08.1 Mechanisms of Hearing

Question 1

What determines the pitch of a sound?

Answer 1

Frequency of the soundwave (Measured in Hz)

Question 2

What is volume measured in?

Answer 2

Decibels (Db)

Question 3

What is the cochlear’s structure?

Answer 3

Like a shanil shell

canal has 2 sections, scala vestibule and the scala tympani

Question 4

Where do vibrations travel from the middle ear?

Answer 4

Enter the oval window
Into the scala vestibule
Out of the round window

Question 5

What is the organ of corti?

Answer 5

Sensory area that contains hair cells

Question 6

What do the inner and outer cells of the organ of corti do?

Answer 6

Inner cells - sense sound

Outer cells - detect amplitude of sound

Question 7

What happens after the stereocilia of hair cells are exposed to sound?

Answer 7

Displace laterally
Influx of potassium ions into the hair cell
Depolarisation
Calcium influx
Neurotransmitter release
CNVIII fires

Question 8

What is the central auditory pathway?

Answer 8

CNVIII
Acoustic meatus
Posterior cranial fossa
Divides into vestibular and cochlear branches at the brainstem
Cochlear nuclei in medulaa
Medial geniculate nucleus
Auditory cortex

Question 9

What can cause conductive hearing loss?

Answer 9

Osteosclerosis
Otitis media
Rupture tympanic membrane
Blocked external acoustic meatus

Question 10

What can cause sensorineural hearing loss?

Answer 10

Damage to the cochlear
Damage to CNVIII
Central auditory pathway damage
Damage to hair cells via ototoxic drugs