What are the 3 systems required for proper balance? (functioning of motor activities, eye movements, & posture)
-no vestibular = nausea &vomiting ( position of head & body in space)
What is within the bony labyrinth? Membranous labyrinth?
2. Endolymph(membranous)
What are the 2 otolyphic organs?
2. Saccule (vertical movement)
Where is the vestibular system located in the skull?
in the petrous part of the TEMPORAL bone
The bony & membranous labyrinths of vestibular system are continuous with the Auditory system: TRUE OR FALSE
TRUE
What are the 3 main divisions of the vestibular system? Which two are otolithic organs? What movement do each serve?
UTRICLE & SACCULE are otolithic organs
(semicircular canals just have endolymph)
What fluid is essential for the creation of receptor potentials? What are the primary receptors in the Vesitbular (and auditory) system?
2. Hair cells
What organ of the vestibular system uses the MLF to coordinate movements of the eye w/ head & neck?
SEMICIRCULAR canals
Which vestibular organ is the primary gravity & acceleration sensor?
UTRICLE
Where are the hair cells in the semicircular canals located in? What is the gelatinous substance that covers the hair cells?
2. CUPOLA
If the head moves to the right, which direction does the cupola move? What is this called?
2. INERTIAL DISPLACEMENT of the fluid & cupola - bends hair cells
The inertial displacement is an acceleration force or a velocity?
ACCELERATION
but considered velocity
What occurs when the sterocilium move towards the kinoocilium? AWAY?
What fires action potentials, hair cells or bipolar cells?
BIPOLAR CELLS
The greater the difference in INERTIAL DISPLACEMENT = the greater _____
greater perceived “velocity”
actually acceleration, but perceived as velocity
If the head is moving counterclockwise, which direction does the fluid on the left & right move in the horizontal canals?
LEFT: moves OPPOSITE
RIGHT: moves counterclockwise
- AWAY from kinocilium = decrease in firing
The anterior canal on right is paired with ____ canal on left.
The posterior canal on right is paired with the ____ canal on the left.
Which canals are paired?
HORIZONTAL CANALS ARE PAIRED
If there is an infection, or if one canal in a specific plane stops working, this is perceived as____
MOVEMENT
What has a tonic output in the vestibular system? As long as this cancels out on both sides, the brain perceives it as NO MOVEMENT
vestibular Nerve
so that the decrease or increase in K+ can be sensed by the vestibular system
Because the saccule & utricle contain OTOLITHIC granules (calcium carbonate), this allows them to respond to what?
GRAVITY
Where are the auditory hair cells located?
Organ of Corti on a thin basilar membrane in the COCHLEA of the inner ear
Which organ (SSC, utricle or saccule):
UTRICLE!!!
Which organ (SSC, utricle or saccule):
SACCULE
Describe the pathway of INPUT TO CNS from the hair cell to the vestibular nuclei: