Chapter 9: (Module 11-The Vestibular System)

Question 1

Vestibular system

Answer 1

a complex system that together with the cochlea occupies the bony labyrinth of the temporal bone. It consists of:

the vestibule
(utricle and Saccule)
three semicircular canals,

Question 2

Vestibule

Answer 2

main function is to inform the brain about the direction of the force of gravity in reference to the position of the head.

the part of the bony labyrinth that contains the utricle and saccule

Question 3

semicircular canals

Answer 3

main function is to inform the brain about angular changes in body velocity.

Question 4

utricle

Answer 4

one of the two parts of the vestibule; contains a sense organ called a macula that responds to linear acceleration and head position relative to gravity

Question 5

Saccule

Answer 5

one of the two parts of the vestibule; contains a sense oran called a macula that response to linear acceleration and head position relative to gravity

Question 6

macula

Answer 6

the vestibular sense organ located within the utricle the saccule that responds to:

linear acceleration of the body
body position relative to gravity.

give us the sense of accretion because of inertia

Question 7

somatosensory

Answer 7

relating to or denoting a sensation (such as pressure, pain, or warmth) which can occur anywhere in the body, in contrast to one localized at a sense organ (such as sight, balance, or taste)

Question 8

balance

Answer 8

human ability to maintain balance depends on the ability of the central nervous system t coordinate sensory input from three systems:

Vestibular
visual
somatosensory

Question 9

ear is sensitive to these main forces

Answer 9

linear accelerations
gravity
angular motion

Question 10

vestibulocochlear nerve

Answer 10

VIII cranial nerve which conveys sensory information about hearing and balance to the central auditory nervous system.

Question 11

otolithic membrane

Answer 11

a gelatinous membrane containing otoconia; the stereo cilia of the hair cells of the maculae project into the otolithic membrane and are sheared when the otolithic membrane is pulled toward gravity or moved relative to the walls of the vestibule due to inertia.

Question 12

otoconia

(“ear rocks”)

Answer 12

tiny calcium carbonate crystals located within the otolithic membrane of the maculae in the utricle and saccule.

Question 13

kinocilium

Answer 13

one stereocilia of hair cells that is taller than the others with a little bump on the end.

Question 14

Semicircular canals

(3)

Answer 14

Anterior (superior)
posterior (inferior)
horizontal (lateral)

share a common cruise

anterior canal is at a 90 angle to the posterior canal

anterior and posterior canals are at a 90 angle to the horizon

horizontal canal is at a 30 off the horizontal plane

Question 15

canthus

Answer 15

corner of the eye

Question 16

semicircular canals relationship

Answer 16

Parallel
right posterior—left anterior
left posterior—–right anterior

Perpendicular
within the same canal

(rotating your head will activate one side as if deactivates or decreases the firing rage on the other side.

Question 17

ampulla (bulge)

Answer 17

located to the end of each canal. contains a sense organ called the crista ampullaris.

Question 18

crista ampullaris

Answer 18

sense organ of balance located within each of the three ampulla of the semicircular canals; responds to angular acceleration. Contains hair cells that project into a gelatinous mass called a cupula

provides information about angular acceleration

Question 19

cupula

Answer 19

a gelatinous mass that is part of the crest ampullaris; the stereociia from the hair cells of the crest ampullaris project into the cupola and are sheared by the inertial lag of the cup;a in relationship to the motion of the semicircular canal wall.

Question 20

vestibular ganglion

(Scurpa’s ganglion)

Answer 20

the collection of cell bodies of the afferent vestibular nerve; locate in the internal auditory canal.

Picture of the nerve on pg 2 of power point.
2 parts with nerves going to different parts of the ear`

Question 21

Vestibular-ocular reflex

(VOR)

Answer 21

a reflex that allows the eyes to stay focused on an object even when the body is moving; due to a connection between the vestibular system and the oculomotor system, which controls eyeball movement.

Question 22

vertiginous

Answer 22

sit in a chair and spin

make people have vertigo

Question 23

Nystagmus

(trigger vert by laying someone flat and irrigation their ear with cold or warm air or water)

Answer 23

a vision condition in which the eyes make repetitive, uncontrolled movements. These movements often result in reduced vision and depth perception and can affect balance and coordination. These involuntary eye movements can occur from side to side, up and down, or in a circular pattern.

Question 24

Elecrtonystagmography

ENG

Answer 24

measures electrical potential changes as the eye moves