropic fibers, muscle 58
abduction 34 adductor tubercle 237, 239 alveolar sac 151 cardiovascular system 254–7 ankle 45
abductor digiti minimi muscle adenine, DNA 16–17 alveoli 151 lymphatic and immune bones 261
adenoids 129, 345 gas exchange 326–7 system 258–9 joint 41, 48, 262
226, 227, 267 adenoside diphosphate (ADP) 20 journey of air 324, 325 muscular system 242–9 radiographs 45
abductor pollicis brevis muscle adenosine triphosphate (ATP) 20 lung disorders 449, 450 nervous system 250–53 sprains 431
mechanics of breathing 328 skeletal system 236–41 ankylosing spondylitis 428
227 muscle function 290, 291 surfactant 329 joints 288 annular ligament of the radius 203
abductor pollicis longus muscle and pain 311, 321 Alzheimer’s disease 411, 439 lower arm and hand annular tendon, common 116
adhesive capsulitis 432 amacrine cells, retina 314 cardiovascular system 232–3 annulus fibrosus, intervertebral
56, 229 adipocytes 23 amino acids muscular system 226–9
abnormal presentation, baby in adipose cells 22 cell transport 21 nervous system 230–31 disks 48
insulin and 384 metabolism 362–3 skeletal system 222–5 anorexia nervosa 443
uterus 479 adipose tissue 23 pituitary hormones 387 lower leg and foot antagonistic muscles 292–3
abscesses fat storage 363 processing in liver 359 cardiovascular system 270–71 anterior arch, vertebrae 140
hormone production 391 protein synthesis 17 muscular system 264–7 anterior fissure, spinal cord 65
brain and spinal cord 438 adolescence 408–9 in small intestine 356 nervous system 268–9 anthrax 421
liver 467 adrenal glands 80, 85 water-soluble hormones 384 skeletal system 260–63 antibiotics, resistance to 420
accessory nerve 114, 115, 120, 121 Addison’s disease 483 amniocentesis 416 lymphatic and immune antibodies 77
acetabulum 236, 238 aging 410 amniotic fluid 379, 381 system 74–7
acetaminophen 311 blood pressure control 391 amniotic sac 381, 398, 399 muscular system 50–59 antibody-mediated response
acetylcholine 301, 339 blood vessels 180 amebiasis 421 nervous system 60–65 349
Achilles tendinitis 55, 431, 435 Cushing’s syndrome 483 amphetamines 442 reproductive system 82–3
Achilles tendon 262, 263, 265 triggers for hormone release ampulla, balance 316 shoulder and upper arm in blood 334
achondroplasia 417, 483 amygdala cardiovascular system 216–19 and blood types 335
acinar cells 390 385 emotional responses 442 immune system 220–21 in breast milk 405
acne vulgaris 423 adrenocorticotropic hormone limbic system 307 muscular system 204–11 in colostrum 379
acoustic meatus memory and emotion 306 nervous system 212–15 complement system 347, 349
external 118, 119, 316 (ACTH) 385, 386 taste and smell 319 skeletal system 198–203 fertility problems 373
internal 93, 95 adulthood 395, 410–11 amylase 352, 356 skeletal system 40–47 gut flora 361
acoustic neuroma 445 adventitia, blood vessels 340, 341 anabolism 362 skin, hair and nail 38–9 immunization 421
acromegaly 483 aerobic respiration, muscles 291 anemia 458 terminology 30–33 in pregnancy 401
acromioclavicular ligament 202 Africa, human ancestors 14–15 anaerobic respiration, muscles 291 thorax to sperm 477
acromion of scapula 42, 98, 198, age spots, skin 411 anesthetics 311 cardiovascular system 154–7 antidiuretic hormone (ADH) 369,
aging 394, 410–11, 412 in labor and birth 380 digestive system 162–3
200, 202, 203, 204, 210 agoraphobia 443 anal canal 79, 184, 192, 193 immune and lymphatic 387, 391
acrosomes, sperm 372, 376 AIDS 421, 475 anal sphincters 192, 193, 361 systems 160–61 antifungal drugs 421
actin 58, 59, 290, 291 air, respiratory system 324–31 anal warts 475 muscular system 142–7 antigens
active diffusion, cell transport ala of sacrum 169 analgesia, in labor and birth 380 nervous system 148–9
albinism 417, 424 anaphylaxis 460 reproductive system 164–5 adaptive immunity 348, 349
21 albumin 358 anastomoses 218 respiratory system 152–3 antigen-presenting cells (APCs)
active immunity 346 alcohol anatomy skeletal system 136–41
acute bronchitis 449 abdomen and pelvis 348, 349
alcohol abuse 442 and blood types 335
cardiovascular system 180–81 antihelix, ear 119
digestive system 184–9 antioxidants 389
antitragus, ear 119
anus 79, 195
defecation 361
hemorrhoids 465
sphincters 192, 193, 361
anxiety disorders 442

491
INDEX

aorta 70, 162, 163, 180 arm cont. artery cont. artery cont. arthroplasty 428
abdominal 80, 181, 191 skeletal system 40, 42, right 156, 157, 159 middle cerebral 126 articular cartilage 287, 288
aneurysm 456 198–203, 222–3 deep brachial 217, 219 occipital 124
arch of 68, 70, 155, 156, 157 dorsal 194 ophthalmic 126 in childhood 286
ascending 155 armpit 30 dorsalis pedis 271 palmar digital 233 knee joint 49
bifurcation of 181 hair 281, 409 digital 233 peroneal (fibular) 69, 71, 270 articular eminence 92
blood circulation 340 external carotid 68, 70, 124, 125, plantar articular processes, vertebrae 141,
cardiac cycle 337 arrector pili muscle 39, 279 126 lateral 271
coarctation of 454 arrythmias 453 external iliac 68, 70, 180, 181, medial 271 289
descending 68, 70, 155 arterial ligament 156 190, 254, 256 pontine 126 articular surface, joints 47
MRI 196 arteries 25, 68–9, 340–41 facial 124 popliteal 69, 71, 255, 257, 270, arytenoid cartilage 123
genicular 271 aspergillosis 421
aortic bodies, monitoring angioplasty 452 lateral inferior 255, 257, 270 posterior auricular 124 assisted delivery 479
breathing 330 around brain 126 lateral superior 255, 257 posterior cerebral 126 association areas, brain 106
arteriovenous malformation 437 medial inferior 255, 270 posterior circumflex humeral asterion 90
aortic nodes, lateral 74, 182, 259 atherosclerosis 452 medial superior 255, 257 216, 218 asthma 422, 450
aortic valve, heart 159, 336, 337 blood pressure 341 gonadal 70, 180, 181 posterior inferior cerebellar 126 astigmatism 447
apes 12–13 in bones 43, 287 gluteal posterior interventricular 157, astrocytes 298
apex, external arteries of head 124 right superior 180 159 astronauts 287
nerve structure 64–5 hepatic 180, 358, 359 posterior tibial 69, 71, 270, 271 atheroma, thrombosis 456
heart 156, 157 peripheral vascular disorders humeral pulmonary 70, 154, 155, 337, atherosclerosis 452
lung 152, 153 anterior circumflex 216, 218 340
Apgar score, newborn babies 404 456–7 posterior circumflex 216, 218 left 152, 156, 157, 167 aging and 394
aphthous ulcers 462 polyarteritis 461 ileocolic 180 left inferior 167 and stroke 436
aplastic anemia 458 structure 72–3 iliac right 153, 156, 157, 158 athlete’s foot 421, 423
apnea, obstructive sleep 325 umbilical cord 401 common 68, 70, 81, 180, 181 right inferior 166 atlas 42, 44, 140
aponeuroses 51 see also artery and specific external 68, 70, 180, 181, 254, radial 68, 70, 217, 219, 232, 233 intervertebral disks 48
apoptosis 348–9, 410 256 radial collateral 217, 219 atoms, body composition 24
appendicitis 465 arteries internal 68, 70, 180, 181, 256 radial recurrent 217, 219 atopic eczema 422
appendicular skeleton 284 arterioles 39, 77, 340 inferior labial 124 rectal, superior 181 atria, heart 154, 157, 158
appendix 79, 184, 187, 361 artery, inferior mesenteric 68, 70, 181 renal 68, 80, 180, 181, 190, 191, cardiac cycle 336–7
appetite 389, 391 inferior ulnar collateral 217, 219 196, 366 atrial fibrillation (AF) 453
aqueous humor 117 angular 124 infraorbital 124 right coronary 156, 157, 159 atrioventricular (AV) node 338
arachnoid granulation 113 anterior cerebral 126, 303 internal carotid 68, 70, 124, 125, right superior gluteal 180 atrium 166–7
arachnoid mater anterior circumflex humeral 216, 126 spinal, anterior 126 nose 122
brain 113, 302 internal cerebral 303 splenic 181 audiograms 317
spinal cord 65, 303 218 internal iliac 68, 70, 180, 181, submental 124 auditory cortex 305, 308, 316, 317
subarachnoid hemorrhage anterior interventricular 156, 190, 256 subscapular 216, 218 auditory nerve 316, 317
interosseous 232 subclavian 68, 70, 154, 155, 157, aura
437 157, 159 intercostal 154 216 epilepsy 439
arcuate ligaments anterior tibial 69, 71, 270 interventricular superior cerebellar 126 migraine 437
anterior tibial recurrent 270 anterior 156, 157, 159 superior labial 124 auricle, ear 118, 119
lateral 162 auricular posterior 124 posterior 157, 159 superior mesenteric 68, 70, 181 auricles, heart 154, 155, 156, 157
medial 162 axillary 68, 70, 216, 218 labial superior ulnar collateral 217, 219 auricular artery, posterior 124
median 162 brachial 68, 70, 217, 218, 232, inferior 124 sural 255, 257 auricular nerve
arcuate line 175 superior 124 temporal, superficial 124 greater 115
Ardipithecus kadabba 14 233 lateral inferior genicular 255, thoracoacromial 216 posterior 115
Ardipithecus ramidus 14 deep 217, 219 257, 270 thyroid, superior 124 auricular vein, posterior 125
areola 164 lateral plantar 271 tibial auriculotemporal nerve 115
breastfeeding 405 buccal 124 lateral superior genicular 255, anterior 69, 71, 270 Australopithecus afarensis 14
in pregnancy 379 carotid 70, 125, 166 257 posterior 69, 71, 270, 271 Australopithecus africanus 14
Aristotle 70 left coronary 158 tibial recurrent Australopithecus anamensis 14
arm common 68, 121, 124, 126, marginal 156 anterior 270 Australopithecus garhi 14
anterior surface of 30 154, 155, 157 maxillary 124 ulnar 68, 70, 217, 219, 232, 233 Australopithecus sediba 14
cardiovascular system 68, medial cerebral 303 ulnar collateral autism 417
external 68, 70, 124, 125, 126 medial inferior genicular 255, inferior 217, 219 autoimmune disorders 460–61
216–19, 232–3 internal 68, 70, 124, 125, 126 270 superior 217, 219 alopecia 425
chronic upper limb syndrome cerebellar medial plantar 271 ulnar recurrent 217, 219 ankylosing spondylitis 428
posterior inferior 126 medial superior genicular 255, umbilical 405 celiac disease 464
430 superior 126 257 vertebral 124, 125, 126 Crohn’s disease 464
development in embryo 399 cerebral 340 mental 124 dermatomyositis 461
extensor compartment 52 anterior 126, 303 mesenteric 180 arthritis encephalitis 441
flexor compartment 50, 54 internal 303 inferior 68, 70, 181 arthritis mutilans 428 Graves’ disease 482
growth and development 406 medial 303 superior 68, 70, 181 psoriatic 428 multiple sclerosis 440
limb joint disorders 434 middle 126 septic 428 myasthenia gravis 430
lymphatic and immune system posterior 126 polyarteritis 461
circumflex 157 polymyositis 461
220–21 common carotid 68, 121, 124,
muscles 204–11, 226–9, 292–3 126, 154, 155, 157
nervous system 62, 212–15, common iliac 68, 70, 81, 180,
181, 191
230–31 communicating
posterior surface of 32 anterior 126
posterior 126
coronary
left 158

492

INDEX

autoimmune disorders cont. bacteria cont. birth defects 416 blood vessels cont. bowels see colon; large intestine
sarcoidosis 450 infections 347, 420 birthmarks 404, 422 cerebrovascular disorders Bowman’s capsule 366, 367
scleroderma 461 phagocytosis 347 biting 352 436–7 brachial artery 68, 70, 217, 218,
systemic lupus erythematosus role in colon 361 blackheads 423 in eye 314
(SLE) 461 in stomach 187, 354 bladder 80, 81, 190, 191, 194, fetal development 400, 405 232, 233
vitiligo 424 hair 38 deep 217, 219
bacterial meningitis 441 368–9 in kidneys 366 brachial plexus 60, 62, 121, 212,
autonomic nervous system (ANS) balance 310, 316 cystitis 468 in liver 358
61, 84, 296–7 during labor 380 lymph nodes 77 214
labyrinthitis 444 male anatomy 192, 193 newborn baby 405 brachial veins 68, 70, 217, 219
digestion 355 Ménière’s disease 445 MRI 197 in penis 373 brachialis muscle 54, 56, 205, 207,
and limbic system 307 baldness 425 nerve signals 368 peripheral vascular disorders
and muscles 59 ball joints 289 size 368 456–7 208, 209, 211, 226, 228
thermoregulation 279 barium meal 187, 357 stress response 389 in placenta 379, 399, 405 brachiocephalic trunk 68, 70, 154,
autosomes 18 barrier immunity 346 tumors 469 protection 285
axial skeleton 284, 285 basal cells, epidermis 39, 278, 280 urination 368 in skin 278 157
axilla 30 carcinoma 424 blastocysts 376, 379, spread of cancer 419 brachiocephalic veins 68, 70, 154,
see also armpit basal ganglia 112 structure 72–3
axillary artery 68, 70, 216, 218 and movement 309 398–9 thermoregulation 279, 341 155, 167
axillary nerve 60, 62, 212, 214 basal metabolic rate (BMR) 388 bleeding umbilical cord 401, 405 brachioradialis muscle 50, 56, 205,
axillary nodes 74, 76, 160, 161 bases, DNA 16 vascular dementia 439
anterior 220 basilar membrane 316, 317 bruises 424 see also cardiovascular system 209, 210, 211, 226, 227, 228
apical 220 basilic vein 68, 216, 217, 219, 232, clotting disorders 459 bradykinin 311, 321
central 220 in early pregnancy 478 body composition 24–5 brain
lateral 221 233 menstruation 375 body hair 281
axillary tail 164 basiocciput 93 skin repair 278 body mass index (BMI) 481 aging 411
axillary vein 216, 218 basophils 345 see also blood; hemorrhage body system 26–7 anatomy 104–15
axis 42, 44, 140 “belly button” 405 blepharitis 446 bodybuilders 291 appearance 106
intervertebral disks 48 “the bends” 327 blind spot, retina 117, 314 boils 425 basal ganglia 112
axons 22 benign tumors 418 blindness 446 bolus, food 352, 353 blocking pain 311
axon hillock 298 benzodiazepines 442 blisters bone marrow blood vessels 68, 303
classification of neurons 65 berry aneurysm 437 impetigo 422 cardiovascular system 126–7
how neurons work 298, 299, beta thalassemia 458 scalds 424 aplastic anemia 458 caudate nucleus 112
biceps aponeurosis 205, 226 blood 334–5 blood cell production 77, 285, central nervous system 296,
301 biceps brachii muscle 50, 56, 205 blood-testis barrier 373
information processing 304 blood types 335 334 304–5
length 64 contractions 291 carbon dioxide levels in 330, fetal development 401 cerebrovascular disorders
nerve structure 296 long head of 204 leukemia 459
spinal cord 65 muscle mechanics 293 334 lymphatic system 345 436–7
azygos vein 70, 155, 156, 163 origins and insertions 292 cardiovascular system 27, stem cells 22 control of breathing 330–31
short head of 204 transplants 459 control of heart 339
B biceps femoris muscle 245, 264, 158-9 bones 286–7 death 412
clotting 278, 334, 346 achondroplasia 417 disorders 438–9
B lymphocytes 272–3 components 334 blood vessels 43 fetal development 399, 400, 402
adaptive immunity 348, 349 long head of 244 disorders 458–9 composition 45 fornix 112
generation of 345 short head of 249 hormones in 384 densitometry 427 general disorders 440
biceps tendon 203, 205, 226 kidney functions 366–7 disorders 426–9 growth of 406
babies bicornuate uterus 476 plasma 334, 347 endocrine disorders 483 hearing 316–17
congenital heart disease 454 bicuspid valves respiratory system 66–7 exercise and 287 hippocampus 112
developmental milestones 407 heart 158-9 role of liver 358 fractures 44–5 Huntington’s disease 417
fetal development 400–403 lymphatic system 344 as transport system 334 growth 286–7, 406 infections 441
growth of bones 286–7 bile 79, 187 triggers for hormone release growth hormone and 386, information processing 302,
newborn babies 404–5 functions 356
premature babies 479 manufacture in liver 358 385 387 304–5
skull 48, 286 bile duct 188, 189, 359 blood cells see red blood cells; healing 426 internal capsule 112
biliary colic 467 joints 285, 288–9 left-right division 304
back disorders 432–3 bilirubin 358, 359 white blood cells muscle attachments 56–7 lentiform nucleus 112
backbone see spine gallstones 467 blood clots see thrombosis muscle mechanics 292–3 “live” brain scans 305
bacteria jaundice 466 blood pressure 341 nerves 43 lobes 104
biological rhythms 385, 389 ossification 286–7, 404 memory and emotion 306–7
antibiotic resistance 420 biopsy, skin 424 hormone control 391 osteoporosis 410, 411 mental health disorders 442–3
antibody-mediated response bipennate muscles 59 hypertension 455 remodeling 287 motor cortex 112
bipolar cells, retina 314 preeclampsia 478 spongy bone 23 and movement 308–9
349 bipolar disorder 442 pulmonary circulation 71 structure 46–7 MRI scan 62
in appendix 361 bipolar neurons 65 systemic circulation 71 tumors 429 nerve fiber tracts 305
barrier immunity to 346 birth 380–81 blood sugar levels see also skeletal system and nerve tissue 23
complement system and 347 cerebral palsy 438 diabetes 480 neurons 298, 301
friendly bacteria 347 labor disorders 479 regulation of 390, 480 specific bones nutrition 303
blood vessels 340–41 optic radiation 112
in bone 43, 46, 287 and pain 311
in brain 303 pituitary tumors 482
protection 285, 302
sense of touch 320–21

493
INDEX

brain cont. bursitis 434 cancer cont. cardiovascular system cont. cells cont.
size of 104 buttocks thyroid 482 lower leg and foot 270–71 hormones and 384
somatosensory cortex 305, 320, treatment 419 muscles and 27 liver 358–9
321 muscles 176 uterine 471 shoulder and upper arm 216–19 lymphocytes 75
stress response 389 terminology 32 thorax 154–7 metabolism 20
synesthesia 310 Candida albicans 421, 474 tissues 24–5 muscle 58–9
taste and smell 318–19 C canine teeth 131, 352, 406 see also blood vessels; heart nails 281
vision 312–15 canker sores 462 neurons 106, 298–301
C fibers, pain information 321 cannabis 442 carotid arteries 70, 125, 166 replacement 25
brain stem café au lait spots 422 capillaries 69, 340–41 common 68, 121, 124, 126, 154, sperm 372, 373
anatomy 62, 104 calcaneal tendon 57, 262, 263, 155, 157 stem cells 413
control of breathing 330 and active immunity 346 external 68, 70, 124, 125, 126 tissues 23, 24
information processing 302 273 bruises 424 internal 68, 70, 124, 125, 126 tumors 396
medulla oblongata 105 calcaneal tuberosity 263 gas exchange 326, 327 types of 22
and pain 311 calcaneocuboid ligament 262 in kidneys 73, 366, 367 carotid bodies, monitoring see also red blood cells; white
calcaneofibular ligament 262, 263 lymphatic system and 344 breathing 330 blood cells
Braxton-Hicks contractions 378, calcaneonavicular ligaments 262 in muscles 58
380 nasal cavity 324 carotid canal 92 cellular respiration 20
plantar 263 network 151 carpal ligaments cellulose 362
breast cancer 19, 418, 470 calcaneus 41, 43, 261, 262, 263, in small intestine 356 cement, tooth 48, 131
metastases 439 structure 72–3 palmar 225 central executive, brain 306
265, 267, 272–3 in thyroid gland 132 radiate 225 central nervous system (CNS)
breastbone see sternum calcitonin 384 capitate 222, 223, 224, 225 carpal tunnel syndrome 230, 430,
breasts 82, 164–5 capitate bone 234 296, 302–5
bone remodeling 285, 287, 388 capsular layer, sutures 48 434 central sulcus 104, 105, 106
breastfeeding 386, 387, 405 production of 388 carbohydrates carpals 40, 42, 234 centrioles, cells 20
lumps in 470 triggers for release 385 digestion of 356, 362 centromeres 21
lymphatic system 160, 161 calcitriol 280, 388 hormone regulation 388 fractures 44 cephalic vein 68, 70, 216, 218,
in pregnancy 378, 379 calcium carbon, body composition 24 carpometacarpal joint 224, 225
in puberty 409 bone remodelling 287 carbon dioxide carpometacarpal ligaments 224 220, 232, 233
breathing hormone control 388 in blood 330, 334, 340 cartilage 23, 27, 45 accessory 232, 233
control of 147 metabolic disorders 483 gas exchange 326–7 cerebellar arteries
instinctive breathing 330–31 osteoporosis 410, 411 instinctive breathing 330–31 in childhood 406 posterior inferior 126
journey of air 324–5 storage in bones 45, 285 respiratory system 26, 67, 324 in ear 118 superior 126
mechanics of breathing 26, triggers for hormone release carbonic acid 330 growth plate 47 cerebellar cortex 309
carbuncles 425 intervertebral disks 140 cerebellar hemisphere 108, 109
328–9 385 carcinogens 419 joints 48, 49, 286, 287, 288 cerebellar nuclei 309
muscles 26 calculi 468 carcinoma see cancer in nose 98 cerebellar vermis 109
see also respiratory system calf muscle 33, 51, 249 cardiac conducting system 338 ossification 45, 286 cerebellum 62, 104, 105, 107, 111,
breech presentation, baby 479 calories 362 cardiac cycle 336–7 osteoarthritis 411, 428
bregma 88 calyx, kidney 190, 191 cardiac impression, lung 152, 153 in pregnancy 379 135
Broca, Pierre 305 cambial layer, sutures 48 cardiac muscle 24, 59, 336–7 structure 47 fissures 108, 109
Broca’s area 305 cancellous bone 47 cardiac notch trachea 325 functions 309
Brodmann, Korbinian 305 cancer 394, 418–19 lung 151, 152 catabolism 362 information processing 302
Brodmann numbers, cerebral stomach 186 cataracts 411, 446 memory 306
bladder 469 cardiac sphincter 355 cauda equina 60, 62, 63 and movement 309
cortex 305 bone 429 cardiac veins caudate nucleus 112–13, 306 cerebral aqueduct 111
bronchi 67, 150, 151 brain 439 great 156 cavernous sinus 127 cerebral arteries
bronchioles 324, 150, 151 breast 470 middle 157 cecum 79, 184, 187, 360, 361 anterior 126, 303
bronchitis 449 causes 419 small 156, 157 cell-mediated response, immune blood circulation 340
bronchus cervical 471 cardiomyopathies 455 internal 303
colorectal 465 cardiotocograph (CTG) 380 system 348–9 medial 303
journey of air 324 defenses against 346, 348 cardiovascular system 27, 332–41 cells 20–25 middle 126
left main 152 esophagus 462 abdomen and pelvis 180–81 posterior 126
right main 153 Kaposi’s sarcoma 475 anatomy 68–71 aging 394, 410 cerebral cortex 134–5
superior lobar 153 kidney 469 blood 334–5 anatomy 20–21 forming memories 307
brow ridge 88 leukemia 459 blood vessels 72–3, 340–41 blood supply 334–5 functional maps 305
bruises 424 liver 467 cardiac cycle 336–7 body composition 24–5 information processing 302
BSE 441 lung 439, 451 causes of death 413 bone 287 and pain 311
buccal artery 124 lymphomas 459 controlling the heart 338–9 cancer 394, 418, 419 cerebral fossa, lateral 104,
buccal node 128 ovarian 471 disorders 452–5 capillary walls 73
buccinator muscle 56 pancreas 467 gas exchange 326–7 cell division 21 107
bulb, hair 38 prostate 473 head and neck 124–7 cell transport 21 cerebral hemispheres 104, 106
bulbospongiosus 195 screening for 418 hip and thigh 254–7 death 348–9, 410, 419
bulimia nervosa 443 skin 278, 424 lower arm and hand 232–3 DNA 16–17 left-right division 304
bundle-branch block, heart spread of 419 eggs 374 cerebral palsy 438
stomach 463 embryo 398 cerebral peduncle 107
rhythm disorders 453 testicular 472 energy sources 363 cerebral veins 127
bundle of His 338, 339 epidermis 278, 280
bunions 435 fertilization of egg 376–7, 398 blood circulation 340
burns 424 growth, renewal, and repair 362
bursas, knee joint 49, 266 hair 281

494

INDEX

cerebrospinal fluid (CSF) cholesterol cont. coccygeal nerve 63 conception 376–7, 378, 396, 398 corpus callosum cont.
brain 111, 113, 302 micelle 335 coccyx 42, 140, 141, 168, 170, 192, concha, ear 119, 123 functions 304
epidural anesthetics 311 and vitamin D synthesis 280 genu of 110, 112
functions 303 193, 197 inferior 122 splenium of 111
head injury 438 chondrocytes 23, 47 facet joint 141 middle 122
hydrocephalus 438 hyaline cartilage 288 pain 44 superior 122 corpus cavernosum 193
lumbar puncture 441 cochlea 118, 119, 316, 317 conchae, nasal 324 corpus luteum 195, 374, 379
production of 298, 303 chondromalacia 435 labyrinthitis 444 concussion 438 corpus spongiosum 193, 194, 373
spinal cord 65, 303 chondrosarcoma 429 cochlear duct 316, 317 condoms 474 cortex
chordae tendineae 158, 336 cochlear nerve 119, 316, 317 condyles 90
cerebrovascular disorders 436–7 chorionic villi 399 celiac disease 464 condyloma acuminate 475 brain 106
cerebrum 62, 108, 111 choroid 117, 314 celiac nodes 183 cone cells, retina 22, 314 hair 38
choroid plexus 113 celiac trunk 70, 180, 181 confluence of sinuses, brain 127 kidney 366
information processing 302, cognitive abilities, dementia 439 congenital heart disease 454 cortical bone 46
305 of the third ventricle 111 “cold air” headache 437 congenital hip dysplasia 427 corticospinal tract 305
chromatin 17 cold sores 420 congestion, nasal 324 corticosteroid hormones
left-right division 304 chromosomes colds 324, 420, 421, 448 conjunctiva 116, 117 endocrine disorders 483
longitudinal fissure 108, 109 colic, biliary 467 conjunctivitis 446 functions 389
cervical nerves 60, 62, 63, 120, 121 cell division 21 colitis, ulcerative 464 connective tissue 23, 24 triggers for release 385
sense of touch 320 disorders 416, 430 collagen 23 aging 410 cortisol
cervical nodes 76 DNA 17 in cartilage 47, 289 ankylosing spondylitis 428 and aging 410
deep 74 in egg 22 tendons 292 fascia 51 diurnal cycles 385
superficial 74, 128 human genome 18–19 collapsed lung 328, 451 ligament disorders 431 functions 389
cervical spine 90, 140 inheritance 396 collar bone see clavicle rheumatoid arthritis 429 costal cartilage 40, 44, 136, 143
curvature 140 karotype 18 collateral ligaments scleroderma 461 coughing 325, 331
radiographs 44 sex-linked inheritance 397 elbow 203 consciousness 302 bronchitis 449
cervical vertebrae 42, 44, 89, 103, in sperm 22, 372 fibular 266 constipation 464 Cowper’s gland 194, 373
chronic bronchitis 449 hand 224 constrictor muscle, inferior 103 cramp 291
121, 140 chronic obstructive pulmonary medial 266 contact dermatitis 422 cranial bones 96–7
cervix 83, 192, 195, 375, 376 colliculus contact lenses 447 cranial nerves 60, 61, 62, 63, 106,
disease (COPD) 449 inferior 111 contractions
cancer 418, 471 chronic upper limb syndrome superior 111 muscles 290–91 114–15, 121, 296
cervical screening 471 colon 79 uterus 379, 380–81 cranium 40, 302
fertility problems 477 430 ascending colon 184, 187, 196 convex lens, eye 312
labor and birth 380–81, 479 chyme 354, 355, 356 colorectal cancer 465 copper fractures 44
in pregnancy 379 cilia descending colon 185, 196, 360 in blood 334 protective role 285
cesarean section 380, 479 functions 361 storage in liver 359 sutures 88, 90
chalazia 446 in bronchi 151 hepatic flexure of 184 coracoacromial arch 203 see also skull
cheek bone see zygomatic bone epithelial cells 22 hormone production 391 coracoacromial ligament 202, creativity 407
chemicals fallopian tubes 374 movement in 361 cremaster muscle 373
body composition 24 respiratory system 318, 325 sigmoid colon 185, 360 203 Creutzfeldt-Jakob disease 421,
nociceptors 321 ciliary body 117, 447 splenic flexure of 185 coracobrachialis muscle 56
chemoreceptors, control of ciliary ganglion 116 transverse colon 184, 360 coracoclavicular ligament 202 441
ciliary muscle 313 ulcerative colitis 464 coracohumeral ligament 202 cribriform plate of ethmoid bone
breathing 330 ciliary processes 312 colorectal cancer 465 coracoid process 198, 202, 203
chemotherapy, cancer treatment cingulate gyrus 110, 135, 306, 307 colostrum 379, 405 cornea 117 93, 122
cingulate sulcus 106 color cricoid cartilage 102, 122, 123
419 circadian rhythms 132 color blindness 417 conjunctivitis 446 cricopharyngeus muscle 103
chest see thorax circle of Willis 126, 303 color vision 314 laser eye treatment 447 cricothyroid membrane 123
chewing 352 circular breathing 328 genetics of eye color 397 light refraction 312 crista galli 93
circular muscles 59 language and 315 coronal plane 34–5 Crohn’s disease 464
muscles 100 circumflex artery 157 skin 280 coronal suture 88, 90 crown, tooth 131
chickenpox 420, 441 cirrhosis, liver 359, 466 comedones 423 coronary arteries cruciate ligaments
children 394, 406–7 cisterna chyli 74, 182, 183 commissure, anterior 110 angiogram 339
clavicle 40, 42, 89, 136, 142, 166, communicating arteries heart attack 453 anterior 241
growth disorders 483 anterior 126 right 156, 157 posterior 241
hip disorders 427 198, 200, 202, 204, 212, 214 posterior 126 coronary ligament 188 crying, newborn babies 405
chimpanzees 12 fractures 44, 426 communication, facial muscles 98 coronary sinus 157, 158 CT (computed tomography) scans
common ancestor with humans clinodactyl of fingers 416 compact bone 46, 47 coronary thrombosis 453
clitoris 192, 195, 376 complement system 346, 347, coronoid fossa 199 34–5, 71
13 clonal selection, adaptive coronoid process 222 cubital fossa 30
DNA 18 349 corpora cavernosa 194, 373 cubital nodes 74
skeleton 13 immunity 348, 349 compound joints 49 corpus albicans 195, 374 cubital vein, median 217, 219,
skull 13 clotting 278, 334, 346 computed tomography (CT) 34–5, corpus callosum 108, 109, 112–13,
chin 89 232
chlamydia 471, 473, 474 disorders 459 71 135 cuboid bone 261, 262
Chlamydia trachomatis 474 see also thrombosis body of 110 cuneiform bone
chloride, in colon 361 club foot 435
choana 92 clubbed nails 425 intermediate 261
cholecalciferol 280, 391 cluster headache 437 lateral 261
cholesterol coarctation of aorta 454 medial 261, 265
fat-soluble hormones 384 cocaine 442 cupula, balance 316
gallstones 467 coccygeal cornua 141 Cushing’s syndrome 483

495
INDEX

cutaneous nerves depression 442 digestive system cont. diving E
of the arm 212, 214 depressor anguli oris muscle 56, thorax 162–3 “the bends” 327
of the forearm 212, 214 upper digestive tract disorders free diving 330 E. coli 464, 473
of the thigh 178, 250 99, 101 462–3 ear 118–19
depressor labii inferioris muscle dizygotic twins 379
cuticle digital arteries 233 dizziness, labyrinthitis 444 anatomy 445
hair 38 56, 99, 101 digital nerve, dorsal 269 DNA 16–17, 20, 24 balance 316
nails 38, 281 depth, vision 315 digital vein, dorsal 232 bones 97
dermal root sheath, hair 38 dimensions, vision 315 aging 410 disorders 444–5
cystic duct, gallbladder 189 dermatitis, contact 422 diphtheria 421 cancer 419 dominant and recessive genes 19
cystic fibrosis 18, 19, 417 dermatomes, spinal nerves 320 diploid cells 372 cell division 21 fetal development 402
cystitis 468 dermatomyositis 461 disaccharide sugars 356 chromosomes 416 hearing 316–17
cysts 425 dermis 39, 278 diseases and disorders dating species divergence 12 Raynaud’s disease 457
fat-soluble hormones 384 see also hearing
acne 423 hair follicles 281 allergies and autoimmune fertilization of egg 376 eardrum (tympanic membrane)
bone 429 sensory receptors 279 disorders 460–61 genetic profiling 18
breast 470 detoxification, by liver 359 human genome 18 118, 119, 316, 444
epididymal 472 detrusor muscles 191, 368 back, neck and shoulder 432–3 identical twins 379 ear tube, otitis media with
ganglion 434 developmental milestones blood disorders 458–9 “ junk DNA” 18
ovarian 471 bones and joints 426–9 Neanderthals 15 effusion 444
polycystic kidneys 469 407 brain and spinal cord 438–9 sex cells 396 eating disorders 408, 443
cytomegalovirus 475 DEXA scans 427 cancer 418–19 dominant genes 19, 396, 397 ecchymosis 424
cytoplasm 20, 21 diabetes 391, 410, 480–81 cardiovascular disorders 452–5 disorders 417 echocardiography 336
neurons 298 dialysis 469 causes of death 413 dopamine 301 ectoderm 22, 398
cytosine, DNA 16–17 diaphragm 67, 147, 150–51 cerebrovascular system 436–7 Parkinson’s disease 440 ectopic pregnancy 478
cytoskeleton, cells 20, 21 ear disorders 444–5 doppler ultrasound, blood flow 72 eczema, atopic 422
central tendon of 146, 162 endocrine disorders 480–83 dorsal column-medial lemniscus effacement, cervix 379
D hiatus hernia 463 eye disorders 446–7 effector cells, adaptive immunity
left crus of 147, 162 female reproductive disorders tract 304, 305, 320
dartos muscle 373 mechanics of breathing 328–9, dorsal root, spinal nerves 304 348, 349
dating species divergence 12 470–71 dorsal root ganglion 304 efferent ductules 194
daughter cells, cell division 21 331 gene therapy 19 dorsalis pedis artery 271 egg (ovum) 22, 82, 83, 195
de Quervain’s tenosynovitis 430, MRI 197 genetic influences 18–19 dorsum of foot 31
muscular part of 146, 162 general nervous system chromosomes 396
431 right crus of 146, 162 artery of 69, 71 and Down syndrome 416
deafness 445 vomiting 355 disorders 440 Down syndrome 416 ectopic pregnancy 478
death 394, 412–13 diaphysis, bones 46, 286–7 immunization 349 drainage, lymphatic system 344 fertilization 374, 376–7, 396, 398,
diarrhea 464 infectious diseases 420–21 dreaming 402
cell death 348–9, 410, 419 diastole, heartbeat 337 infertility 476–7 drugs 478
death masks 412 diastolic blood pressure 341 inherited disorders 416–17 in-vitro fertilization (IVF) 477
deceleration injuries 438 differentiation, embryo 398 kidney and urinary problems anesthetics 311 infertility 476
decompression chambers 327 diffusion analgesics 311 menstrual cycle 375
deep vein thrombosis (DVT) 456 cell transport 21 468–9 antibiotic resistance 420 ovulation 374
defecation 175, 361 gas exchange 326, 327 liver, gallbladder, and pancreas detoxification by liver 359 ovulation problems 476
defibrillators 339 digastric muscle drug abuse 442 production of 390
dehydration 369 anterior belly of 101 disorders 466–7 Duchenne muscular dystrophy twin pregnancies 379
delivery, assisted 479 posterior belly of 101 lower digestive tract disorders ejaculation 373, 376
deltoid ligament 263 digastric notch 92 430 nocturnal 409
deltoid muscle 50, 52, 54, 56, 204, digestive system 27, 350–63 464–5 ducking reflex 308 problems 477
abdomen and pelvis 184–9 male reproductive disorders ductus arteriosus 405 ejaculatory duct 373
206, 208 anatomy 78–9 ductus venosus 405 elastic cartilage 47
isometric contraction 291 barium meal 187 472–3 duodenum 186, 189, 354 elastin, in cartilage 47
posterior fibers 210 development in embryo mental health disorders 442–3 elbow 203
delusions 442, 443 muscles, tendons and ligaments functions 79, 187, 356 bones 42
dementia 411, 439 398 hormone production 391 chronic upper limb syndrome
dendrites fetal development 402 430–31 MRI 196
cerebellum 309 friendly bacteria 347 nervous system infections 441 peptic ulcers 463 430
melanocytes 278, 280 head and neck 130–31 peripheral vascular disorders release of chyme into 355 disorders 434
neurons 64, 65, 298 hormone production 391 dura mater joint 234–5, 289
dendritic cells 345, 348 large intestine 360–61 456–7 brain 113, 302, 303 electrical activity
dens (odontoid peg), vertebrae 140 liver 358–9 pregnancy and labor 478–9 spinal cord 65, 303 defibrillators 339
dense connective tissue 23 lower digestive tract disorders respiratory disorders 448–51 subdural hemorrhage 437 heart 336, 338
densitometry, bone 427 sexually transmitted diseases dust, in respiratory system 325, nervous system 22, 64, 298,
dental plaque 462 464–5
dentine, tooth 131, 352 mouth and throat 352–3 (STDs) 474–5 329, 331 299, 300–301
deoxyhemoglobin 327 nervous system 296 skin, hair, and nail 422–5 dust mites, allergic rhinitis 460 electrocardiogram (ECG) 338
deoxyribose 16 nutrition and metabolism upper digestive tract disorders dwarfism 417, 483 electroencephalography (EEG)

362–3 462–3 439
small intestine 356–7 disgust 319 electromyography (EMG) 51
smell and taste 319 disks see intervertebral disks elements, body composition 24
stomach 354–5 dislocation, shoulder 203, ellipsoidal joints 288

432
distant vision 313
diurnal rhythms 385, 389
diverticular disease 465

496

INDEX

embolism 456 epicranial aponeurosis 98 Ewings’ tumor 429 eyes cont. feet see foot
pulmonary embolism 451 epidermal ridges, grip 280 exercise Graves’ disease 482 female reproductive system 82
stroke 436 epidermis 39 muscles 116
transient ischemic attack (TIA) and aging 411 myasthenia gravis 430 anatomy 164–5, 192–3
436 protective role 278 effect on bones 287 nerves of the orbit 116 disorders 470–71
renewal of 280 mechanics of breathing 328, 330 photoreceptor cells 22 physiology 374–5
embryo 22, 286, 379, 398–9 epididymis 83, 193, 194, 372, 373 muscles and 55, 291 protection 285 femoral artery 69, 71, 254, 255,
embryonic stem cells (ESCs) 22 cysts 472 exhalation, mechanics of visual cortex 305
emotions 307 epidural space 103, 303 see also vision 256
epidural anesthetics 311 breathing 328–9 deep 71, 254, 256
autonomic nervous system 297 epigastric region 30 expressions, facial 98 F lateral circumflex 254, 256
emotional development 407 epigenetics 396 extension 34 left 181
in puberty 408 epiglottis 66, 78, 102, 122, 123, extensor carpi radialis brevis face medial circumflex 254, 256
and sense of smell 318 angiodema 460 right 180
emphysema 449 129, 130, 134 muscle 227, 229 blood vessels 68 femoral condyles 49, 237, 239,
enamel, tooth 131 coughing 331 extensor carpi radialis longus bones 88–91, 94
encephalitis 441 epiglottitis 448 expressions 98 241, 272
endocarditis, infective 454 swallowing 325, 353 muscle 210, 211, 227, 229 hair 281, 409 femoral nerves 60, 62, 178, 250,
endochondral ossification 286 epilepsy 439 extensor carpi ulnaris muscle 227, muscles 50, 98–103
endocrine system 26, 84–5, epimysium 58, 292 rosacea 423 252
epinephrine 385, 389 229 stroke 54 intermediate 251, 252
382–91 “fight or flight” response 307 extensor compartment lateral 251, 253
disorders 480–83 epiphyseal growth plate 286, 287 facet joints, vertebrae 170, 289 medial 251, 252
glands 388–91 epiphysis, bones 47, 286–7 of arm 52, 235 facial artery 124 posterior 252
head and neck 132–3 episodic memory 306, 307 of leg 51, 55 facial nerve 114, 120, 317 femoral veins 71, 255, 256
hormones in action 384–5 epitheleal root sheath, hair 38 of thigh 51 left 181
pituitary gland 386–7 epithelial cells 22 extensor digiti minimi muscle 227 buccal branch 115 right 180
endoderm 22, 398 respiratory system 325 extensor digitorum muscle 227 cervical branch 115 femur 41, 43, 170, 236
endometrium 192 sense of smell 318 extensor digitorum brevis muscle marginal mandibular branch condyles 49, 237, 239, 241, 272
cancer 471 epithelial tissue 23, 24 epicondyles 237, 239
endometriosis 470 erection, penis 373, 376 57, 267 115 fractures 45
implantation of fertilized egg erection difficulties 472 extensor digitorum longus muscle sense of taste 319 greater trochanter 240, 248,
erector spinae muscles 52, 54, temporal branch 115
379 57, 265, 266, 267 zygomatic branch 115 250, 252
menstrual cycle 375 145, 176 196 extensor digitorum longus tendon facial vein 125 head 197, 236, 238
endoneurium 65 erythroblasts 285 facilitated diffusion, cell transport intertrochanteric line of 240
endoplasmic reticulum 20, 21 erythrocytes see red blood cells 265, 267 knee joint 49, 241
endorphins 311 Escherichia coli (E. coli) 464, 468, extensor digitorum tendons 226 21 lesser trochanter 240
endoscopy 462 extensor hallucis brevis muscle 57, falciform ligament 188 linea aspera 249
endosteal blood vessels 46 473 fallopian tubes (oviducts) neck of 236, 238, 250, 252
endothelium, blood vessels 72, esophageal veins 189 265 patellar surface 237
esophagus extensor hallucis longus muscle anatomy 82, 83, 192, 195 popliteal surface 249, 253
340, 341 blocked 476 shaft 237, 239, 250, 252
energy abdominal 163 57, 266, 267 ectopic pregnancy 478 fertility 394
anatomy 78, 102, 130, 131, 186 extensor hallucis longus tendon fertilized egg in 376 infertility 476–7
adipose tissue 23 cancer of 462 ovulation 374, 376 menopause 410
cell metabolism 20 cells 22 265, 267 false vocal cord 122, 123 problems 373
digestive system 27 gastric reflux 462 extensor indicis muscle 228 falx cerebri 113 sperm 376
muscle contractions 290 muscles 103, 163 extensor muscle, common 56 farsightedness 447 fertilization of egg 374, 376–7, 396,
muscle metabolism 291 swallowing 163, 325, 352, 353 extensor muscles 234, 272 fascia, muscles 51, 58
nutrition and metabolism 362 thoracic part of 162, 163 extensor pollicis brevis muscle 228 fascicles 398, 478
enteric division, peripheral estrogen extensor pollicis longus muscle muscles 58, 290 fetus 378–81, 394, 399, 400–403
functions 390 nerves 65
nervous system 296 menopause 410 56, 229 fat cells 22 fetal monitoring 479
enteroendocrine cells 354 menstrual cycle 375 extensor retinaculum muscle 226, adipose tissue 23 growth and development
environmental factors, epigenetics in pregnancy 379, 401 functions 363
in puberty 408 228 subcutaneous fat 103, 278 problems 479
396 ethmoid bone 318 inferior 265, 267 fatty acids labor and birth 380–81
enzymes cribriform plate of 93, 122 superior 265, 267 digestion of 356, 359, 361, 362 miscarriage 478
crista galli 93 extensor tendons 49, 234 fat-soluble hormones 384 multiple pregnancies 379
barrier immunity 346 orbital plate of 97 extracellular infections 347 hormone regulation 388 placenta 379
cell metabolism 20, 21 ethmoid sinus 122, 123, 324 exytosis, cells 20 insulin and 384 skeleton 47, 286–7
digestive system 362 euphoria 442 eyebrows 281 metabolism 362–3 fibers, muscle 58
metabolism 362 Eustachian (pharyngotympanic) eyelashes 116, 281 fears, phobias 443 fibrin 334
pancreatic 356, 467 eyelids 116 feedback loops 26 fibrinogen 278, 358, 363
in saliva 131, 352 tubes 102, 118, 119, 317 disorders 446 hormone regulation 385 fibroadenosis, breasts 470
in stomach 187, 354 otitis media with effusion 444 skin 278 fibroblasts 23, 278, 426
vitamins and 363 opening of 129 eyes 116–17 fibrocartilage 47, 289
eosinophils 345 evolution 12–15 aging 411 fibrocartilage disk, pelvic girdle
ependymal glial cells 298 albinism 417
epicondyles 42 development in embryo 398, 288
epicondylitis 434 fibrocystic disease, breasts 470
399
diabetic retinopathy 481
disorders 446–7
eye-socket 88
fetal development 400, 402
genetics of eye color 16, 397

497
INDEX

fibroid dysplasia 429 flexor compartment foot cont. frontal sulcus genetics and genes cont.
fibroids 470, 476 of arm 50, 54, 235 fetal development 399, 400 inferior 106 recessive and dominant genes
fibromyalgia 430 of leg 53, 55 gout 429 superior 106 396, 397
fibrosis, interstitial lung disease of thigh 53, 55 grip 280 sex-linked inheritance 397
joint disorders 435 frontal sunis 94
450 flexor digiti minimi brevis muscle MRI 272 frozen shoulder 432 genicular arteries
fibrous capsule 227 muscles 264–7 fungal infections 347, 421 lateral inferior 255, 257, 270
nails 38 lateral superior 255, 257
elbow 203 flexor digitorum longus muscle 57, nervous system 269 ringworm 423 medial inferior 255, 270
knee joint 49 266, 267 plantarflexion 267 fungiform papillae 131, 318 medial superior 255, 257
fibrous joints 48 radiographs 45 fusiform muscles 59
fibula flexor digitorum profundus Raynaud’s disease 457 genioglossus muscle 102
anatomy 41, 43, 262, 263, muscle 56, 57 skeletal system 41, 43, 45, 260– G geniohyoid muscle 102, 130
63 genital herpes 420, 475
270 flexor digitorum profundus skin 278 GABA 301 genital warts 475
fibrous joints 48 tendon 227 tendons 265 gag reflex 352 genitals
fractures 45 venous arch 271 gallbladder 79, 188, 356
head 260, 268 flexor digitorum superficialis newborn baby 404
interosseous border 260 muscle 56, 57, 226, 227 foramina, skull 114 fundus of 184, 189 in puberty 409
knee joint 241 foramen caecum 93, 131 gallstones 467 see also reproductive system
MRI 272 flexor digitorum superficialis foramen lacerum 92, 93 gametes see egg; sperm genitofemoral nerve 178
neck of 260 tendon 227 foramen magnum 14, 92, 93, ganglia germ cells
shaft 260, 261 125 eggs 195, 374
fibular collateral ligament 241, flexor hallucis longus muscle 57, foramen ovale 92, 93, 405 autonomic nervous system 297 sperm 195, 372, 373
267, 272 foramen rotundum 93 sense of touch 320 Geschwind, Norman 305
266 foramen spinosum 92, 93 spinal nerves 296 Geschwind’s territory 305
fibular muscles 53 flexor muscles, 234, 272 ganglion, limb joint disorder 434 gestational diabetes 481
fibular (peroneal) nerve 251, 253 flexor pollicis brevis muscle 227 forceps delivery 380, 479 ganglion cells, retina 314 ghrelin 363
flexor pollicis longus muscle 56, forearm ganglion impar 61 giardiasis 421
common 61, 63, 268, 269 gas exchange 326–7 gigantism 483
deep 61, 268, 269 57, 228 anterior surface 30 gastric glands 354, 355 gingivae 131
superficial 61, 269 flexor retinaculum muscle 227, blood vessels 68 gastric juice 354, 355 gingivitis 462
fibularis (peroneus) brevis muscle bones 40, 222–3 gastric mucosa 354 glabella 88
229, 234 cardiovascular system 232–3 gastric pit 354 gladiolus 40
57, 265 flexor tendons 234 extensor compartment 52 gastric reflux 462 glands 84–5, 388–91
fibularis (peroneus) longus brevis flexor compartment 50, 54 gastric veins 189 see also specific glands
deep 49 MRI 234–5 gastrin 391 glans penis 83, 193, 194
tendon 262 superficial 49 nervous system 230–31 gastritis 463 glasses 447
fibularis (peroneus) longus muscle floating ribs 136 posterior surface 32 gastrocnemius muscles 53, 272–3 glaucoma 446, 447
flu 421, 448 see also arm knee joint 49 glenohumeral ligaments 202
57, 264, 265, 266 fluid balance 369 forensic science 18 lateral head 57, 245, 264 glenoid cavity 198, 200
fibularis (peroneus) longus tendon focusing 313 fornix 112, 306, 307 medial head 57, 245, 264 glial cells 298
problems 447 fossa, muscle attachments 57 muscle mechanics 293 gliding joints 288
267 folia 109 fossils, human ancestors 14–15 gemellus muscles glomerulonephritis 468
fibularis (peroneus) tertius muscle foliate papillae 131, 318 fovea 314 inferior 248 glomerulus
follicle-stimulating hormone (FSH) fractures 44–5, 426 superior 248 kidney 366, 367
57, 267 functions 386 healing 426 genetics and genes 16–19 olfactory epithelium 318
“fight or flight” response 297, 307, menstrual cycle 375, 385 osteoporosis 427 cancer 419 glossopharyngeal nerve 114, 115,
menstrual disorders 470 skull 438 cell types 22
442 ovulation problems 476 free diving 330 diseases 18–19, 416, 417 120, 121
filaments, skeletal muscle 58 in puberty 390, 408 free radicals 389, 394 DNA 16–17, 18 control of breathing 330
filiform papillae 131, 318 and testes 373 frequencies, range of hearing dominant and recessive genes sense of taste 319
fimbriae, fallopian tubes 83, 195, follicles glottis 103
hair 281 317 19 glucagon 390, 480
374 ovarian 195, 374 frontal bone 44, 88, 90, 94, 96 epigenetics 396 glucose
fingers fontanelles 286, 404 and fat-soluble hormones blood sugar levels 480
food 78–9, 131 orbital part of 93 cell metabolism 20
bones 41, 43, 222, 223, 229 allergies 460 zygomatic process 88 384 cell transport 21
clinodactyl of 416 biting and chewing 352 frontal cortex, dorsolateral 308–9 fertilization of egg 376, 396 diabetes 480–81
fingerprints 280, 400 digestion and absorption 356 frontal gyrus gene sequencing 396 digestion of 356
grip 280 food intolerance 460 inferior 104, 106 gene therapy 19 hormone regulation 384, 390
joints 49, 224 hunger 363 middle 104, 106 genetic engineering 19 kidney functions 367
muscles 228 nutrition and metabolism superior 104, 106, 110 genetic profiling 18 maltose 356
nails 281 frontal lobe 104, 108 human genome 18–19 metabolism 362–3
Raynaud’s disease 457 362–3 memory and emotion 306 identical twins 379 muscle metabolism 291
sensory receptors 279, 321 sense of taste 318 frontal nerve 116 inheritance 396–7 processing in liver 359
see also hand in stomach 354–5 frontal pole 104, 106, 107, 108 mutations 396 gluteal artery, right superior 180
first aid swallowing 163, 325, 352–3 frontal sinus 122, 123, 135, 324
muscle, tendon, and ligament vomiting 355
foot
disorders 431 athlete’s foot 421, 423
fixed joints 288 blood vessels 68, 69
flat feet 435 cardiovascular system 270–71
flexion 34 dorsum of 31
flexor carpi radialis muscle 226 eversion 267
flexor carpi ulnaris muscle 50, 56,

211, 228

498

INDEX

gluteal muscles 236 guanine, DNA 16–17 hallux vulgans (bunion) 435 heart cont. high blood pressure see
gluteal nerves 253 gums 131 hamate bone 222, 223, 224, 225, blood circulation 340 hypertension
blood pressure 341, 391
superior 179, 250, 252 gingivitis 462 234 blood supply 339 hilum
gluteal region 32 gut-associated lymphoid tissue hook of 225 cardiac cycle 336–7 lung 152, 153
gluteal tuberosity 238 hamstrings 53, 244, 245, 253, cardiac muscle 59 renal 190, 196
gluten, celiac disease 464 (GALT) 345 cardiovascular disorders 452–5 lymph nodes 345
gluteus maximus muscle 52, 54, gut flora 361 272–3 control of 338–9
gyrus injuries 55, 431 death 412 hinge joints 49, 289
56, 176, 177, 197, 244, 253, hand 394 defibrillators 339 hip
273 angular 106 blood vessels 68 during diving 330
cingulate 110, 306, 307 bones 40, 41, 43, 222–3 echocardiography 336 bone densitometry 427
gluteus medius muscle 50, 52, 56, inferior frontal 104, 106 cardiovascular system 232–3 electrocardiogram 338 cardiovascular system 254–7
176, 197, 246, 248 middle frontal 104, 106 dexterity 407 fetal development 380, 398, 400 disorders in children 427
superior frontal 104, 106, 110 fetal development 399, 400 heart attack 413, 453 joint 237, 289
gluteus minimus muscle 56 lateral occipitotemporal 107 grip 280 heart failure 453 joint replacement 428
glycerol 356 medial occipitotemporal 107 growth and development 406 heart muscle disease 455 lymphatic and immune system
glycogen parahippocampal 107 “hand-arm syndrome” 457 heartbeat 336–7
postcentral 105, 106 joints 49, 224–5 hormone production 391 258–9
hormone regulation of 390, 480 precentral 105, 106 muscles 226–9 hormone regulation 388 muscles 242–9
storage in liver 359, 363 straight 107 nails 38 MRI 166–7 nervous system 250–53
goblet cells 325 supramarginal 106 nervous system 230–31 murmurs 454 skeletal system 42, 236–40
goiter 482 inferior temporal 105, 107 ossification 286 nervous system 26 hippocampus 112, 306, 442
golfer’s elbow 54, 430, 434 middle temporal 105 palmar surface of 31 newborn baby 404, 405 hirsutism 425
Golgi complex 20 superior temporal 105 radiographs 225 position in chest 154 histamine 321
gomphosis, joints 48 Raynaud’s disease 457 protection 285 histone 17
gonadal arteries 70, 180, 181 H repetitive strain injury (RSI) 430 rhythm disorders 453 HIV 420, 421, 475
gonadal veins 70, 180, 181 tendons 226 stress response 389 hives 423
gonadotropin-releasing hormone Haemophilus 441 haploid cells 372 tissues 24 Hockney, David 310
hematoma hard palate 102, 122, 130, 131 valve disorders 454 Hodgkin’s lymphoma 459
(GnRH) 373, 385, 408 swallowing food 353 valves 336 hole in the heart 454
gonads 390 head injury 438 “hat-band” headache 437 homeostasis 385
gonorrhea 471, 473, 474 subdural hemorrhage 437 haustra 187 heartburn 462 hominins 14
goosebumps 279 hemocytoblasts 285 Haversian canal 46 heat see temperature Homo antecessor 15
gorilla 12 hemodialysis 469 hay fever 422, 460 heel-bone 41, 43, 261, 288 Homo erectus 14, 15
hemoglobin 327, 330 head and neck height Homo ergaster 15
skull 13 anemia 458 arteries 70 Homo habilis 15
gout 429 bilirubin 358 baby’s head 406 in childhood 406 Homo heidelbergensis 15
Graafian follicles 374 liver functions 359 brain 108–11 in puberty 409 Homo neanderthalensis 15
gracilis muscle 57, 242, 244, 246, red blood cells 22, 285, 335 cardiovascular system 68, Helicobacter pylori 463 Homo rudolfensis 15
hemophilia 459 helicotrema 317 Homo sapiens 15
273 hemorrhage 124–7 helix homozygous genes 397
gracilis tendon 241 stroke 436 digestive system 130–31 DNA 16–17 horizontal cells, retina 314
granular cells, epidermis 280 subarachnoid 437 endocrine system 132–3 ear 119 horizontal fissure, lung 150, 153
granzymes 348 subdural 302, 437 head injury 438 helminths 421 hormones
Graves’ disease 482 see also bleeding lymphatic and immune system helper T cells 348, 349 aging 410
gravity hemorrhoids 465 hemispheres, cerebral 104, 106, in blood 334
hair 39, 281 128–9 and blood sugar levels 480
and balance 316 aging 410 muscular system 98–103 304 bone remodeling 285, 287
effect on bones 287 albinism 417 MRI 134–5 heparin 321 breakdown of 358
gray matter alopecia 425 nervous system 62, 104–21 hepatic arteries 180, 358, 359 endocrine disorders 480–83
brain 106, 305, 309 facial 409 respiratory system 122–3 hepatic ducts 189 endocrine system 26, 84–5,
spinal cord 65, 304 follicles 39 skeletal system 40, 42, 88–95 hepatic portal vein 189, 358, 359,
great apes 13 functions 281 headache 437 382–91
greenstick fractures 426 growth 281 healing see injuries 362 fluid balance 369
grief 297 hirsutism 425 hearing 310, 316–17 hepatic veins 68, 70, 189 glands 388–91
grip 280 lanugo 402, 404 aging 411 hepatitis, viral 466 hormones in action 384–5
groin 30 nasal hairs 324 auditory cortex 305 hepatocytes 358, 359 and hunger 363
“groin pulls” 247 pubic hair 409 fetal development 402 hepatoma 467 in labor 380
growth and development 394–5 structure 38 hearing aids 445 hernia, hiatus 463 male reproductive system 373
in adolescence 408 and thermoregulation 279 hearing loss 445 heroin 442 menstrual cycle 375
bones 286–7 types of 281 range of 317 herpes viruses 420 pancreas 189
in childhood 406 hair cells, in ear 118, 316, 317 synesthesia 310 pituitary gland 386–7
hormone regulation 387, 388 hair follicles, acne 423 see also ear genital herpes 475 in pregnancy 379, 401
muscles 291 hallucinations 442, 443 heart 25, 68, 69, 70, 156–9 herpes simplex 441, 475 in puberty 408
growth hormone (GH) 386 aging 410, 411 herpes zoster 441 regulation of 385
diurnal cycles 385 artificial heart 337 heterozygous genes 397 rhythms 385
functions 387 hiatus hernia 463 in small intestine 356
growth problems 483
pituitary tumors 482, 483
growth plate, bones 47
growth retardation, fetal 479