Ear

Question 1

2 main functions of the ear?

Answer 1

Hearing : cochlea (organ of corti)

Balance: Semicircular canals (3D) and utricle/saccule (head balance)

Question 2

3 sections of the ear, and whats in each?

Answer 2

1. Outer ear (Pinna, auditory canal)
2. Middle ear (tympanic membrane, ossicles, eustachian tube)
3. Inner ear (choclea/organ of corti, semicircular canals, auditory nerve)

Question 3

Pinna

Answer 3

• outer ear flap
• collect/focus sound waves

Question 4

Auditory canal

Answer 4

• carry sound wave to tympanic memmbrane
• ear wax comes from sweat glands here

Question 5

Tympanic membrane

Answer 5

• eardrum
• pass sound wave vibration to ossicles

Question 6

Ossicles

Answer 6

• consists of 3 small bones
  Amplify/pass sound vibrations through the:

Mallus/hammer:

Incus (anvil):

Stirrup (stapes)

Question 7

Eustachian tube

Answer 7

equalizes air pressure btwn middle ear and outside environment
- why your ears pop on plane

Question 8

Cochlea/organ of corti

Answer 8

• snail shell
• filled with fluid
• the specalized hair cells vibrate when the fluid moves
• convert sound to nerve impulse

Question 9

Semicircular canals

Answer 9

• fluid filled 3 canals contains hair that bend in response
• gives sensory information to brain for balance/equilbrium
• not sound!

Question 10

auditory nerve

Answer 10

transmits sensory info to brain

Question 11

oval window vs round window

Answer 11

oval window: small above
round window: base of snail shell

Question 12

vestibule

Answer 12

• chamber found at the base of semicircular canals provides info about static equilbrium
• connected to middle ear by 2 small savs (utricle and saccule) that establish head position

Question 13

basilar membrane

Answer 13

anchors the receptor hair cells in the organ of corti

Question 14

balance

Answer 14

vestibule: head balance
semi circular canals: body balance

Question 15

How Sound travels to brain

Answer 15

1. Pinna collects sound waves to the audacity canal
2. Auditory canal to eardrum
3. Ear drum vibrates and ossicles starts vibrating
4. Ossicles increase pressure of sound waves for the inner ear. The inner ear has liquid in it. (Needs lots of pressure)
5. Inner ear..The cochlea (snail) has liquid inside it. When ossicles hit cochlea the cochlea vibrates. Cells inside cochlea turns vibrations into electrical signals.
6. When inside the cochlea it vibrates the basilar membrane (base of cochlea/prgan of court) which bends the hair cells. The bending causes depolarization of sensory neutron which sends signal to auditory nerve.