Final

Question 1

where is action potential generated within the auditory system

Answer 1

cochlea - hair cells depolarize

Question 2

auditory pathway

Answer 2

cochlea, spiral ganglion, CN VIII (cochlear nerve), cochlear nucleus, axons project into the superior olivary complex, crossover/decussation, lateral lemniscus, inferior colliculus, geniculate nucleus (thalamus), auditory cortex

Question 3

BAEP Wave I

Answer 3

standing wave, distal end of the acoustic division of the VIII nerve

Question 4

BAEP Wave II

Answer 4

standing wave, proximal end of the acoustic division, brainstem entry, cochlear nucleus, trapezoid body

Question 5

BAEP Wave III

Answer 5

standing wave, superior olivary complex

Question 6

BAEP Wave IV

Answer 6

travelling wave, later lemniscus

Question 7

BAEP Wave V

Answer 7

standing wave, inferior colliculus (most robust, should have a latency under 6ms)

Question 8

interpeak latency changes

Answer 8

> 1ms, reflects pressure of the 8th nerve

Question 9

which two nerves share the interauditory canal

Answer 9

VIII & VII

Question 10

nerves in question during skull base surgery

Answer 10

5 - facial sensation rostral to IAC & 10 & 9 (dorsal)

Question 11

CN VIII

Answer 11

Cochlear
afferent fibers from cochlea to inner ear
hearing
Vestibular
afferent fibers from equilibrium receptors to inner ear
balance

Question 12

CN VII

Answer 12

facial nerve
conveys motor impulses to facial skeletal muscles
conveys motor impulses to tear, nasal & some salivary glands
conveys sensory impulses from taste buds
Bells palsy/facial paralysis if damaged

Question 13

CN V

Answer 13

trigeminal
largest CN
sensory info from face
motor of chewing muscles

Question 14

CN 9

Answer 14

Glossopharyngeal
from medulla
motor: some swallowing muscles, some salivary glands
sensory: taste 1/3 posterior of tongue, chemoreceptors and baroreceptors

Question 15

CN X

Answer 15

Vagus nerve
extends beyond neck
motor: efferents to heart, lung, & abdomen organs
sensory: input from abdominal & thoracic viscera, taste in pharynx

Question 16

IAC phase

Answer 16

compression of VII & VIII nerve

Question 17

Cisternal phase

Answer 17

blocks blood from brainstem

Question 18

Brainstem compression phase

Answer 18

4th ventricle compression

Question 19

surgery approaches

Answer 19

translabyrinthine
middle fossa
retrosigmoid

Question 20

translabyrinthine

Answer 20

simple, but destroys cochlear/vestibular apparatus, no hearing

Question 21

middle fossa surgery

Answer 21

for IAC tumors

Question 22

joints in spinal column

Answer 22

pedicle & facet joint

Question 23

spinal stenosis & location

Answer 23

narrowing of spinal column common in lumbar

Question 24

purpose of laminectomy

Answer 24

free up space, ease stenosis

Question 25

endovascualr vs. clipping technique

Answer 25

endovascular - less invasive, coil through veins not opening of skull
clipping - risky, invasive

Question 26

SSEP measures

Answer 26

Upper: C4L & C3R, median & ulnar nerve, N20
Lower: Cz, P37, postibial nerve

Question 27

SSEP journey

Answer 27

first order neuron: dorsal root ganglion
second: dorsal column nuclei
Decussation at medulla
third: thalamus
to primary SS cortex

Question 28

MMEP recorded

Answer 28

stim from skull, record from muscle movement

Question 29

MMEP journey

Answer 29

motor cortex
decussation
lateral corticospinal tract
lower motor neuron