Auditory 2 Flashcards
What are the 3 systems required for proper balance? (functioning of motor activities, eye movements, & posture)
- Vestibular System
- Visual System (least reliable)
- Prioreceptive
-no vestibular = nausea &vomiting ( position of head & body in space)
What is within the bony labyrinth? Membranous labyrinth?
- Perilymph (bony)
2. Endolymph(membranous)
What are the 2 otolyphic organs?
- Utricle (horizontal)
2. Saccule (vertical movement)
Where is the vestibular system located in the skull?
in the petrous part of the TEMPORAL bone
- lateral to the internal acoustic meatus (along w/ cochlea)
The bony & membranous labyrinths of vestibular system are continuous with the Auditory system: TRUE OR FALSE
- what fluids are in each?
TRUE
- Bony = PERILYMPH
- Membranous = ENDOLYMPH
What are the 3 main divisions of the vestibular system? Which two are otolithic organs? What movement do each serve?
- Semicircular canals (circular motion)
- Utricle - horizontal
- Saccule - verticle
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?
- ENDOLYMPH
2. Hair cells
What organ of the vestibular system uses the MLF to coordinate movements of the eye w/ head & neck?
SEMICIRCULAR canals
- use CN 3,4,6
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?
- AMPULLA of the canal (ampulary crest & cupola)
2. CUPOLA
If the head moves to the right, which direction does the cupola move? What is this called?
- Cupola moves LEFT (opposite)
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?
- DEPOLARIZATIOn (K+ in)
- HYPERPOLARIZATION
- K+ influx
- depolarization
- calcium released
- NT released
- Bipolar cells FIRE AP
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
- clockwise (TOWARD KINOCILIUM)
= increase FIRING!!!
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?
- Posterior canal on left
- Anterior canal on left
HORIZONTAL CANALS ARE PAIRED
If there is an infection, or if one canal in a specific plane stops working, this is perceived as____
MOVEMENT
- increase in K+
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