Hearing

Question 1

External ear functions

Answer 1

initial funneling of sound waves towards the middle ear

produces cerumen

Question 2

External ear sections

Answer 2

1. Pinna
2. Vertical ear canal
3. Horizontal ear canal

Question 3

Pinna

Answer 3

made up of elastic cartilage and is lined with apocrine sweat glands

Question 4

Cerumen

Answer 4

ear wax

protects the tympanic membrane from bacteria, debris, moisture, fungi, insects

can become thick, causing a blockage that could lead to infections

Question 5

Tympanic membrane

Answer 5

Ear drum

Separates the external ear from the middle ear

collects sound waves and transfers the vibrations to the malleus

Question 6

Middle ear functions

Answer 6

transfers vibrations to the inner ear, regulates pressure of the middle ear cavity

Question 7

Middle ear consists of

Answer 7

Lateral to medial

1. Malleus
2. Incus
3. Stapes

Question 8

Auditory Ossicles: Malleous

Answer 8

directly connected to the tympanic membrane, then the incus and then the stapes

transfers sound vibrations down the auditory ossicles and into the inner ear

Question 9

Auditory Ossicles: Stapes

Answer 9

Directly connected to the oval window

Question 10

Auditory Tube

Answer 10

Eustachian’s tube

regulates pressure in the middle ear if it becomes too high or too low

Question 11

Inner Ear functions

Answer 11

Amplifies and transduces sound vibration

regulates equilibrium

Question 12

Inner ear sections

Answer 12

1. Cochlea
2. Vestibule
3. Semicircular canals

Question 13

Cochlear nerve

Answer 13

the terminal structure of the inner ear

brings transduced vibrations to the brain for perception

Question 14

Cochlea

Answer 14

Responsible for sound

Sprial shape increases the length while not too big

Question 15

Sterocilia

Answer 15

lines hair cells

used to sense sound vibrations and physical contact

Question 16

Sound travels through the cochlea

Answer 16

After sound waves are transferred to the inner ear

• the stapes causes the oval window to vibrate
• which causes the perilymph to vibrate
• perilymph brings vibrations to endolymph
• vibrations are transferred to the organ of corti
• organ of corti turns vibrations into electrical signals
• transfers it to the brain

Question 17

Organ of Corti

Answer 17

-most important structure of inner ear
-lines the cochlea
-lined with hair cells with stereocilia on top
-extremely sensitive to sound vibrations
-Any vibrations picked up by the stereocilia will be transduced from a physical vibration to neural impulse
Sends it to the brain for interpretation

Question 18

Vestibule

Answer 18

• Maintains equilibrium when the head is still
• lies between the cochlea and semicircular canals
• epithelium is lined with hair cells that hold stereocilia
• surrounding the hair cells is a matrix that contains otoliths

Question 19

Otoliths

Answer 19

Ear stones

Question 20

When the head is tilted

Answer 20

• gravity will cause the otoliths to move
• otoliths will hit the stereocilia
• contact sensation is transduced into a neural signal telling the brain which way the head is tilted

Question 21

Semicircular canals

Answer 21

• maintain equilibrium when the body is moving
• absent of otoliths
• instead a gelatinous mass called the cupula surrounds the hair cells

Question 22

As the head rotates…

Answer 22

• the cupula moves in the opposite direction

- the stereocilia on the hair cells collects the information and processes it to the brain

Question 23

Otitis externa

Answer 23

inflammation of the outer ear

can cause extensive discharge and minor to moderate superficial hemorrhaging

typically causes pain and discomfort

Question 24

Otitis media

Answer 24

Inflammation of the middle ear

can lead to hearing impairments if serious

inflammation makes it harder for the auditory tube to open causing pressure-induced discomfort

Question 25

Otitis interna

Answer 25

Inflammation of the inner ear Can cause hearing impairment Cause vestibular impairment