Lecture 14: Vestibular and Auditory Systems Flashcards
Which part of the ear contains petrous portion of temporal bone, bony labyrinth, and membranous labyrinth?
A. Outer Ear
B. Inner Ear
C. Middle Ear
B. Inner Ear
True or False: The Membranous Labyrinth contains perilymph
False - the bony labyrinth does!
True or False: The Inner Ear serves both hearing and equilibrium
True
Membranous labyrinth consists of ____ and ____ ___
Vestibule
A. Saccule
B. Urticle
Semicircular canals
What is the function of the vestibule (saccule + urticle)?
A. Detects motion
B. Detects linear acceleration
B. Detects linear acceleration
True or False: The saccule has the macula in its FLOOR while the utricle has the macula in its LATERAL WALLS
True
Which of the following parts of the vestibule detects up and down movement of the head, as well as forward and backward?
A. Saccule
B. Utricle
A. Saccule
Which of the following parts of the vestibule detects side to side movements of the head (linear acceleration in lateral plane)?
A. Saccule
B. Utricle
B. Utricle
Detection of hair cells during head movements causes firing of ____
Action Potentials
Which two structures are embedded in the otolithic membrane?
- Crystals
- Hair cells
True or False: When head moves, this leads to crystals of the ear moving, which leads to matrix movement, hair cell deflection, then nerves firing
True
True or False: The Vestibule is responsible for detecting angular acceleration and head rotation
False - the Semicircular ducts do this!
How many ducts are located in the body semicircular canals?
Three
____ is the dilated end of the semicircular duct
A. Kinocilla
B. Ampulla
C. Cillia
D. Endolympth
E. Crista Ampullaris
B. Ampulla
Within the semicircular ducts, there is the ampulla (dilated end of duct). Within the ampulla, there is ____, which is the sensory end organ containing hair cells
A. Kinocilia
B. Crista Ampullaris
B. Crista Ampullaris
How are the stereocilia of the ampulla arranged?
A. graduated rows
B. graduated columns
C. no specific arrangement
A. graduated rows
Which of the following is the LONGEST true cilium found in the ampulla of the semicircular ducts?
A. Kinocilium
B. Crista Ampullaris
C. Cupula
A. Kinocilium
True or False: Kinocilia of the hair cells in any given crista are oriented in DIFFERENT directions
False - kinocilia of hair cells in any given crista are oriented in the SAME direction
True or False: Kinocilia of hair cells in the horizontal ducts are oriented VERTICALLY
false - toward midline
True or False: There are three semicircular ducts (anterior, posterior, and horizontal) -
Each is positioned at right angles to each other and work in pairs
True
True or False: When one moves their head, endolymph move in the same direction
False - moves in opposite direction
When one moves their head, it deflects the kinocilium toward midline, leading to AP firing of ___ fibers
afferent
What decreases firing rate of AP’s?
A. Deflection of kinocilium towards midline
B. Kinocilium moving away from midline
B. Kinocilium moving away from midline
Movement of ____ causes deflection of kinocilia and neuron firing
endolymph
Sensory nerves are located in vestibular
ganglion, also known as ____ _____
Scarpa’s Ganglion
Ganglion cells are bipolar. Where does the peripheral process synapse?
Receptor hair cells
True or False: The vestibulocochlear nerve attaches to the brainstem at the potomedullary juntion in the pontocerebellar angle
True
The central axonal process of the ganglion cell will project ipsilaterally to which two structures?
- Vestibulocerebellum (maintains equilibrium and coordinates eye movements with head, neck, and body)
- Vestibular Nuclei
True or False: There are 4 vestibular nuclei - superior, inferior, medial, and lateral
True
Vestibular afferents terminate in
ipsilateral ____ ____
vestibular nuclei
The Lateral Vestibular Nucleus gives rise to Lateral Vestibulospinal Tract (LVST).
What does it innervate?
What is its function?
Innervates: extensor musculature
Function: maintains balances/allows for postural changes
The Medial Vestibular Nucleus gives rise to the Medial Vestibulospinal Tract.
What does it innervate?
What is its function?
Innervates: neck musculature
Function: stabilizes head
Which of the vestibular nucleus give rise to cerebellar afferents that project to the vestibulocerebellum?
A. Medial vestibular nucleus
B. Lateral vestibular nucleus
C. Superior vestibular nucleus
D. Inferior vestibular nucleus
C. Superior vestibular nucleus
D. Inferior vestibular nucleus
True or False: The vestibular nuclei also project to contralateral paramedian pontine reticular formation
True