Test 2 - Lecture 8 (Vestibular System)

Question 1

saccule and utricle report

Answer 1

static head position relative to the gravitational axis AND movements that cause linear acceleration and deceleration

Question 2

hair cells are arranged into an approximately elliptical patch

Answer 2

the macula

Question 3

stereocilia extend into a gelatinous sheet

Answer 3

the otolithic membrane

Question 4

5 sensory organs in the internal ear

Answer 4

1 and 2 - utricle and saccule (otolith organs)
3 - horizontal semicircular canals
4 - anterior semicircular canals
5 - posterior semicircular canals

Question 5

the tall edge of the stereocilia are oriented either towards or away from a central line

Answer 5

the striola

Question 6

saccule

Answer 6

vertical plane: vertical linear acceleration (head up and down)

Question 7

utricle

Answer 7

horizontal plane: horizontal linear acceleration (left and right roll)
- primary gravity center

Question 8

______ movement of the head cause the endolymph to displace the cupula in the opposite direction, relative to the ____ of the head

Answer 8

rotation

Question 9

each semicircular canal extends from the utricle to the

Answer 9

ampulla

Question 10

thickened zone of epithelium (contain hair cells)

Answer 10

ampullary crista

Question 11

at the ampulla the lumen of the canal is traversed by a gelatinous diaphragm, the

Answer 11

the cupula

Question 12

three coplanar pairs in semicircular canal

Answer 12

• two horizontal canals
• anterior canal on the RIGHT and posterior canal on the LEFT
• posterior canal on the RIGHT and anterior canal on the LEFT

Question 13

side head is turning to _______, head turning away from ______

Answer 13

depolarization, hyperpolarization

Question 14

clockwise flow of the endolymph will displace the cupula causing

Answer 14

increased firing on the LEFT, decreased firing on the RIGHT

Question 15

medial and superior nuclei

Answer 15

semicircular canals (afferent input)

• vestibulo-ocular reflexes
• coordination of eye and neck muscles

Question 16

lateral nuclei

Answer 16

otolith organs (reports changes in head position)

Question 17

inferior (descending) nuclei

Answer 17

otolith organs (primarily) 
- coordination of balance and voluntary movements

Question 18

leftward head rotation evokes _____ eye movement

Answer 18

rightward