1st Project Ni Tin-tin

8/3/2019 1st Project Ni Tin-tin

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Outer ear

These are the bits we can see, and also the ear canal. They act like a funnel to catch sound waves and direct them to

the ear drum. (A canal is a pathway for water, but the ear canal is a pathway for sound)

Middle ear

This is a small air-filled space on the inside of the eardrum. There are 3 tiny bones called ossicles in this part.

They are called the hammer, anvil and stirrup (because that is what they look like). When the sound waves move the

eardrum, these bones move and pass on the vibration to the very much smaller oval shaped window of the cochlea (the

bit that looks like a shell). The hammer is touching the ear drum so it shakes when the sound comes through, and the

movement goes right through the anvil to the stirrup, which is touching the window of the cochlea.

Inner ear

The cochlea has fluid in it, which moves due to the vibrations and bends hairs on the outside of cells lining the cochlea.

There are about 17,000 hair cells in each ear, so they really are tiny. They are not like the hair on your head. Some of

these hair cells (the 'inner hair cells') create an electrical impulse (signal), which is sent along the auditory nerve to

the brain. Most of them (the 'outer' ones), however, are like tiny muscle cells, which react to the vibrations in the fluid

by trembling and shaking; in this way they work like high quality amplifiers and make the vibrations much stronger and

clearer for the smaller number of inner hair cells. The brain then works out what you are hearing.

The semi-circular canals in your inner ear contain fluid

too. They send messages to your brain to help you keep

your balance when you move.

Hearing

If your ears are working well, you

hear sounds all the time. You

can’t switch your ears off, even

when you are asleep.

Listening

When you really want to listen to something you tell your brain to concentrate on that sound. If your ears are healthy

and are both working well, they can 'turn down' other sounds while you concentrate on what you want to hear.

If one ear isn’t working as well as the other

then they can’t do this as well. If your outer

hair cells have been damaged by too much

loud noise, what you want to hear can get

mixed up and smothered by the other sounds

around.

With healthy ears you can choose what you want to listen to, but you can't choose what you hear.



Understanding

Your brain sorts out the sounds and tells you what they mean. Some people have problems understanding what they are

hearing because their ears don't work well and they don't hear all the sounds. The brain does not get enough

information to work it out, or the messages may be mixed up.

Selective hearing

Lots of mums and dads think that kids have this particular 'problem'.

They think that you select (choose) what you

are going to hear and what you definitely can't

hear! Many mums say that dads do this too! In

fact, this is something we may all do to try and

make our lives a bit easier.

Some children wrote what

they liked to hear and what

they didn't like to hear.

Dr Kim says

Sometimes your ears feel funny when you are on a plane, going through a tunnel or driving up hills.

This is because there is air inside your ear drum and air outside. The pressure outside the ear

changes when you go up high. You need to let more air into the inside of your ear or let some out tobalance the air pressure on each side of your ear drum.Try opening your mouth wide as if you are

yawning, or chewing or blowing your nose. This lets air through the eustachian tube into the inner

ear, your ears will feel like they go 'pop' and you will be able to hear normally again.

Aren't ears wonderful?

What I like to hear

My dog barking in his sleep.

A friend saying, "Can you come

and play?"

Birds singing in the morning.

"Let's go out for tea."

I like my mummy saying that she

loves me.

I like to listen to music.

"Do you want an ice-cream?"

Mum saying goodnight.

I like to hear the computer.

I like to hear tea cooking.

I like to hear dad saying, "Yes

you can stay up later."

What I don't like to hear

I don't like to hear very loud music.

I hate to hear mosquitoes buzzing in my ears.

Mum and dad arguing.

People screaming.

Chainsaws are too noisy.

Mum saying it's time for bed.

"You have to eat your vegetables."

"Tidy up your room."

People's fingernails scraping down the blackboard.



Catching soundwaves in the air.

Sending them along to where

The message gets through to your brain

Faster than the fastest train.

Sorting out what you want to hear

Whether the sound is far or near.

Wonderful music, nature's sounds

Birdsong, laughter and merry-go–rounds.

You wouldn't know when mum says, "Time for bed"

If you hadn't an ear on each side of your head.

BH



Cornea

This is the see-through skin that covers the front of your eye. It is clear like glass and it has no blood vessels

in it.

ScleraThis is the tough skin which covers the outside of the eyeball (except for the see-through cornea). We call it

the 'white' of the eye.

Iris

The iris controls the amount of light that enters the eye. The iris is the coloured part of your eye.

Pupil

This is the hole in the coloured iris. It lets light into your eye. It gets very small in bright light, and bigger in

dull light.

The lens

The lens focuses light onto the retina. It changes shape to make sure that the 'picture' on the retina is as

clear as possible.

Retina

This is like a movie screen which shows the picture you are seeing - upside down, remember? The retina has

two lots of cells called 'rods' and 'cones' (because that is what they look like.) Rods can 'see' black and white.

Cones can 'see' colours. They turn the picture into an electrical message for the brain. Sometimes people don't

see all the colours - look at our topic 'Colour blindness' to find out more.

Blind spot

This is a bit of your retina which is not sensitive to light because there are no rods or cones there. It is the

spot where the optic nerve is joined on to the retina.

Optic nerve

The electrical messages from the retina travel along the optic nerve to your brain. It's a bit like the cable

that carries all the TV pictures from your aerial to your TV so that you can see the programs. The great thing

is that our eyes take these 'movies' all the time and we don't need any film or camera.

Eyelids and Eyelashes

These protect your eyes. The eyelids

can shut out light so that you can

sleep. They will shut very fast if they

feel something that is trying to get

into your eye.

Eyelashes

Eyelashes are very sensitive, and if they feel dust coming they trap it as your eyelids close.

Eyebrows

Eyebrows also help to keep dust and sweat out of your eyes.

http://www.cyh.com/HealthTopics/HealthTopicDetailsKids.aspx?p=335&np=152&id=1700






Tear glands

These are small glands inside your upper

eye lid. Their job is to make tears to keep

the surface of your eyeball clean and

moist, and help protect your eye from

damage.

When you blink, your eyelids spread the tears over the surface of the eye. Small things that are on your eye

(like specks of dust) wash into the corner of your eye next to your nose. Sometimes tears flow over your lower

eyelid (when you cry, or you have hay fever), but mostly the tears flow down a tiny tube at the edge of your

lower eyelid, next to your nose. (If you look very carefully you can see a tiny dot that is the beginning of that

tube). This tube carries the tears to the back of your nose (and this is why your nose 'runs' when you cry!)

Conjunctiva

This is the lining on the inside of your eyelid and the outside of the front of your eye (except for the special

skin of the cornea). You can see some tiny blood vessels on the conjunctiva over your eye. If your eyes get

sore, these blood vessels get bigger and your eye looks red.

There are two lots of fluid in the eye.

Aqueous humour

Aqueous means water, and humour means fluid. This watery stuff fills the front of the eyeball around the lens.

Vitreous humour

This is a thicker jelly-like liquid which fills the larger part of the eyeball and keeps it in shape. (Vitreous means

glassy, because the vitreous humour is very clear, so that light can pass through it).

Ciliary muscles

These are a circle of tiny muscles around the lens. They change the shape of the lens by squeezing and

relaxing. They squeeze (making the lens fat) to look at nearby objects, and relax (making the lens thinner) for

far away objects. Your eyes are very beautiful and also very clever, because all the different parts work

together to help you see!

Your eyes are like a wonderful kind of camera.

They take pictures of the world around you and send the pictures to your brain. Your brain works out what

your eyes are seeing. This happens from the moment that you open your eyes in the morning to when you close

your eyes at night.

How a camera works

The light rays from an object pass through the lens of the camera and get recorded on a film or a computer

chip.

Do you notice something about this drawing? Yes, the picture that is recorded

by the camera is upside down (of course, when you look at the picture as a

printed photo or on a computer screen, it is not upside down.)



How your eyes work

Your eye works in a similar way to a camera - light passes through the lens of your eye and is 'recorded' on the

back of your eye (the retina).

Do you notice something about this drawing? Yes, the picture that your eye takes is upside down too!

Why don't you see things upside down?

Well, your eye sends the picture to your brain, and your brain turns the picture the right way up and tells you

what you are looking at. So you see things the right way up.

Dr Kate says:

Eyes are really amazing. We need to look after them very carefully, because they are so important.

Our topics on protecting your eyes and wearing glasses will help you.

Eye can see butterflies,

Eye can see clouds

Eye can see TV

Eye can see crowds.

Eye can see truth

Eye can see lies

Eye can see feelings

In other people's eyes.

BH



What to know about noses

Your nose sits in the middle of your face. If you try to look at the end of it, you go cross-eyed. The only time

you get to see it is in the mirror, and even then you can't really see it well from the side.

However you probably already know some things about noses.

We mostly breathe through our noses.

We smell things through our noses.

Our sense of smell helps us to recognise

tastes.

The two holes in your nose are called nostrils.

The end of your nose can be wiggled around

with your finger.

Some people's noses can wiggle around by

themselves!

Here are some other things you might not know:

Between the nostrils there is a wall of very thin bone and cartilage, called

the septum.

A nose bleed can occur when blood vessels in the septum break. This can be

caused by colds, dry air, exercise, pollen, bumping your nose, or picking

your nose. (If you get a lot of nose bleeds, see a doctor - especially if they

won't stop easily.)

Behind your nose is a space called the nasal cavity.

A sneeze can travel at up to 100 miles an hour – that's around 160 kms an hour!

Just think how fast and how far germs can travel from one sneeze!



Grab a tissue quickly, before you spread the germs around!

How noses work

You breathe air in through your nostrils. As the air comes in it is filtered

by lots of little hairs just inside the nostrils, to remove any dust. They

are called nasal hairs.

The inside of the nose is a bit wet and slippery at all times. This is so that

the air can have moisture added to it before it goes down into your lungs.

Your nose also warms the air that you breathe in.

The slippery stuff in your nose is called mucus [say mew-kus] - actually,

lots of kids may call mucus 'snot'.

The warm moist air that you breathe in carries oxygen down into your

lungs, and is then breathed back out through the nose (or mouth), carrying

carbon dioxide that your body is getting rid of.

If you breathe in something that irritates the little

hairs, they might make you shoot it straight back out

again. We call this ……… sneezing.

(I knew that you would know that!)

At the back of the nose is a lump of tissue, called the adenoids, which is

very much like the tonsils. It helps fight any infection when germs get in.

Professional noses

For some people, the nose is very important indeed.

Some people have very sensitive

noses, and can be found doing

very unusual jobs.

There are people who are

employed to use their ‘noses' in

the winemaking and perfume

industries. Some people's noses

can recognise thousands of

different perfumes, herbs,



spices and flowers.

Other people are employed to sniff out fumes and odours around factories to see how much pollution is being

caused.

Of course, dogs have an even better sense of smell, and their noses are used in all sorts of ways to help

humans. There are rescue dogs, drug-sniffing dogs and tracking dogs. These dogs all have a very keen sense of

smell.

All these noses

have to be trained

to do their very

important jobs!

Famous noses

In the story of Pinocchio, the wooden boy had a nose which grew longer every time he told a lie. Wouldn't it be

great if that happened in real life?

Cleopatra, the famous Egyptian queen, was known for her great beauty AND her big nose!

Cyrano De Bergerac, a character in the book and film of that name, was famous for the size of his nose.

Tycho Brahe, a famous astronomer from Denmark, had

an unusual nose – the end of it was made of gold. He

lost the real end of his nose in a sword fight.

There are some famous actors and actresses who have also been known as ‘The Nose', but we are too kind to

mention their names. You shouldn't call attention to someone's appearance and embarrass them should you?

We know that it's the character of a person that's important, not how they look.



Dr Kim says

If you have a cold, try to stay away from others so that they don't catch it from you.

Cover your nose when you sneeze, so that the germs don't fly every where. If you don't have a

tissue, use your hand, but then wash your hand before you touch anything else.

It's a good idea to use tissues to blow your nose, and then put them in a bin or flush them down

the toilet. If you stick them up your sleeve or drop them anywhere, germs will spread when

other people have to pick them up."

What kids say about noses

My dad always said, "Keep your nose clean!" when I was going out.

He meant – stay out of trouble.

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1st Project Ni Tin-tin