Vestibular System (3)

Question 1

what are the stimuli that activate the vestibular system

Answer 1

gravity and tilt = otolith organs (utricle and saccule)

head rotation = semicircular canals

Question 2

what is the function of the vestibular sacs

Answer 2

detect GRAVITY and TILT
otoliths move gelatinous cap which moves hair cells which polarizes/depolarizes the cell which decreases/increases rate of action potentials

Question 3

what is the function of the semicircular canals

Answer 3

detect ROTATIONAL ACCELERATION

responds to the endolymph movement of the cupula

Question 4

how do the utricle and saccule detect head orientation/gravity and linear acceleration

Answer 4

they are sensitive to the otoliths’ mass that changes due to gravity

Question 5

how do the semicircular canals detect head rotation

Answer 5

they detect the movement of the cupula in the endolymph

Question 6

what is the vestibular ocular reflex

Answer 6

the VOR feels the motion of the body and produces an exact opposite movement of the eyes

Question 7

what cranial nerve sends vestibular information to the brain

Answer 7

cranial nerve VIII

Question 8

describe the vestibular pathway!!

Answer 8

1. the otoliths and hair cells move due to gravity (similar to auditory system)
2. can go different places in the brain
   cerebellum=balance, VP nucleus of the thalamus, extraocular motor neurons, limb motor neurons, neck motor neurons