anatomy

Somatic Nervous System

Composed of:
1. Somatic afferent (sensory) division
2. Somatic efferent (motor) division

Somatic afferent division conveys sensory information from the skin,
skeletal muscles, tendons, joints, eyes, tongue, nose and ears to
spinal cord and brain via the spinal and some cranial nerves
Somatic efferent division conduct impulse from the CNS to skeletal
muscle

Autonomic Nervous System

Divided into:
a. Sympathetic division
b. Parasympathetic division

Nomally exert antagonistic effects on many of the same targets
organs
ANS main function: To promote homeostasis by regulating visceral
activities, especially activities of cardiac, smooth and gland muscles
Generally, sympathetic division= prepares body for stressful situation
while parasympathetic division= active when body at rest

SYMPATHETIC DIVISION PARASYMPATHETIC DIVISION

the 'fight-or-flight' system, which prepares the 'house-keeping' system, which is in
body to cope with some threats or control most of the time
emergency situation maintains homeostasis by seeing that
include dilated pupils, increased heart normal digestion and elimination occur
and respiratory rates, increased blood and that body energy is conserved
level and sweating include pupillary constriction, increased
sympathetic vasoconstriction shunts blood digestive tract mobility and smooth
while exercise muscles activity leading to elimantion of
urine and feces

THE ENDOCRINE SYSTEM

AN OVERVIEW

THE ENDOCRINE SYSTEM IS A MAJOR
CONTROLLING SYSTEM OF THE BODY

ITS EFFECT ARE MEDIATED BY HORMONES
AND ARE MORE PROLONGED

THROUGH HORMONES, IT STIMULATES SUCH
LONG-TERM PROCESSES AS GROWTH AND
DEVELOPMENT, METABOLISM,
REPRODUCTION, AND BODY DEFENSE

SOME ENDOCRINE ORGANS ARE PART OF
MIXED GLANDS (BOTH ENDOCRINE AND
EXOCRINE IN FUNCTION) E.G : PANCREAS AND
GONADS (OVARIES AND TESTES)

ENDOCRINE GLANDS ARE DUCTLESS, WELL-
VASCULARIZED GLANDS THAT RELEASE
HORMONES DIRECTLY INTO THE BLOOD OR
LYMPH

EXOCRINE GLANDS PRODUCE NONHORMONAL
SUBSTANCES, SUCH AS SWEAT AND SALIVA,
AND HAVE DUCTS

LOCAL HORMONES (PROSTAGLANDINS) ARE
NOT PART OF THE ENDOCRINE SYSTEM ,
WHICH INCLUDE:

AUTOCRINE – ACT ON THE CELL THAT
RELEASED THEM
PARACRINE – ACT ON A DIFFERENT CELL TYPE
NEARBY

ENDOCRINE – INTERACT WITH DISTINCT
TARGET CELL

FUNCTION

CONTROLLING ACTIVITY OF SPECIFIC ORGAN
OR TISSUE IN MAINTAINING HOMEOSTASIS BY
SECRETING HORMONES AS IN :

- REGULATOR OF GROWTH AND DEVELOPMENT
- REGULATING OF CONCENTRATION OF BODY

FLUID (WATER AND ELECTROLYTE)
- METABOLISM OF CARBOHYDRATE, PROTEIN

AND LIPIDS (NUTRIENT)
- ACTS TOGETHER WITH NERVOUS SYSTEM TO

HELP THE BODY TO REACT TO STRESS PROPERLY

HORMONES

CHEMICAL SUBSTANCES SECRETED BY
CELLS INTO EXTRACELLULAR FLUID
(BLODDSTREAM) THAT REGULATE THE
METABOLIC ACTIVITY OF OTHER CELLS IN
THE BODY

ALL HORMONES ARE AMINO ACID-BASED
OR STEROIDS

TYPES OF HORMONES

AMINO ACID BASED (WATER SOLUBLE)

* MOST HORMONES ARE AMINO ACID-BASED

STEROIDS (LIPIDS SOLUBLE)

* SYSTHESIZED FROM CHOLESTEROL
• OF THE HORMONES, ONLY GONADAL AND

DRENOCORTICOL HORMONES ARE
STEROIDS

REGULATION OF HORMONES
SECRETION

> NEGATIVE FEEDBACK

• RESPONSE THAT REDUCES THE INITIATING
STIMULUS (OPPOSITE DIRECTION)

• IMPORTANT IN REGULATING HORMONE LEVELS
IN THE BLOOD

> POSITIVE FEEDBACK

* REINFORCE THE INITIAL STIMULUS

Mechanism of Hormones
Action

-Hormones alters cell activity by stimulating or
inHibiting cHaracteristics cellular processes of tHeir

target cells

MAIN MECHANISM FOR A HORMONE
COMMUNICATES WITH TARGET CELLS

• Amino acid-based hormones and second messenger system
-hormones bind to hormone receptor in the plasma membrane (bind to G
protein) linked to enzyme adenylate cyclase which initiate the conversion of
ATP to cyclic AMP (cAMP)
-cAMP (second messenger) activates protein kinases in the cytoplasm
-protein kinases activated other proteins in the cell
-activated proteins induce changes in the cell

• Steroid hormones and direct gene activation
-diffuse directly through plasma membrane (target cells)
-binds with protein receptor and turns into steroid protein complex
-entering nucleus to a specific DNA region (activating DNA initiates
messenger RNA formation leafing to protein synthesis)
-reaction between steroid-protein complex and DNA activates genes to
synthesize new proteins and enzymes and induce changes in the cell

Hormones - Target cells - Changes in cells activity

CONTROL OF HORMONE RELEASE

• Synthesis and release of most hormones are regulated by negative
feedback system

• Endocrine glands are stimulated to manufacture and release their
hormones by 3 major types of stimuli :
a.Humoral stimuli
b.Neural stimuli
c.Hormonal stimuli

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NURUL NAJIHAH BINTI IDRIS 2022628108 SR1131C

AMONG THE MAIN ENDOCRINE ORGANS IS :

Endocrine Thyroid
organs gland

Pituitary Parathyroid
gland glands

Adrenal Pineal
glands gland

Pancreas

Gonads
(ovaries&
Testes)

Hypothalamus

• PITUITARY GLAND 2. Anterior lobe (adenohypophysis)

➢ Attached to hypothalamus by the • Influenced by hypothalamic hormone
infundibulum within the sphenoid bone • Growth hormone (GH), prolactin

➢ Divided into 2 lobes: (PRL),adrenocorticotropic hormone (TSH), follicle-
stimulating hormone (FSH) and luteinizing (LH)
1. Posterior lobe (neurohypothalamus) • ACTH,TSH,FSH and LH are topic hormones (regulate other
endocrine gland)
• Store hormones from hypothalamus-
oxytocin and antidiuretic hormone (ADH)

Anterior Pituitary Hormones 2. Growth hormone (GH)
1. Prolactin (PRL)
• An anabolic and protein-conversing hormone
• Stimulates production of breast that promotes total body growth
milk (lactation)
• It important effect is on skeletal
muscles and bones

hypothalamus

Pituitary

gland

hypothalamus Growth hormone

2 Adiponectin

Leptin liver

Spinal Posterior Anterior Adipose tissue
cord pitutary pituitary

Mammary Oxytoxin Prolactin muscle bone
gland prolactin (milk
Oxytocin production) insulin
3 (milk
1 letdown)

3. Adrenocorticotropic hormone (ACTH) 4. thyroid-stimulating homone (TSH)

• Stimulate the adrenal cortex to releaseits • Stimulates the thyroid gland to
hormones (mineralocorticoids, release thyroid hormones
glucocorticoids and gonadocorticoids (throxine and triiodothyronine)

5. Gonadotropic hormones ii. Luteinizing hormone (LH)

i. Follicle-stimulating hormones (FSH) • Beginning at puberty, stimulates ovulation
and stimulates ovarian to produce
• Beginning at puberty, stimulates follicle estrogen and progesterone, stimulates the
development and estrogen production male’s testes to produce testosterone
by female ovaries, promotes sperm
production in male

Posterior Pituitary Hormones 2. Antidiuretic hormone (ADH) or vasopressin

1. Oxytoxin • Causes kidney tubule cells to reabsorb
and converse body water and
• Stimulates powerful uterine contractions increased blood pressure by
(trigger labor and delivery of infant) and constricting blood vessels
causes milk ejection in the nursing woman

• Also promote sexual arousal

• THYROID GLAND

• Located on the trachea, just inferior to the larynx (in the anterior throat)
• Thyroid hormone (TH) includes thyroxine and triiodothyronine, which increase the rate

of cellular metabolism
• Calcitonin produced by parafollicular (C) cells in response to high blood calcium

levels. It causes calcium to be deposited in bones

• PARATHYROID GLANDS

• 4 small glands located posterior/dorsal aspect of the thyroid gland
• Low blood levels of calcium stimulate the release parathyroid hormone (PTH)
• PTHcauses bone calcium to be liberated into the blood, the intestine to increase

calcium reabsorption

• ADRENAL (SUPRARENAL) GLANDS

• Lies on top of kidneys
• Divided into:

Adrenal Adrenal
cortex medulla

• Adrenal cortex hormones include: 2. Glucocorticoids (cortisol)

1. Mineralocorticoids (aldosterone) • Enable the body to resist long-term stress by
increasing blood glucose levels and
• Regulate sodium ion (Na+) and depressing the inflammatory response
potassium ion (K+) reabsorption
by the kidneys

• Their release I stimulated by low
Na+ and/or high K+ levels in
blood

3. Gonadocorticoids/Sex hormones Adrenal medulla hormones produce
(androgens) catecholamines (epinephrine and
norepinephrine) in response to
• Responsible for sex drive in female sympathic nervous system
stimulation. Its hormones enhance

and prolong the effects of the ‘fight-
or-flight’ response to short-term strees

• PANCREAS

• Located behind stomach

Composed of both endocrine and exocrine
gland cells

Hormones produced from pancreatic islets (islets
of Langerhans) containing alpha cells
(glucagon) and beta cells (insulin)

Insulin is released when the blood levels of
glucose are high. It increases the rate of glucose
uptake and metabolism by body cells; stimulates
glycogen formation

Glucagon is released when blood levels of
glucose are low, stimulates the liver to release
glucose to the blood

• PINEAL GLAND

Located in the
diencephalon/third
ventricle of the brain

(epithalamus)

Releases melatonin,
which acts as biological

clock; reproductive
behaviour; affects daily
biological rhythms such
as body temperature,

sleep and appetite

• THYMUS GLAND

Located deep Large and
to sternum conspicuous in

infant and
children

Diminishes in Its hormones,
size thymosins, thymic

throughout factor, and
adulthood thymopoeitins, are

important to the
normal development

of the immune
responses (thymosin
promotes maturation
of T lymphocytes in

body defense)

• GONADS

OVARIES
• Ovaries located in

abdominopelvic cavity
• Ovaries release:

1. Estrogen

Release of
estrogens by
ovarian follicles
begins at puberty

(FSH)

With Estrogen stimulate
progesterone, maturation of
female
they cause reproductive
the menstrual
organs and female
cycle secondary sex
characteristics

TESTES

NURATHIRAH EYUNIS BT MOHD HANIFF(2022481644)

BODY WATER CONTENT

50% 60%
WATER WATER

HIGHER
FAT
CONTENT,
LESS
SKELETEL
MUSCLE
MASS

FLUID COMPARTMENT

BODY WATER EXTRACELLULAR

TOTAL BODY WATER INTERSTITIAL FLUID(IF)
40L,60% BODY FLUID BETWEEN THE CELL
INCLUDE INTRACELLULAR FLUID(ICF) IF VOLUME=12L
AND 80% OF ECF
EXTRACELLULAR FLUID(ECF)
PLASMA
INTRACELLULAR FLUID IN THE BLOOD VESSEL
VOLUME=3L
25L,IN CELL 20% OF ECF
LOW NA+ AND CL-
MA JOR CATION : POSTASIUM
MA JOR ANION: HYROGEN
PHOSPHATE

COMPOSOTION OF BODY FLUID

NONELECTROLYTE ELECTROLYTE

ORGANIC (Carbon contain) INORGANIC (NOT Carbon contain)

NOT dissolved in water Dissolved in water

Less osmatic power Greater osmatic power ( electrolytes have greatest
ability to couse fluid shift)

Uncharged Charged(+ -)
Cation +charged ions(Na+)
Anions –charged ions (Cl-)

Glucose,urea,lipids,creatinine Eg, Na+CL-,K+
Inorganic salts,all acids ancd bases and some
proteins

WATER BALANCE

To remain properly hydrated
Water intake must equal water
output(2500ml/day)

Water intake Water output

Thirst mechanism is the driving force for water intake Obligatory water losses from
The hypothalamic thirst center osmoreceptor control
both water intake (thirst) and renal water *breathing,sweating,digestion
conservation through adjustments in the rate of ADH
secretion. *minimum 500ml in urine to

Dehyration excrete wastes

Body didn’t get enough water in body
Symptoms of dehydration
*feeling thirsty
*dark yellow&smelling urine
*feeling dizzy or lightheaded
*feeling tired

ELECTROLYTE BALANCE

What is Electrolyte?
Electrolyte are salts,acids and bases

What is Electrolyte balance?
Electrolyte balance usually refers only to salt balance
 Salts enter the body by ingestion and are lost via perspiration, feces and urine

Central Role of Sodium and Sodium Balance

 Sodium is the most abundant cation(minerals) that the body needs in Extracelullar
 Most of the body’s sodium is located in blood and in the fluid around cells
 The body obtains sodium through food and drink and loses it primarily in sweat and urine
 Control or maintaining blood pressure blood volume
 When either becomes too high, sensors in the heart, blood vessels, and kidneys detect

the increases and stimulate the kidneys to increase sodium excretion, thus returning
blood volume to normal(135-145 mg/dl)
 Na+(sodium) balance is linked to blood pressure and blood volume control mechanisms

Potassium Balance

What is postassium?
Potassium is the third most abundant mineral in the body
Important of postassium:

 It helps the body regulate fluid, send nerve signals and regulate muscle contractions
 Affect resting membrane potential (RMP) in neurons and muscle cells (especially

cardiac muscle)
 Hydrogen ion (H+) shift in and out of cells
 Leads to shift in K+ in the opposite direction to maintain cation balance
 Extracelullar fluid(ECF) K+ levels rise with acidosis, as K+ leaves and H+ enters the

cells and fall with alkalosis, as K+ enters the cells and H+ leaves them to enter the
ECF
 The mineral is also important for a healthy heart, as its movement in and out of cells
helps maintain a regular heartbeat

ACID-BASE BALANCE

What is acid-base balance?

Your blood needs the right balance of acidic and basic (alkaline) compounds to function
properly

 pH affect all functional proteins and biochemical reactions
 Normal pH of body fluids:

 Arterial blood : pH 7.4
 Venous blood and IF fluid : pH 7.35
 ICF : pH 7.0
 Alkalosis or alkalemia: arterial blood pH >7.45
 Acidosis or acidemia: arterial pH < 7.35

Mechanism to Control Hydrogen Ion(H+)

1.Bicarbonate Buffer System

 The bicarbonate buffer system is an acid-base homeostatic mechanism involving the

balance of carbonic acid (H2CO3)

 Act quick temporarily bind hydrogen ion and remove from solution thus raise pH

level

 Mixture of carbonic acid and its salts, sodium bicarbonate

 Buffer ICF and ECF a solution whose function is to minimize the change in pH when

a base or an acid is added to the solution

 The only important ECF buffer

 If strong acid is added:

 Bicarbonate ion (HCO3-) ties up H+ and forms H2CO3

 HCI + NaHCO3 H2CO3+ NaCI

 pH decrease only slightly

 If strong base is added:

 It causes H2CO3 to dissociate and donate H+, then ties up the base

 NaOH + H2CO3 NaHCO3 + H2O

 pH rises only slightly

2.Respiratory Regulation of H+

 Respiratory system eliminates CO2

 A reversible equilibrium exists in the blood:

 CO2 + H2O H2CO3 H++HCO3-

 During CO2 unloading the reaction shifts to the left (and H+ is incorporated into H2O)

 During CO2 loading the reaction shifts to the right (and H+ is buffered by proteins)

SKELETAL SYSTEM

SKELETAL CARTILAGE

STRUCTURE TYPES GROWTH

1.Made of cartilage tissue • Hyaline Cartilages Within (Interstitial
• Elastic Cartilages growth=growth from inside)=
2.Contains large amounts of water • Fibrocartilages increase in length
(resilience/flexible)
New cartilage tissue at the
3.No nerves fibers periphery (appositional growth)
= increase in width
4.Surrounded by a fibrous
perichondrium (contain blood
vessels) that resists expansion

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TYPES OF CARTILAGE

Hyaline Cartilages • Network of collagenous fibers, translucent (glassy)
Provide support with flexibility and resilience
• The most abundant(plenty) skeletal cartilages form most of
• early skeleton

Elastic Cartilages • Contain more elastic fibers, in addition to collagen fibers

• Provide more flexible than hyaline cartilage and lightweight
support

Fibrocartilages • Contain thick collagen fibers
• support and protection, highly compressible and has great

tensile strength

CLASSIFICATION OF BONES

FLAT BONE IRREGULAR BONE

- Thin, flattened, a bit - Complicated shapes
curved
e.g: verterbrae, facial
e.g: ribs, sternum, skull bones, hip bones
bones, scapulae

SHORT BONE LONG BONES

- Cube shapes - Length greater than width
- Composed of a diaphysis (shaft)
e.g : carpals, tarsals, patella and two epiphyses (ends)
(sesamoid bone= form in a - All limbs bones are long bones
tendon)
except patella, carpals & tarsals

e.g : humerus, radius, ulna, femur,
phalanges

Function Of Bones

The foundation of your skeletal system are your
bones. They are extremely strong yet lightweight
structures. Around 206 bones make up the body
of an average adult.

The structure that holds the body together is only
one function of bones. Bones are available in a
variety of forms and functions. This article
describes their functions:

I. Support; The framework for the connection
of muscles and other tissues is provided by
bones. For example, when you're standing
up, your upper body is supported by the
larger bones in your legs. Without our bones,
we’d have no defined shape.

II. Protection; Internal organs are shielded from
harm by bones like those in the skull and rib
cage. Your ribs, for example, secure your
heart and lungs, while your skull protects
your brain.

III. Bones serve as levers and places of
attachment for muscles, enabling the body to
move. Tendons connect your muscles to
your bones. Your bones serve as a lever and
your joints as a pivot point when your
muscles contract. Your body can move in a
variety of ways because of the interaction of
your bones and muscles.

IV. Mineral storage; Calcium and phosphorus,
which are necessary minerals for a variety of
cellular processes throughout the body, are
stored in bones.

V. Hematopoiesis, or the process of making
blood cells, takes place in the red marrow
that can be found inside the cavities of some
bones. Lipids, including as fats, are a source
of energy that are kept in reserve in the
yellow marrow's adipose cells.

BONE STRUCTURE

-Consist of trabeculae filled with red (inner)
or yellow marrow.

-Withstand stress, shock absorber,
and support shifts in weight.

-Weaker and more flexible than
compact bone

-Forms outer shell of a bone. (outer)

-Very hard and dense.

-Provide strength and protection to
bones.

-Storing calcium

-The structural unit of it called:
Osteon or Harversian system.

-The osteon consists of: a central
canal surrounded by concentric
lamellae of bone matrix.

-Osteocytes, embedded in lacunae,
are connected to each other &
central canal by canaliculi.

BONE MARROW

RED BONE MARROW YELLOW BONE MARROW
-Produces blood cells (hematopoiesis) -Stores fat
-Stem cells in your red bone marrow -2 types of stem cells in
(hematopoietic stem cells) create red & white blood yellow bone marrow:
cells and platelets, all of which are components of (adipocytes & mesenchymal
whole blood. stem cells)
-They preserve fat for
Energy production &
Develop bone, cartilage,
Muscles & fat cells for body

A fracture is a broken bone. It will heal whether or not a physician resets (places)
it in its anatomical position. If the bone is not reset correctly, the healing process
will rebuild new bone but keep the bone in its deformed position.
When a broken bone is manipulated and set into its natural position without
surgery, the procedure is called a closed reduction. Open reduction requires
surgery to expose the fracture and reset the bone. While some fractures can be
minor, others are quite severe and result in grave complications.

Types of Fractures

Fractures are classified by their complexity, location, and other features (Figure 6.5.1). Table
6.4 outlines common types of fractures. Some fractures may be described using more than
one term because it may have the features of more than one type (e.g., an open transverse
fracture)

.

Figure 6.5.1 – Types of Fractures: Compare healthy bone with different types of fractures:
(a) open fracture, (b) closed fracture, (c) oblique fracture, (d) comminuted fracture, (e) spiral
fracture , (f) impacted fracture, (g) greenstick fracture, and (h) transverse fracture.

Types of Fractures (Table 6.4)

Type of fracture Description

Transverse Occurs straight across the long axis of the bone

Oblique Occurs at an angle that is not 90 degrees

Spiral Bone segments are pulled apart as a result of a twisting motion

Comminuted Several breaks result in many small pieces between two large segments

Impacted One fragment is driven into the other, usually as a result of compression

Greenstick A partial fracture in which only one side of the bone is broken, often occurs in the young

Type of Fracture Description

Open (or compound) A fracture in which at least one end of the broken bone tears through the skin; carries a
high risk of infection

Closed (or simple) A fracture in which the skin remains intact

TYPE OF MUSCLE
TISSUE

(MUSCULAR SYSTEMS)

TYPES OF MUSCLE TISSUE

Skeletal muscle

The specialized tissue that is attached to bones and allows movement.
Together, skeletal muscles and bones are called the musculoskeletal
system (also known as the locomotor system). Generally speaking,
skeletal muscle is grouped into opposing pairs such as the biceps and
triceps on the front and back of the upper arm. Skeletal muscles are
under our conscious control, which is why they are also known as
voluntary muscles. Another term is striated muscles, since the tissue
looks striped when viewed under a microscope.