Vestibular System

Question 1

what is the vestibular system?

Answer 1

mediates our sense of balance

stimulus for the system is acceleration (aka gravity)

Question 2

two main parts of the vestibular system

Answer 2

1. semicircualar ducts

2. otolith organs

Question 3

semicircular ducts

Answer 3

3 mutually perpendicular ducts that detect angular acceleration
-can sense when the head turns and in what direction

Question 4

otolith organs

Answer 4

2 parts
utricle and saccule
detects linear accleration
can tell when moving and how the head is orientated with respect to earths gravity

Question 5

the vestibular system + the cochlea make up the

Answer 5

membranous labyrinth

Question 6

the entire membranous labyrinth sits inside a

Answer 6

bony cavity in the temporal bone - floating in perilymph

Question 7

transduciton is mediated by

Answer 7

hair cells

Question 8

Net functions of the vestibular system are:

Answer 8

• keep body balanced
• coordinate head and body movement
• keep eyes fixed on point in space while head itself is moving

Question 9

Disruptions in the vestibular system cause

Answer 9

nausea, vomiting, problems with movement of body, head and eyes

Question 10

when hair cells bend TOWARD kinocilium

Answer 10

• depolarize the hair cell
• increase the release of neurotransmitters
• increase the firing of afferent axon that synapses with hair cell

Question 11

when hair cells bend AWAY from kinocilium

Answer 11

• hyperpolarize the cell
• decrease neurotransmitter release
• decrease afferent axon firing

Question 12

hair cells contain mechanically-gated ion channels that

Answer 12

open or close in response to deformation of cell’s membrane because they are attached to the membrane by the cytoskeleton