auditory function and balance

Question 1

diagram of ear

Answer 1

Question 2

diagram of external ear canal, middle ear, cochlea and labyrinth

Answer 2

Question 3

diagram of anatomy of labyrinth

Answer 3

Question 4

superior projection of right bony labyrinth on base of skull: diagram and angles of canals

Answer 4

as stimulus is movement, important to have correct orientation; anterior canal 45 degrees forward, posterior canal 45 degrees back, lateral canal 30 degrees (in between)

Question 5

2 components of outer ear

Answer 5

pinna (auricle) and external acoustic meatus (external auditory meatus/auditory canal)

Question 6

function of outer ear

Answer 6

collects and conduct sound waves towards tympanic membrane

Question 7

location of middle ear

Answer 7

air-filled chamber in bone, lying between tympanic membrane laterally and oval and round windows medially

Question 8

2 components of inner ear

Answer 8

cochlea and organs of balance; inner ear in petrous part of temporal bone (well protected); ampulla on one end of canal, not on other end

Question 9

function of inner ear

Answer 9

hair cells transduce mechanical energy of sound into electrical signal in cochlear nerve

Question 10

diagram of auditory pathway

Answer 10

Question 11

diagram of middle ear

Answer 11

Question 12

anatomical features of cochlear

Answer 12

hollow tube in bone, curled into spiral; divided longitudinally into 3 compartments, separated by 2 membranes; cochlear hair cells attached to basillar membrane

Question 13

2 membranes of cochlear which vibrate with sound waves

Answer 13

vestibular (Reissner’s) and basillar membranes

Question 14

diagram of cochlea

Answer 14

Question 15

anatomical features of organ of corti

Answer 15

hair cells surrounded by support cells; tectorial membrane; spiral ganglion embedded in modiolus; stria vascularis secretes endolymph (high in K+ and low in Na+)

Question 16

feature of tectorial membrane

Answer 16

gelatinous so doesn’t vibrate with sound

Question 17

what does spiral ganglion innervate

Answer 17

hair cells

Question 18

diagram of organ of corti (spiral organ)

Answer 18

Question 19

how many otolith organs in each ear, and what are the two components

Answer 19

5 otolith organs (saccule and utricle)

Question 20

what is the saccule connected to

Answer 20

cochlear

Question 21

what is the utricle connected to

Answer 21

saccule

Question 22

what connect to utricle

Answer 22

semicircular canals (anterior, posterior, lateral)

Question 23

why is there fluid in vesitbular part of labyrinth as well as auditory part

Answer 23

help move hair cells to make transduction due to movement of head