Ear

Question 1

Draw a diagram of the ear

Answer 1

.

Question 2

Name the three sections of the ear

Answer 2

Outer ear, Middle ear, Inner ear

Question 3

Name the parts of the ear

Answer 3

Pinna (cartilage), ear canal, eardrum, oval window (stirrup fits against this), Eustachian tube, Cochlea, Auditory nerve, semi-circular canals, hammer, anvil, stirrup, bone (skull)

Question 4

Pinna

Answer 4

outer visible ear, funnels sound into the ear canal.

Question 5

Ear canal

Answer 5

tube leading to the ear drum. It has hairs and wax glands to trap dirt and germs.

Question 6

Eardrum

Answer 6

Membrane of skin that vibrates when sound waves his it.

Question 7

Middle ear

Answer 7

Air- filled cavity containing three small bones [ossicles] and the Eustachian tube

Question 8

Ossicles

Answer 8

3 small bones [hammer, anvil and stirrup], that amplify the sound.

Question 9

Eustachian tube

Answer 9

Keeps air pressure equal on each side of the eardrum. It opens when we swallow, cough, etc.

Question 10

When does the eustachian tube open?

Answer 10

When we swallow, cough, etc.

Question 11

Inner ear

Answer 11

Contains a coiled, fluid-filled tube called the coclea and the semi-circular canals.

Question 12

Cochlea

Answer 12

Contains nerves that convert sound vibrations into electrical impulses

Question 13

Semi-circular canals

Answer 13

help us keep our balance and posture

Question 14

Draw a diagram of how we hear

Answer 14

.

Question 15

What does the pinna (ear lobe) do?

Answer 15

channels the sound (vibrations in the air) towards the eardrum, which then vibrates.

Question 16

When the eardrum vibrates what happens?

Answer 16

It vibrates the hammer, anvil and stirrup bones, which amplify the sound

Question 17

What happens when the hammer, anvil and stirrup vibrate?

Answer 17

The stirrup pushes on the oval window of the cochlea, moving the liquid inside.

Question 18

What happens when the liquid inside the ear vibrates?

Answer 18

Special hairs on 30,000 receptor cells detect the movement and send signal to the brain along the auditory nerve.

Question 19

What happens when signals are sent to the brain?

Answer 19

The brain interprets these as sounds, and we “hear”.

Question 20

semi-circular canal

Answer 20

help us keep our balance and posture

Question 21

What can deafness be caused by?

Answer 21

Deafness can be caused by long exposure to a high level of noise, drugs, or ear infections.

Question 22

What can damage to the eardrum, ossicles [bones], and cochlea be caused by?

Answer 22

Can be caused by loud sounds, produces incurable deafness.

Question 23

What are workers exposed to prolonged sounds of over 90 decibels [dB] obliged by law to do?

Answer 23

Workers exposed to prolonged sounds of over 90 decibels [dB] are obliged by law to wear ear protection

Question 24

What does any exposure to 140dB cause?

Answer 24

Immediate damage to hearing

Question 25

What is the sound level that if workers are exposed to it for long periods of time they must do something. Is this required by law?

Answer 25

90 dB, yes

Question 26

What are the semi-circular canals composed of?

Answer 26

three curved tubes, each about 15mm long and filled with fluid

Question 27

What are head movements detected by?

Answer 27

nerves inside the semi-circular canals

Question 28

How does the brain respond to head movements detected? Why?

Answer 28

By sending messages through the cerebellum, which trigger reflex actions in our muscles. This helps us keep our whole body balanced as we move.