Australian_Science_Illustrated_Issue_52_2017

74 | SCIENCE ILLUSTRATED

Ear stones

and hair keep

your balance

A

good sense of balance is not located in your
body, but in your ear. The vestibular sense
makes sure that you can remain on your feet
without getting dizzy, every time you move your
head. The sense is regulated by a sophisticated
system of hair, crystals, etc. in the internal ear.
When you look to both sides before crossing
the street, a liquid moves in the internal ear,
bending small, ultra-sensitive hairs, which are
linked with the acoustic nerve. The nerve sends
signals to the brain, which compares the
information to sensory impressions from the eyes
and neck, etc., to estimate whether it is only your
head which is moving, or whether you have lost
your sense of balance and are about to fall.

3 The acoustic nerve registers the

motions of the sensory

hairs, sending the

information to the brain,

where it is processed.

2 2 small sacs belowthe semicircular canals

include ear stones – microscopic

calcium crystals, which are shaken

to activate sensory hairs, as you

move your head up and down.

1 The semicircular canals are 3

canals filled with

liquid. When your head

moves, the liquid

moves, activating small

sensory hairs which

function as sensors.

Ear and brain are directly linked

A complex system of canals and nerve links in the ear ensures

that your brain always knows where your head is.

SENSORY HAIRS

COCHLEA

SHUTTERSTOCK & SPL

2 SENSE OF BALANCE

Your sense of balance is controlled

by small sensory hairs in the ears,

which detect motion, sending

a message to the brain.

Your internal ear is covered in

3,500 microscopic hairs that detect

even your slightest of motions.

HUMANS SENSES