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Unit 19: Biology Part 2 Page 75 of 137

of liquid. When the body moves in
one direction, the liquid in the
Figure 60 – Many parts of the semicircular canals also moves.
ear work together to make This causes the hairs inside to
hearing possible. move, which sends a message to
your brain, which gives instructions
From the oval window, the for the body’s muscles to contract
vibrations go to the cochlea, or relax. This keeps you balanced.
liquid-filled space lined with hairs.
The vibrations make waves in the
cochlea’s liquid, just like waves in a
pond, causing the hairs to move.
The movement of the hairs sends a

nerve impulse through the auditory
nerve to the brain. The brain
interprets the message and “tells”
you what you have heard.

Along with hearing, the ears play a Figure 61 – The semicircular
major role in balance. Inside the canals help with balance
ears are semicircular canals
which are lined with hairs and full

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