Auditory System

Question 1

face motor path

Answer 1

precentral gyrus (bilateral)
CBT
LMN in brainstem
target muscles

Question 2

CBT lesions

Answer 2

contra lower face (all other bilateral)

Question 3

cochlea pitches

Answer 3

high pitch at base (close)

low pitch at apex (far)

Question 4

sensorineural hearing loss (conduction)

Answer 4

air > bone

Question 5

conductive hearing loss (conduction)

Answer 5

bone > air

Question 6

conductive hearing loss (examples)

Answer 6

wax buildup
gluing of ossicles
otits media
otosclerosis

Question 7

sensorineural hearing loss (examples)

Answer 7

hair cells damaged
nerves damaged
(VIII)

Question 8

hearing tests

Answer 8

weber

rinne

Question 9

weber test

Answer 9

midline of skull
loss, same ear (conductive)
loss, opp ear (sensorineural)

Question 10

rhine test

Answer 10

AC > BC normal

BC > AC conductive loss

Question 11

cochlear nuc sections

Answer 11

dorsal (freq)

ventral (localization)

Question 12

hearing path

Answer 12

hair cell
cochlear nerve (spiral gang)
cochlear nucleus (ipsi)
thru trapezoid body
sup olivary nuc (bi - pons)
thru lat lemniscus (midbrain)
inferior colliculus (midbrain)
medial geniculate body (thalamus)
sup temporal gyrus (cortex)

Question 13

lesion above cochlear nuc

Answer 13

slight bilateral loss

cant localize sound

Question 14

primary auditory cortex layout

Answer 14

under temporal
low freq, from apex = ant
high freq, from base = post

Question 15

vestibular system fxns

Answer 15

minimize retinal image motion during mvmt
important for spatial orientation
important for posture/equilibrium

Question 16

semicircular duct (mvmt)

Answer 16

angular acceleration

Question 17

atricle/saccule (mvmt)

Answer 17

linear acceleration

gravity

Question 18

vestibulo ocular reflex (VOR)

normal

Answer 18

turn head
endolymph goes opp direction
eyes go opp direction

Question 19

hair cells in VOR

Answer 19

hair cells on side you turn toward: endolymph pushes along axis of hairs, increase firing of VIII
hair cells away from way you turn: endolymph pushes against axis of hairs, decrease firing of VIII

Question 20

VOR path

Answer 20

head turn to side
ipsi vestibular gang fire
ipsi vestibular nuc
contra abducens
a. contra lat rectus
b. ipsi occulomotor thru MLF, ipsi medial rectus

Question 21

nystagmus direction

Answer 21

quick phase away from lesion

Question 22

nystagmus mech

Answer 22

L lesion
R side acts stimulated –> push slowly to L
cortex corrects (put R quickly)

Question 23

lesions –> nystagmus

Answer 23

vestibular nerve or nucleus

Question 24

water in ear

Answer 24

cold (opp): cool in L, stim R, move eyes L slowly, move quickly R

warm: warm in R, stim R, move eyes L slowly, move quickly R