YOU AND
YOUR BODY
INVISIBLE ATTACKERS
Our bodies are also under attack by tiny creatures we
can’t see. We only know they are there from their
revolting effects! These can include things like:
Our skin starting to smell,
or even going scaly and
flaking off.
Your body is a bit like a fortress that’s under
siege.Outside is the enemy: tiny organisms that
would really like to get inside, where it’s warm and
comfortable. Normally, you’re good at repelling these
attackers but if they get in all kinds of yuckiness
can start. The body is also a traitor, making plenty
of nasty stuff itself, which is completely normal!
suddenly
Boils and warts
here.
popping everyw
VISIBLE ATTACKERS
There are plenty of tiny creatures that like to make their
home on the outer layer of our bodies. Most are microscopic
but some you can even see: creatures such as head lice
or fleas. These love to make their home on a nice,
warm human. Then, whenever they feel hungry,
they can have a little snack on your blood!
,y
Actually our body
y
l
l
quite g is
a
norm
ood
d
i
n
n
e
g
f
e
d
i
t
t
s
a
elf
against attack.
4
Invisible enemies don’t
only attack the outside of
our bodies. Sometimes they
manage to get right inside.
If this happens, the yuckiness
might include breath that
smells like a blocked drain,
or diarrhoea (uncontrollable,
sloppy pooing) which means
you dare not venture too far
from a toilet.
And if things get really
bad, our flesh starts
to go rotten!
YUCK!
5
HEAD LICE
AND NITS
Imagine if an uninvited
guest moved in, to live
among the hairs on your
head. Not good – but it
gets worse. This guest
lives by tapping in through
your skin and drinking
your blood! It’s a head
louse: easy to catch
but tricky to get rid of.
… AND THEN ANOTHER COLONY
LI C E
M A N IA !
Head lice breed so quickly that they soon run
out of space on your head and have to look for
somewhere else to live. Fortunately, there are
loads of other heads around. Head lice cannot
fly, jump or swim. Even so, it takes a louse
just 30 seconds to transfer from one human
head-hotel to the next. It does this
by crawling from hair to
hair – very quickly!
To a head louse, your head is
the perfect hotel and restaurant,
all rolled into one. There’s plenty
of food. All the louse has to do
is dig down into your scalp a bit
and it can suck up loads of deliciou
s
blood. The accommodation is
cleaned regularly. True, it’s slightly
inconvenient when the water sluic
es
through. But lice are excellent at
clinging on to a nearby hair, until
things quiet down.
Gettin
guests g the
to leav
e
Poli
HOW TWO LICE BECOME
A COLONY…
There’s nothing a louse likes
more than a big family to keep
it company. The louse will lay eggs,
called nits, which revel in the
warmth of a human head! After
about a week, the heat hatches the
eggs out into tiny, pinhead-sized
lice. Within another week,
they are big enough to
lay eggs of their own.
In a month, just a couple
of head lice can get quite
a colony started!
6
Look hard and head
lice are easily big
enough to see.
H A IR
tely askin
g the lice
leave won
to
’t work –
more
drastic a
ction is n
eed
They can
be got rid ed!
of by:
• Wet com
bing with a
special com
• Using a
b.
special sha
mpoo or sp
ray.
Worrying
ly, thoug
h
, some lic
have now
e
become r
esistant
to the ch
em
shampoo icals in the
s and sp
rays!
Head lice are most common in children
between the ages of four and 12 years old.
It’s because they rub their heads together
more than anyone else!
7
N O SE S
SNOT AND
BOGEYS
Have you ever sat on
the school bus in front
of someone who’s got a
snotty cold? The danger
is terrible! You never know
when they might sneeze
and whether a delivery of
snot might hit the back of
your head as a result!
WHAT’S IN A BOGEY?
EXTRA SNOTTY!
When you hav
e a cold, the bi
ts of your
nose that prod
uce mucus ge
t red and
inflamed. They
go into overdr
ive, to
try and protec
t themselves
w
it
h a nice,
thick coating
of snot. Befor
e
yo
u know
it, there’s a w
aterfall – or at
le
as
t, a
snotterfall – po
uring out of yo
ur nose.
You’d never eat a bogey if you knew what
was in them (even if you’re the kind
of disgusting person who might have
considered it before). Bogeys are made up
of mucus, plus the germs, dirt, pollen and
other harmful things that get trapped in it
before they can cause your body any harm.
By eating one, you’re just eating all the
stuff your body’s been trying to get rid of!
Don’ t c
atch
cold!
The be
st way to
avoid bein
snotty is
g
to keep fr
om
catching
a cold:
• Keep you
r nos
in cold wea e and throat warm
ther.
• Don’t ge
t too close
to peo
with colds
(no kissing ple
!): they
are infectio
us.
If you ge
ta
swift end cold, bring it to a
by drink
ing plent
of water,
y
eating we
ll and
getting p
lenty of r
est.
Of course, the human body has actually
evolved to make use of swallowed bogeys.
Our bodies are quite easily able to deal
with revolting things like bogies.
Eating a bogey won’t actually do
you any harm (unless a girl you
like sees you doing it!).
WHAT IS SNOT?
18
Snot is the slimy stuff inside
your nose. Its proper name
is mucus and its job is to
protect your lungs from
things like dust, dirt,
germs and pollen.
If you breathed these
in, they could cause a
dangerous infection
or reaction, or even
clutter up your nice
clean lungs. Instead,
they get caught up
in the hairs and
mucus inside your
nose. Then they are
shoved out either as
drippy snot or sticky
bogeys or even
swallowed (yuck)!
Na
stie
sg
of b et trapped
ead
in nose hair inst
eing
breat
hed into your lungs.
MU CU S MA NIA !
ucus not only appears in your
M
nose – but also lines your whole
digestive system!
• Your body normally produces about a litre of mucus every day!
•
19
FROM PEARLY
WHITES TO PEGS
In the days before
toothbrushes, very
few people over the age
of 30 ever gave a big smile.
Why? Because everyone
would recoil in horror!
Where pearly-white teeth
used to be, there were only
blackened stumps sticking
out of their gums.
WHERE DID ALL THE TEETH GO?
All those old pre-toothbrush grins were eaten
away by tooth decay. Bacteria – the same
kind of tiny creatures that cause bad breath
(and boils and carbuncles) – also cause tooth
decay. It happens like this:
r teeth
Bacteria on you
what’s
form a layer of
called plaque.
24
When you eat or drink,
the bacteria in plaque
also get a meal! While
eating tiny bits of food,
they create acid.
show,
It just goes to
lways
you should a
u teeth!
look after yo
ke
ay at teeth li
Acid eats aw
d
being poure
warm water
e
lso affects th
on to ice. It a
unchecked
gums. If left
ill rot away
your teeth w
n have
and may eve
d.
to be remove
TEETH
BEATING BACK
THE BACTERIA
The reason most of us don’t
have rotten stumps for teeth,
like people in the past,
is that we brush our teeth
with fluoride toothpaste.
This scrubs away most of
the bacteria. The few that
are left take several hours to
rebuild their forces, ready for
another plaque attack. In the
meantime, the teeth are safe.
y
a
c
e
d
p
Kee
y
at beca
is
ay at bay
MYTH BUSTER!
Through the ag
es there have be
en some crazy
myths about to
oth decay. Here
are just three:
Myth 1: Tooth de
cay is caused by
worms.
This idea starte
d because the ho
les of early toot
decay look a bit
h
like woodworm
. It’s not true, th
ough!
Myth 2: The mor
e you brush, th
e stronger
your teeth.
Actually, brushi
ng your teeth to
o much wears aw
the tooth’s hard
ay
outer layer and
makes rotten te
more likely!
eth
Myth 3: Having
a tooth removed
affects
your eyesight.
A common myt
h that is definite
ly NOT true!
Brushing for three
minutes, twice a da
y,
keeps tooth decay at
bay.
tooth d
e the
Keeping
. Here ar to
le
t
t
a
b
t
n
fight
a consta
do in the
o
t
s
g
in
key th
r teeth:
keep you
sugar,
ally LOVE
e
r
ia
r
e
t
c
rink.
a
• Plaque b s of sugary food or d
t
so avoid lo
at
meals – th
n
e
e
w
t
e
b
at
• Do not e arve the bacteria
t
u
way, yo s
sion.
is
into subm
g
the mornin
in
h
t
e
e
t
r
u
• Brush yo you go to bed for at
fo
e
e,
and b re
s each tim
e
t
u
in
m
e
e
ger.
least thr
doesn’t lin
ia
r
e
t
c
a
b
t
so tha
25
MEET LA
PÉTOMANE
S
T
R
A
F
D
N
A
D
N
WI
What is wind? Where does
it come from? And why
does it often try to escape
from your bottom at the
worst possible moment? If
you want to know what
farts are, how they’re made,
why they smell and how
you can avoid having
mighty wind – read on.
GUTS
e
La Pétomane was th
s flatulist
world’s most famou
r.
or professional farte
air
He was able to suck
,
m
tto
in through his bo
wanted.
t again whenever he
then fart it back ou
tness
uld pay money to wi
Amazingly, people wo
Pétomane
1880s and 1914 La
e
th
n
ee
tw
be
d
an
this
ded
eatres. His act inclu
toured the world’s th
s away, and
from several metre
les
nd
ca
t
ou
ng
wi
blo
ument)
ocarina (a wind instr
playing tunes on an
m by a rubber pipe.
connected to his bu
TOP TRUMPER!
On average, males fart
14–25 times a day and
females 7–12 times a day.
Some people fart as many
as 40 times a day!
WHAT CAUSES FARTING?
Farting happens when gases build up inside your
digestive system. There are only two ways they can
be released – farting or burping. But where do the
gases come from?
They are released by your body as you digest your
food or they come from air you have swallowed,
down into your gut, instead of breathed in. This
happens during eating, especially if you gulp food
down instead of chewing it. Chewing gum, sucking
on pen tops and smoking also lead to people
swallowing a higher-than-usual amount of air.
ARE SOME FOODS MORE FARTY THAN OTHERS?
Some foods contain material that is difficult to
digest. This partly-digested food passes through
your body, but before being expelled it is broken
down by bacteria. One of the side-effects is a lot
of extra gas, which has to be farted out. Particularly
farty foods include beans, cabbage, artichokes,
lentils, prunes, apples and Brussels sprouts.
28
Oh no!
WHY DO FARTS
Sometimes you just
can’t keep it in!
SMELL BAD?
Actually, most farts don’t
smell bad – so no one notices
them. The stinkers that people
do notice happen when your
food is not properly digested.
The food begins to rot inside
you and starts to release
sulphur gas. It’s the sulphur
that stinks.
29
GUTS
WHAT HAPPENS WHEN YOU VOMIT?
VOMITING
Vomiting usually
happens when your
body decides it
doesn’t like what’s
in your stomach and
throws it out. Often,
you don’t have much
choice about it, apart
from having to decide
very quickly where
to park a delivery of
hot, fresh sick.
•
VOMIT
MANIA!
hales v
W
omit eve
ry week o
as a norm
r so,
al way of
getting ri
of things
d
they can
’t digest!
Owls do
a similar
thing.
• Whe
n cats gro
om them
they ofte
selves
n swallow
some fur.
This fur is
hard to d
igest, so
get rid o
to
f it cats v
omit it o
ut!
30
WHY DO PEOPLE
VOMIT?
selves
hs empty them
ac
om
st
’s
le
p
Peo
The
rent reasons.
for lots of diffe
’ve
is because they
on
m
m
co
t
os
m
they
by something
been poisoned
ence
runk. As a def
d
or
n
te
ea
e
hav
es to
eir body decid
mechanism, th
omach.
ything in its st
er
ev
of
d
ri
t
ge
ickly!
appens very qu
This usually h
use
ple vomit beca
eo
p
es
im
et
om
S
t
or worried abou
they are scared
ake
m
few people even
A
g.
in
h
et
m
so
hoping
it deliberately,
om
v
es
lv
se
them
ulimia
This is called b
to lose weight.
gerous.
and is very dan
When your body decides to vomit, things happen
very quickly and without any help from you:
in triggers
Firstly, the bra
tra saliva
a release of ex
r teeth from
to protect you
stomach acid.
Next, your body takes a deep
breath, so that it doesn’t breathe
sick into your airways. The
contents of your small intestine
(where food goes after leaving
your stomach) is sucked back up
into your stomach.
VOMITING YOUR TEETH AWAY?
Our stomachs contain a lot of
acid, which is used to digest food.
Whenever you vomit, some of this
acid comes up and coats your teeth.
If this happens once in a while,
the teeth can recover. But people
who vomit regularly end up rotting
their teeth away. They often
end up with false teeth.
The muscles in your belly squeeze tightly, forcing the
partly-digested food in your stomach to come shooting
back up into the open air at alarming speed. And if you’re
really unlucky, or try to keep it in, some will come out
of your nose as well!
31