14 Vestibular System

Question 1

inner ear consists of two main sections which are

Answer 1

inner membranous labyrinth

outer bony labyrinth

Question 2

bony labyrinth consists of three areas:

Answer 2

semicircular canals

vestibule

cochlea

Question 3

These contain the receptors for equilibrium

Answer 3

semicircular canals and the vestibule

Question 4

This system maintains stable eye and body position in response to changes in head positioning.

Answer 4

vestibular system

Question 5

Within the vestibule are the parts of the membranous labyrinth which are

Answer 5

utricle

saccule

Question 6

-is the sensory receptor area of the utricle and saccule

-has receptor hair cells that are embedded in an otolithic membrane consisting of a gelatinous material covered by a glycoprotein studded with calcium carbonate crystals called otoliths (otoconia), which are relatively heavy

Answer 6

macula

Question 7

The utricle receptors lie in a ____ plane, and those of the saccule lie in a ____ plane

Answer 7

horizontal

vertical

Question 8

what are the three semicircular canals

Answer 8

anterior

lateral

posterior

Question 9

what is the swollen area at the end of each canal

Answer 9

ampulla

Question 10

Inside the semicircular canals are the parts of the membranous labyrinth called

Answer 10

semicircular ducts.

Question 11

Each of the three ampullae in the semicircular canal contains
sensory receptors called the

Answer 11

crista

Question 12

Sensory receptor cells in cristae ampullaris are hair-like structures called ____ comprising a kinocilium and numerous stereocilia.

Answer 12

sensory hair cells

Question 13

Each stereocilium is connected to its neighbor called a

Answer 13

tip link

Question 14

Arising from the crista and completely encapsulating the stereocilia is a gelatinous structure called the

Answer 14

cupula

Question 15

two types of equilibrium:

Answer 15

static and dynamic

Question 16

refers to the maintenance of the position of the body while not moving

Answer 16

Static equilibrium

Question 17

is the maintenance of body position in response to sudden movements such as acceleration, deceleration, and rotation

Answer 17

dynamic equilibrium

Question 18

structures that are mostly involved in static equilibrium but are also involved in dynamic equilibrium by responding to linear acceleration.

Answer 18

Macula within the utricle and saccule

Question 19

Movements of the stereocilia toward the kinocilium cause the sensory hair cell membrane to ____ while movements away from the kinocilium cause ____

Answer 19

depolarize

hyperpolarization

Question 20

The 1st order vestibular afferents arise in

Answer 20

Scarpa’s ganglion or vestibular ganglion

Question 21

what are the four 2nd-order vestibular nuclei:

Answer 21

inferior vestibular nuclei

medial vestibular nuclei

lateral (Deiter’s) vestibular nuclei

superior vestibular nuclei

Question 22

The main descending tracts

Answer 22

lateral vestibulospinal tract (from the lateral vestibular nucleus)

medial vestibulospinal tract (from the medial vestibular nucleus)

Question 23

main ascending tracts?

Answer 23

superior and medial vestibular nuclei to the extraocular muscles through the medial longitudinal fasciculus (MLF)