Human Body Encyclopedia

Life cycle Life expectancy

Growing older As a general rule, the
bigger a creature is, the
Adults keep growing, but more longer it lives. So how long
slowly than children. When you do humans live?
get older, your body takes longer
to repair itself and replace Butterflies have very short
worn-out cells. lives. Many live for only a
month or two.

Cats kept as pets live
longer than wild ones – up
to 15 years.

People can live for 100
years. Women generally
live longer than men.

Tortoises can live for 150
years. Some spend a quarter
of their lives asleep.

Twenties Thirties
During your twenties you are at your peak. Because they’re not growing any
Your body has reached its adult size so you more, many people need to eat
don’t spend most of your energy on growing. less so they don’t get fat.
Most bodies are strong and
A normal, healthy Brittle bones healthy, but athletes
spine holds the body With old age, the bones and disks in are already past
straight. the spine get weaker and thinner, so their best.
people get a little bit shorter.

The spine starts Eventually, it
to weaken.  forms an “s”
curve and the
head moves
 forwards.

104 What is the longest a person has ever lived?

Smile lines Growing older

With age, skin Silver surfer
gets less stretchy
and will not Today people
smooth out when live longer than
you relax your ever thanks to
face. This is gives advances in
you wrinkles. medicine. A
Many cultures healthy diet,
respect wrinkles exercise, and
as signs of wisdom a young mind
and experience. can make old
age a happy
time.

Old age

Papery skin, weak bones, stiff joints, and

Middle age bad eyesight are common in old people.

Organs and muscles are starting to Most of the organs including the
get weaker. Skin on the face gets
wrinkly, and hair starts to go lungs and heart don’t work As you get older, your
grey. Women stop as well as they used to. hair contains less
having babies. melanin – the

substance that gives it
its colour.

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Keeping healthy Proteins
Meat, fish, eggs,
What’s in food? beans, and nuts
contain protein.
People eat to get energy. Your body needs
You need a variety protein to repair
of foods to keep its cells.
your body
in peak Carbohydrates
working Bread, cereal,
condition. pasta, and sweet
foods are mostly
A balanced diet means carbohydrates.
eating everything your You need them to
body needs. give you energy.

Fat
Nuts and dairy
foods, such as
butter and cheese
contain fat. You
only need small
amounts of fat.

Takeaways and fizzy
drinks are nice as a
treat but no substitute
 for a good meal.

Eat your greens Junk food
Fast foods like hamburgers and
Fresh fruit and vegetables are crammed chips contain unhealthy amounts
with vitamins and minerals. Your body

needs these to stay healthy. of fat and salt, and few vitamins.

106 What is a vegetarian?

Water You need about What’s in food?
Your body is six glasses of 
two thirds liquid every day Allergies
water, but but some of this
you’re losing can come from If your body reacts
water all the your food. badly to a certain food
time. You could and makes you ill, you
live for several may be allergic to it.
weeks without
food but only Wheat isn’t good for some
for about 3 days people. They cannot eat
without water. normal bread.

Sunshine food Nuts can be dangerous – 
even in tiny quantities – 
You need vitamin if you have a nut allergy.

D for strong bones. Food  Cows’ milk doesn’t suit
It is found in fish gives  some people, but they can
and eggs, but drink sheep or goats’ milk.

your body can  you Become
an expert...
produce it when energy.
you get sunlight on chewing food,
pages 86-87
on your skin.
on making urine,
pages 90-91

Fuel for your body
An orange gives you enough
energy to cycle for 5 minutes.
A chocolate bar gives you
enough energy to
cycle for 45
minutes.

The amount of energy you
get from food is measured
in calories.

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Keeping healthy

Sleep Adults need 24
about seven
hours sleep.

18 6

When you sleep your body rests. 12

Your brain stops dealing with things

in the outside world, and uses this

time to sort out the events of the day.

24 6
18

12

A three year How much sleep?
old needs
about As we grow older we
12 hours sleep. need less sleep. Young
adults need about eight
24 hours, while over 60s
may need only six.
18 6

12

A newborn baby can sleep
 for 20 hours a day. By six
months, 15 hours is usually
enough.

Sleep patterns

Throughout the night, Awake Th      d  o  t s sho w  
you move in and out of 
shallow and deep sleep Shallow sleep e    y e   l l o  w
several times. As the hours
pass, sleep gradually 9 10 11 12 1
becomes lighter until
you wake up.  T Deep sleep

i              What is insomnia?

m   

e     

f       

o    

r   b    
e d    

.

108

Dreaming Sleep

Everyone dreams. When Nightmares
Nightmares are scary
you dream, your eyelids dreams that can wake
flicker. This is called you up and make you
feel frightened or sad.
roarpRiEdMey, eslmeeopv.ement , .p  o s s i b le! During nightmares,
. people often think
they are being chased
  o  u d  r eam a   or bullied.
n   
What dreams mean
y   ..   n            s i      g     n  i     h  t y 
People are fascinated by
   e what dreams mean. We
don’t know for sure but...
     h
Everyone Flying can mean that
you feel powerful and
dreams, but not free of problems.
    W everyone
remembers their Being naked sometimes
means you are afraid of 
dreams. being weak.

Falling may mean you
feel out of control or are
scared of losing something.

  w  h  e n yo   u  d r   e   a m. Sleep walking

During deep sleep, parts

23456 of the brain stay awake.
People may talk, or get up
G    

o    and walk around. They
o   
usually don’t remember
d   

m or   ni n g  !  they have done this. 109

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Keeping healthy

Doctors and dentists

When you are ill you visit
the doctor. First, the doctor
examines you. Next, the
doctor prescribes treatment or
medicine to make you better.

The examination

The doctor asks you about your
symptoms and then looks at and
listens to different parts of your body.

Say “ah” Ears, nose, and throat
The doctor uses a stick Doctors use an otoscope to examine your
to hold your tongue ears, nose, and throat. Swelling or itchiness
down and look at may mean you have an infection.
your tonsils. If 
your tonsils often
get infected you
may need an
operation to
remove them.

It is your tonsils’ job Hear, hear
to stop germs Doctors use an instrument
getting down your
throat. called a stethoscope to
listen to your heartbeat
What is a paediatrician?
or to hear how well
your lungs are working.

110

Doctors and dentists

Tools of the trade Eye spy

Doctors keep a few simple Opticians test your
instruments in their sight and work out
surgeries to help them whether you need
examine their patients. glasses. They test

A stethoscope allows each eye separately
the doctor to listen to your because often one
heart or your breathing.
These funny can see better than
A rubber hammer is glasses help the the other. Your
banged against your knee optician find eyesight changes
to test your reflexes. out exactly so you need to get
how well your your eyes tested
An ophthalmoscope has eyes work.
a bright light for looking at
the back of your eyes. every year.

Syringes are used to give Open wide
people injections to stop
them getting some diseases. You can look after your teeth by
brushing them, but you should
Medicine comes from a still get them checked twice a
pharmacy. The doctor just year by a dentist. Hopefully,
gives you a prescription. you won’t need any fillings.

Brace yourself  111
Orthodontists are dentists
who straighten out crooked
teeth. They do this by fitting
your mouth with braces to
push your teeth gradually
into the right position.

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Communication

Body language

You don’t just talk with words – you also use your
hands, face, and body. The look on your face and the
way you stand can say a lot about how you really feel.

Personal space Only best friends and
family can enter the
People show how well they close intimate zone.
know each other by how close
they stand or how often they The intimate zone is
touch. It’s rude to stand too where people who know
close to a stranger but normal you well can stand
to stand close to a best friend. while talking to you.

The social zone is The personal
where strangers stand zone is for people
while talking to you. who know you but
aren’t close, such
as teachers.

These girls are Copying
copying each Good friends often mimic each
other’s body other’s body language without
realizing. They might walk in
language. step, sit or stand in the same
position, or copy each other’s
hand movements.

Who’s in charge? This boy’s
One of the things people relaxed posture
signal with their body is shows he feels
whether they’re in charge very confident.
or somebody else is in
112 charge. Leaning forwards
or looking relaxed are
ways of appearing to be

in charge.

How does a dog show it knows you’re in charge?

Open or closed? Body language
When someone feels relaxed or Learning gestures
friendly, they have an “open”
posture, with arms and legs apart. You pick up a lot of your
If someone is nervous or awkward, body language from the
they have a “closed” posture, with people you grow up with.
arms and legs close to the body. Your gestures and the way
you sit, stand, and walk
are probably similar
to your friends
and family.

Boys often learn
their gestures from
older brothers,
and girls pick up
many of theirs
 from older sisters.

Talking to animals

Animals can’t understand speech

but they often understand our Become
body language. Dogs can sense
an expert...
who’s in charge from body

language. They need to be on muscles and

treated strictly or will movement,

start to misbehave. pages 26-27

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Communication Speak to the hands

Use your hands Hands seem to have minds
of their own. When people
Most people move their
hands as they speak, but talk, their hands move all
what do their gestures over the place, even when
mean? Some hand they’re on the phone!
gestures mean the
same thing all over Making a circle
the world, but A finger touching a thumb
others vary from means “OK” in North America,
place to place. “worthless” in France, and “I
want my change in coins”
Thumbs up in Japan. In Turkey
A raised thumb means “good” it can be rude.
or “well done!” in North America. In
Germany it means “one”, in Japan it
means “five”, and in the Middle East
and Africa it’s impolite.

Palms together Shaking hands
This is a sign of prayer Shaking hands is
in Christian countries, a common greeting
but in India it is used in many countries,
as a greeting. Indians but there are slight
place their hands differences. A firm
together, make handshake is a sign
a slight bow, of sincerity in Europe
and say but is thought to be
Namaste.  aggressive in Asia.

In some countries, In Sicily, this gesture
women never shake combined with a karate
hands with men. chopping movement
means
“I hate you so much”.

114 How does a diver say “shark” underwater?

Making a point Use your hands
Pointing is one of 
the first hand gestures hP oi  nti  ng  wi  th an outstretc ed a r m  mea n s
that people learn, and
it means the same thing g .somethin is fa   r a wa y
all over the world.
Babies ask for things by Become
pointing at them before an expert...
they learn to speak.
on the bones in
your hands,
page 20-21

These 26 signs stand
 for the letters of the
alphabet in British sign
language.

Talking underwater

Divers can’t speak Two fingers on the
underwater so they use palm means the
a kind of sign language letter “n”.

instead. They have special
signs for marine animals

like sharks and turtles.

OK is shown by a Sign language

finger touching a Deaf people communicate
thumb, making a circle. without hearing by reading

Stay at this depth is lips, using facial expressions,
shown by waving a flat or using sign language. Sign
hand from side to side.

Stop is shown by a language varies a lot from
clenched fist and a country to country.

bent arm. 115

 .  d  n  a  h  e   n o   h t  i  w   d   a e  h  e  h t    n o   n i f  s ’   k r  a   h s   a  g  n i  k  a   m   y  B

Communication

Express yourself 

Your face helps you communicate by showing how

you feel. All over the world, people use the same

facial expressions to show

the six main emotions. 2Surprised
When you’re surprised,
Surprise makes your eyebrows shoot
you gasp for breath up, your eyes open wide,
because the hormone and your jaw drops. Some
adrenaline makes your
lungs work faster. people clap the side of 
their face or cover their
mouth as well.

1Happy Grumpy or angry
In a genuine smile, people sometimes
the eyes crease and the
cheeks rise. A smile means look red around the
the same thing whether you eyes.
live in the Sahara desert
or Amazon rainforest.

3Angry
An angry person’s eyebrows
move down, their eyes narrow,
and their mouth closes tightly. They
might also glare without blinking.

116 How many facial expression

are there?

Express yourself 

Baby face

Babies communicate Become

with their faces an expert...

before they learn on how babies

to talk. They smile, develop,

frown, and show all pages 100-101

the main emotions.

Babies learn to mirror their parents’ smiles 5Afraid
 from a very early age. Fear raises the eyelids, making
the eyes look white. The mouth
4Sad opens wide in horror, and blood
In an unhappy
face, the mouth may drain from the face,
droops, the inner ends
of the eyebrows go up, making the skin pale.
and wrinkles appear
above the nose. 6Disgusted
Powerful feelings Wrinkles across the nose
of sadness also and narrow eyes are signs
make people of disgust. The sight of disgust
cry. in someone’s face can make

you feel disgusted too.

Babies can’t help crying
when they’re sad, but older
people may hide their tears.

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Reference section

Amazing facts about YOU!

Skeleton Brain and nerves Breathing
and bones
Your brain is the Lungs take air into
Without a body’s control centre. your body so that
skeleton to hold Signals zoom to and life-giving oxygen can
you up, you’d from the brain enter your blood.
collapse on the along your nerves.
ground like a Laid out, the inside of 
heap of jelly. Nerves carry signals your lungs is a third as
at up to 400 kph big as a tennis court.
Your smallest bone is the (250 mph).
stapes in your ear, which  The fastest recorded
is smaller than a rice grain. Your brain is made of  sneeze reached 167 kph
about 100 billion tiny (104 mph).
Weight for weight, bones cells called neurons.
are stronger than steel In one day you breathe in
or concrete.  The left side of your brain enough air to ll 33,000
controls the right side of  drink cans.
A baby has more than your body and vice versa.
300 bones but adults Skin, nails and hair
 The human eye can see a
have only 206. candle ame at night from  The tough, protective
1.6 km (1 mile) away. surface of your body is
Muscles and almost entirely dead.
movement When you’re bored, the
pupils in your eyes get Every four years you
Muscles move your smaller. shed your own body
body by pulling bones. weight in dead skin.
You use hundreds of  Heart and blood
them when you walk. You have about 5 million
Your heart pumps hairs, but only 100,000
Every hair in your body blood around your are on your head.
has a tiny muscle that body. It works nonstop
can pull it upright. without getting tired.  The thickest
skin on your
Your strongest muscle is Your smallest blood body is on the
the masseter (jaw muscle), vessels are ten times soles of your
which closes your mouth. thinner than a hair. feet.

You use more muscles Your body contains
when you frown than enough blood vessels to
when you smile. circle the world twice.

118

Fighting disease Digestive Amazing facts
system Urinary system
Germs are always trying
to get inside you, but Digestion turns Urine gets rid of 
your body fights back. food into simple chemicals that your
chemicals body doesn’t need.
Lassa fever is a very that your
dangerous disease. It kills body can You will make enough
about a fifth of its victims. make into urine in your lifetime
new cells or to fill 500 baths.
Bacteria are so small use for fuel.
that a thousand could Asparagus can turn your
fit on the head of a pin. urine green. Blackberries
can turn it red.

The world’s most The food you eat in Reproduction
common disease is a year weighs as
the common cold. much as a car. The reproductive organs
create new people from
Cancer happens when You make enough spit tiny specks of matter.
your own cells multiply in your lifetime to fill
out of control. two swimming pools.

When you recover from Your digestive glands The most babies born to
an infectious disease, your start working as soon one mother is 69. Most were
body becomes immune to it. as you smell or see food.
twins, triplets, or quads.

Your tongue senses five The first quintuplets
tastes: salty, sweet, sour, known to have survived
bitter, and savoury. infancy were born in 1934.

The smell of poo comes Growth
from a chemical called
skatole. As you grow you slowly
change into an adult,
Each hair on your head but it takes a long time!
grows for about 3 or 4
years and then falls out. The fastest-growing
A new one grows in its part of a baby’s
place. body is its head.

A girl is about three-
quarters of her adult
height at 7 years old.

A boy is about three- 119
quarters of his adult
height at 9 years old.

Reference section

Through the ages

The human body is so amazingly complicated that
it’s taken doctors at least 4000 years to figure out how

it works. Their discoveries have led to
many new ways of curing illness.

460–377 BC 250 BC Egyptian doctors
cut open corpses to find
The Greek doctor out how the body works.
Hippocrates is
sometimes 100 BC Chinese doctors
called the father discover that blood travels
of medicine. He around the body in cycles.
was one of the
first people to 1290 Spectacles are
realize that worn for the first time
diseases have in Venice, Italy.
natural causes
and cures. 1350 Rats spread bubonic
plague in Europe, killing a
Before the time of  quarter of the people.
Hippocrates, many
people thought that 1500 A Swiss pig farmer
diseases were performs the first Caesarian
punishments sent by section on a living person.
the gods.
1596 The Italian scientist
Galileo Galilei invents the
thermometer.

1684 Dutch microscopist
Antony van Leeuwenhoek
discovers blood cells.

1770 The world’s first
comfortable false teeth
are used in France.

1796 English surgeon
Edward Jenner discovers
how to make vaccines.

1816 The stethoscope is
used for the first time.

120 What life-saving antibiotic did Alexander Fleming discover?

Through the ages

.tT o h   f eai  ntIe  tdah ol ii uas  tno hws oc n  wi e sn it   tch  ik  se tosL  tv oa e m zrz aaac nr hdo wSopvoarekrll sa  nza  ni

1818 James Blundell Modern 121
carries out the first medicine
blood transfusion.
Doctors know
1852 Doctors use more about how
bandages soaked in the body works
plaster to make casts. than ever before,
but there are still
1853 Scottish doctor some mysteries,
Alexander Wood like why we
invents the syringe. hiccup or how
the brain works.
1895 Wilhelm Röntgen
accidentally discovers how   .    n  i  l  l  i    c i    n   e    P
to take X-rays of bones.

1928 An English scientist
discovers antibiotics – 
drugs that kill bacteria.

1953 Scientists work out
the structure of DNA, the
chemical that carries genes.

1955 Doctors start using
ultrasound scanners to see
babies inside the womb.

1967 Surgeon Christiaan
Barnard carries out the
first heart transplant.

1971 Brain scanners come
into use, allowing doctors
to study living brains.

1978 Louise Joy Brown,
the first test-tube baby,
is born in England.

Reference section

Glossary

Artery A blood vessel that Enzyme A substance Hormone A chemical

carries blood away from that speeds up a particular produced by one part of the
your heart to the rest of  chemical reaction in the body in order to change the
your body. body. Digestive enzymes way a different part of the
speed up the breakdown body works. Hormones are
Bacteria Tiny one-cell of food molecules. made in glands and carried
by the blood.
creatures found all Epiglottis A trapdoor-like
around us. Some are Joint A connection between
helpful, others cause tag of skin that stops food
diseases. going into your breathing two bones.
tubes when you swallow.
Blood vessel Any tube Mucus Slippery liquid on
Oesophagus The tube
that carries blood through the inside of your nose,
your body. from your mouth that takes throat, and intestines.
food to your stomach when
Capillary The smallest you swallow. Nerves Threads of tissue

type of blood vessel. Your Genes Instructions that that carry high-speed signals
body contains thousands around the body.
of miles of capillaries. control the way your body
develops and works. Genes Nutrients The basic
Cell The smallest living pass from parents to their
children. chemicals that make up food.
unit of your body. Your body uses nutrients for
Germs Tiny living things fuel, growth, and repair.
Diaphragm A strong, flat
that can get into your body
sheet of muscle under and cause illness. Bacteria
your lungs. You use it and viruses are germs.
when you breathe.
Gland A group of 
Digestion The
specialized cells that make
process that breaks and release a particular
down food into tiny substance such as a
pieces that your hormone or enzyme.
body can absorb
and use.

122

Glossary

Organ A group of tissues Reflex A reaction that Urine Waste liquid that

that form a body part is out of your control, passes out of you when you
designed for a specific job. like breathing or blinking go to the toilet. Urine is made
Your stomach is an organ. when something gets near of water and chemicals your
your eyes. body doesn’t need.
Oxygen One of the gases
Saliva The liquid in Vaccination A substance
in the air. You need to
breathe in oxygen to live. your mouth. Saliva helps that is swallowed or injected
you taste, swallow, and to protect your body from
Proteins Vital nutrients digest food. disease.

that help your body build System A group of organs Vein A blood vessel that
new cells. Food such as
meat, eggs, fish, and cheese that work together. Your carries blood towards your
are rich in proteins. mouth, stomach, and heart.
intestines make up your
Receptor A type of nerve digestive system. Vertebra One of the bones

cell that detects a change Tissue A group of cells that link together to form
outside or inside the body, your backbone, or spine.
helping to create one of the that look and act the same.
senses. Touch receptors in Muscle is a type of tissue.  X-rays Invisible rays that
the skin, for example, help
create the sense of touch. Umbilical cord The tube pass through objects. X-ray
photographs show the inside
 joining a baby to its mother’s of your body.
body while it is still
inside her.

123

Reference section

Index

AAdam’s apple, 64 blood groups, 53 copying, 112
adolescence, 103 blood sugar level, 59 coughing, 32, 67
adrenaline, 59 blood system, 10, 48–51, 120 cranium, 14, 15
adults, 104–105 blood vessels, 10, 15, 48–49 crying, 39, 65, 100
air 60–63, 64 body heat, 29, 69, 72 cuts, 56–57, 75
allergies, 80–81, 107 body language, 112–113
alveoli, 61 bone marrow, 18, 54 Ddefences, 76–77
anaesthetic, 33 bones, 9, 18–19, 104, 118 dentists, 111
animals, 5, 13, 42, 44, 71, diabetes, 59
see also skeleton diaphragm, 60, 67
104, 113 braille, 35 digestion, 11, 77, 82–89,
ankles, 13, 23 brain, 15, 25, 30–33, 47,
antibodies, 78, 79 119
aorta, 48, 50 100, 118 disease, 53, 74–75, 119,
arm muscles, 226 and senses, 34, 37, 40,
arteries, 10, 48–49 120
asthma, 80, 81 42–43, 45 dizziness, 47
brain stem, 30 DNA, 7, 8, 121
Bbabies, 53, 65, 79, 100–101 breathing, 11, 33, 60–67, doctors, 110–11, 120
bones, 20 double-jointed, 23
communication, 100, 117 91, 118 dreaming, 109
muscles, 27 bruises, 57 dust mites, 68, 80
newborn, 61, 97, 100, 108
backbone, 13, 16–17, 21, 104 Ccalcium, 18, 19, 59 Ears, 12, 14, 20, 76
bacteria, 75, 76, 77, 85 camels, 93 balance, 46
balance, 30, 46–47 capillaries, 48, 49 hearing, 44–45
baldness, 73 carbohydrates, 106 wiggling, 25
ball and socket joints, 22 carbon dioxide, 60, 62 eggs, 94, 98
bladder, 33, 92–93 cartilage, 14, 17, 20–21 elbows, 23
blind spot, 42, 43 cells, 8–9, 94–95 enamel, 85
blinking, 25, 32, 33, 39 cerebellum, 30 energy, 11, 59, 62, 107
blisters, 57 cerebrum, 30 enzymes, 82, 83, 86, 87
blood, 52–53, 118 chemicals, 5 epiglottis 67
children, 100–102 exercise, 7, 19, 28–29
clotting, 53, 55, 56–57 chimpanzees, 5, 15 eyebrows, 39
colour, 5, 49 coccyx, 16, 17 eyelashes, 75
blood banks, 53 colds, 37, 74 eyelids, 39
blood cells, 52–55, 120 colour blindness, 41 eyes, 6, 7, 38–41, 55, 111
red, 9, 18 colour vision, 40
white, 78, 79 communication, 97, 100, sockets, 14, 39

112–117
contact lenses, 41

124

F face, 6, 14, 15, 27, 64 hayfever, 81 Index
expressions, 27, 116–117 head lice, 73
faeces, 89, 91 hearing, 11, 44–45 125
family, 7, 23, 113 heart, 10, 24, 29, 50–51, 118
fat, 9, 106 height, 7, 21, 104
feet, 11, 12, 13 hiccups, 67
fertilization, 94, 98 hinge joints, 22, 23
fingerprints, 9, 70, 99 Hippocrates, 120
fingertips, 34, 35, 70–71 hips, 22, 23
fixed joints, 22 hormones, 11, 58–59
flexibility, 28, 29 hunger, 33
follicle mites, 75
foetus, 96–97
food, 29, 106–107
food allergies, 81, 107
friends, 102, 112, 113
fungi, 75

Ggenes, 6–7, 98 Iimmune
germs, 11, 52, 55, 74–79, system, 11,
119 78–79, 80
glands, 58, 77, 87 incubators, 61
glasses, 41, 111, 120 insulin, 59
goose pimples, 73 intestines, 11, 24, 75, 77,
grazes, 57
grip, 34 88–89
growth, 58, 100–104, 119 iris, 38, 39
itching, 33, 71
Hhaemoglobin, 54
hair, 11, 72–73, 105, 118 JK jaws, 12,
body hair, 5, 97, 73, 14–15, 22
103  joints, 11, 21,
colour, 6, 73 22–23, 70
follicles, 35, 72–73 keratin, 68, 71, 72
hands, 5, 27, 70 kidneys, 10, 48, 91
knees, 22, 32
bones, 12, 13, 20–22
gestures, 114–115

Reference section

Llanguage, 101, 102 nightmares, 109 plasma, 52
learning, 31, 100, 102 nose, 14, 37, 60, 67 plasters, 57
leeches, 57 nucleus, 8 platelets, 52–53, 55, 56
legs, 11, 24, 29 pollen, 81
lens, 40, 41 Ooesophagus, 87 pores, 69
life expectancy, 104 old age, 104, 105 potty training, 93
ligaments, 23, 27 optic nerve, 40, 42 pregnancy, 96–97
lips, 14, 35, 36 opticians, 111 proteins, 29, 106
liver, 48 organs, 10, 11, 48, 105 puberty, 64, 103
lungs, 48, 60–61, 76, 118 orthodontists, 111 pulse, 51
lymph system, 79 oxygen, 49, 54, 60–63, 67 pupils, 38, 39, 40, 55

Mmacrophages, 78 Ppain, 33, 34 Rreflexes, 32, 87, 111
melanin, 39, 69, 73 pelvis, 12, 17 reproduction, 11, 94–95,
memory, 31 peristalsis, 88 119
mosquitos, 75 personal space, 112 retina 40, 41
motion sickness, 47 pins and needles, 33 ribs, 12, 16, 17
mouth, 11, 60, 76, 82 pituitary gland, 58 ringworm, 75
movement, 11, 12, 30, 118 pivot joints, 23 robots, 5
plaque, 85
detecting, 46
 joints, 22–23
muscles, 24–25
spine, 16, 17
mucus, 67, 76, 77, 89
multiple births, 99
muscles, 11, 24–29, 47, 100, 118
largest, 25
longest, 24
number of, 24
myofibrils, 26

Nnails, 11, 70–71, 118
neck, 12, 16, 23
nephrons, 91
nerves, 9, 11, 32–33, 118

126

Ssaliva, 36, 76, 86 snoring, 65 Index
scabs, 57 sounds, 44, 64–65
scanners, 4, 96, 121 speaking, 30, 65, 101, 102 toes, 35
sclera, 38 sperm, 94 tongue, 7, 25, 36, 86
senses, 11, 30, 34–45 spinal cord, 15, 16, 32 tonsils, 79, 110
sex hormones, 59 spine, 13, 16–17, 21, 104 touch, 11, 34–35
shivering, 29 stamina, 28, 29 trees, 62
sight, 11, 38–43, 111 stethoscope, 110, 111, 120 twins, 98–99
sign language, 115 stitch, 27
skeletal muscles, 24, 26 stomach, 24, 77, 82, 87 Uuniqueness, 6–7, 95
skeleton, 11, 12–13, 118 strength, 7, 28, 29 urethra, 90, 92
skin, 9, 11, 68–69, 118 sun, 69, 107 urine, 90, 91, 92–93
swallowing, 67, 87 urinary system, 11, 90–93, 119
allergies, 81 sweat, 35, 69, 91 uterus, 95, 96–97, 98
colour, 6, 69
sense of touch, 34–35 Ttail bone, 13 Vvaccines, 79, 120
wrinkly, 69, 105 taste, 36–37 valves, 51
skull, 12, 14–15, 22, 31 tears, 39, 76 veins, 10, 48–49, 51
sleep, 27, 32, 59, 100, 108–109 teeth, 5, 14, 18, 84–85, 120 vena cava, 48, 50
sleep-walking, 109 verrucas, 74
smell, 36–37 brushing, 85, 100, 111 vertebrae, 13, 16–17, 104
smiling, 25, 27, 100, 116 temperature, 78 vertebrates, 13
sneezing, 66 tendons, 27 viruses, 74
thigh bone, 13 vitamins, 107
thinking, 11, 30 vocal cords, 64, 67
threadworms, 75 voice box, 64
thumbs, 23
tinea (ringworm), 75 Wwalking, 33, 101
tissues, 9, 10 water, 5, 63, 90–91,
107
skin’s defences, 68, 69
windpipe, 60–61, 64
womb, 95, 96–97, 98
wrinkles, 69, 105
wrists, 12, 23

XYX-rays, 4, 19, 21,
121
yawning, 67

127