Vestibular System

Question 1

The membranous labyrinth of the vestibular system is continuous with which duct of the membranous labyrinth of the auditory system?

Answer 1

Cochlear Duct
(Scala Media)

Question 2

What are the three main purposes of the vestibular system (think about the reflexes)

Answer 2

Sense movement
Maintain posture
Stabilize images

Question 3

Name the structure that connects the auditory membranous labyrinth to the vestibular membranous labyrinth

Answer 3

Ductus Reuniens

Question 4

Within the vestibular system, the membranous labyrinth is filled with ______ and is suspended in ______

Answer 4

Endolymph
Perilymph

Question 5

Name three structures that are housed in the vestibule

Answer 5

Saccule
Utricle
Oval Window

Question 6

The sensory organ associated with the otoliths is the _______.

Answer 6

Macula

Question 7

The sensory organ associated with the semicircular canals is the _______.

Answer 7

Crista

Question 8

What are the 3 co-planar pairs of the semicircular canals?

Answer 8

RALP
LARP
Horiztonal

Question 9

The crus commune unites which of the following two vestibular structures?

Answer 9

Ampullae and Semi-Circular Canals

Question 10

Briefly describe the role otoconia play in the response of otoliths to linear acceleration/deceleration

Answer 10

When otoconia are displaced with enough force they drag the otolithic membrane across kinocilia and stereocilia, leading to shearing action

Question 11

Type I vestibular hair cells are __-shaped and innervated via a ______.

Answer 11

Flask
Nerve calyx

Question 12

Type II vestibular hair cells are __-shaped and innervated via a ______.

Answer 12

Collumnar
Terminal Bouton

Question 13

Vestibular hair cells have more ______ fibers compared to inner and outer hair cells

Answer 13

Efferent

Question 14

________ is a uniquely vestibular hair cell feature and not present in cochlear hair cells.

Answer 14

Kinocillium

Question 15

The utricle is oriented _____ and detects _____ while the saccule is oriented _____ and detects _____.

Answer 15

Horizontally
Vertical translations of the head (going up in an elevator)
Vertically
Forward/backward acceleration

Question 16

The semi-circular canals are oriented _____, _____, and _____. They function in co-planar pairs which is when one ______ another _____ .

Answer 16

Posteriorly
Anteriorly
Horizontally
SCC responds in an excitatory fashion
SCC responds in an inhibitory fashion

Question 17

The superior portion of the vestibular nerve innervates the ______, ______, and ______.

Answer 17

Horizontal SCC
Anterior SCC
Utricle

Question 18

The inferior portion of the vestibular nerve innervates the ______ and ______.

Answer 18

Saccule
Posterior SCC

Question 19

Displacement of the stereocilia in the direction of the kinocilium results in a(n) _______ response

Answer 19

Excitiatory

Question 20

Describes the physiology of the cristae, in response to movement

Answer 20

There are cristae in the ampulla of each semicircular canal. Cilia embedded in gelatinous membrane (cupula) of the cristae respond to angular acceleration and deceleration

Question 21

If the head turns right, an excitatory reaction is triggered in the _______ SCC and an inhibitory reaction in the ______ SCC

Answer 21

Right Horizontal
Left Horizontal

Question 22

If the head shifts down, an excitatory reaction is triggered in the _______ SCC and an inhibitory reaction in the ______ SCC

Answer 22

Left Anterior and Right Anterior
Left Posterior and Right Posterior

Question 23

Name the 3 vestibular reflexes

Answer 23

Vestibulo-ocular reflex
Vestibulocollic reflex
Vestibulospinal reflex

Question 24

The vestibulo-ocular reflex….

Answer 24

Allows for stabilization of gaze with head movement

Question 25

The vestibulocollic reflex...

Answer 25

Maintains balance and awareness of body in space

Question 26

The vestibulospinal reflex...

Answer 26

Connects the vestibular end organs to the spinal cord and mediates posture

Question 27

State the VOR pathway when the head turns LEFT

Answer 27

Endolymph in both horizontal SCCs moves right In the right SCC, kinocilium are bent away from utricle In the left SCC, kinocilium are bent towards utricle Increased firing rate from left horizontal SCC

Question 28

Name the six pathways from the vestibular nuclei in the central vestibular system

Answer 28

Nausea Balance and Cerebellum Eye movements / image stabilization Conscious awareness of the sensations Neck + head movement Arm + leg posture

Question 29

The two major components of the eye movements in the VOR are the _______ and _______

Answer 29

Saccidic System Smooth Pursuit

Question 30

______ is the objective measurement of vertigo

Answer 30

Nystagmus

Question 31

Label the vestibular system

Answer 31

Question 32

Label the ducts

Answer 32

Question 33

Label the vestibular nerve

Answer 33

Question 34

Label the cross-section of an SCC

Answer 34