Inside the Living Body Page #2

Our immune system is under develop

and we can't fight infections of our cells

amazingly our mother fights them for us

through her milk

The close contact between mother and baby

means she absorbs the same germs they're attacking us

her Mature immune system creates antibodies to kill off these bacteria

Then, in masterpiece of natural design

she passes those antibodies to her baby in breast milk.

until our own immune system develops, she will keep us safe

Breast feeding builds a deep bond between mother and child

a bond that will guide us through infancy,and into the outside world

At this age, even a simple trip to the supermarket

is a sensory overload

It's noisy , bright and smelly

High up inside the nose, the specialised olfactory nerves

???? in the stream of air we breathe

they detect chemicals and send an electrical signal to the brain

Our brain interprets these signals as smells

Our sense of smell is very sensitive

we quickly learn to recognize smells

and can identify our mother with our nose

The strange new world is also very noisy

We're bombarded with hundreds of strange new sounds

sound waves make the eardrum vibrate

On the other side of the eardrum

these tiny bones, the ossicles vibrate in sympathy

They're the smallest three bones in our body

They're so small that can fit on a fingertip

???get any bigger, they stay the size all our life

But without them we would never hear a thing

the ossicles are the air amplifiers

they amplify the volume 22 times

The amplified vibrations enter the inner ear - the cochlea

it's lined with delicate hairs

When vibrations pass through, the hairs vibrate

at the top - low-frequency hairs ,

at the base - fragile hairs to high frequency sounds

Each one 200 times thinner than a hair on our head

Over time, loud noises will damage these hairs

but at this age, they are perfect

our hearing will never be this good again

for eye sight, the story is different

The world is blurred and without color

Our eyes're around the develop

we can't pointerize where we ???

and a imature lenses can not focus

The lens flips the image it receives,

our brains corret the image later

Babies can't yet see in color

because the retina, the screen in the back of the eye,

is also immature

the retina has two types of special cells: rods and cones

They turn light into electrical signals

the ones to detect color, the cones are still developing.

so we see almostly in black and white

From the retina, the signals travel along 2 thick nerves

to the back of brain where we process visual information.

When the image arrives, the real challenge begins

Our immature brain has not yet learned to interpret the data

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