Vestibulocochlear Nerve Flashcards
What is the 1st function of the vestibular system?
Help maintain a stable visual image while the head is moving.
Most functions of the vestibular system are performed….at a…
Automatically (reflexively)
Subconscious (subcortical) level
Functions of the vestibular system require (1)
Sensation and perception of head position
Functions of the vestibular system require (2)
Compensatory eye movement during head movement
Functions of the vestibular system require (3)
Compensatory postural adjustment during voluntary movement
What is the 2nd function of the vestibular system?
Help maintain postural stability, especially during movement of the head (opposes gravity)
What is the 3rd function of the vestibular system?
Provide information used for body awareness and spatial orientation
The vestibular system is what kind of system?
Sensory and motor
What are the 2 receptors of the vestibular system?
Maculae and cristae
What do the 2 receptors of the vestibular system detect?
Maculae detects linear motion
Cristae detects angular motion
Where are maculae located?
In the saccule and utricle
Where are cristae located?
In the semicircular canals
Vestibular functions are subserved by what?
Receptors located in the inner ear and a control center located in the brainstem
Where specifically are cristae located?
The ampullae at the base of the semicircular canals
What is the single flexible hair filament that protrudes from the surface of a receptor to detect movement in the macula and crista?
Kinocilium
What are hair cells that project from the surface of a receptor, which cause a change in discharge frequency?
Stereocilia
What are the 2 chambers of the vestibule?
Saccule and utricle
The saccule senses…
linear motion in the vertical plane
The utricle senses…
linear motion in the horizontal plane
Where is the vestibular nucleus located?
The floor of the fourth ventricle spanning the pons and medulla
How many vestibular pathways are there?
1 sensory and 3 motor
What functions do the sensory pathway serve?
Serves the function of body awareness and spatial orientation
What functions do the motor pathways serve?
Serves the function of maintaining a stable visual image while the head is moving
Serves the function of maintaining postural stability, especially during movement of the head
Where does the sensory pathway of the vestibular system get its information?
Vestibular receptors and proprioceptors
What are the vestibular receptors of the sensory pathway responsible for?
perceiving head position and head movement
What are the proprioceptors of the sensory pathway responsible for?
perceiving body position and body movement
Which motor pathways are ascending?
The medial longitudinal fasciculus
Which motor pathways are descending?
The lateral and medial vestibulospinal tract
