Vestibular System Flashcards
The vestibular system ____ us in space and tells us whether or not we are ____.
Orients
Moving
The vestibular system, like the auditory system, is connected to the _____ nerve, or ____ ____ ____.
Vestibulocochlear nerve
Cranial nerve VIII
How many semicircular canals does the vestibular system have? What are they called, and what is the difference between them?
3: superior, posterior, horizontal
Each is in a different orientation
What does the ampullae contain and what is it attached to? In regards to the ampullae, what is the function of the semicircular canals?
Hair cells of semicircular canals, attached to semicircular canals
Semicircular canals provides greater space for endolymph to circulate in order to cause bending of hair cells in ampullae
What are the names of the 2 otolith organs of the vestibular system?
Saccule
Utricle
Yaw rotation corresponds to what type of movement and mostly activates what semicircular canal?
Spinning around
Horizontal
Pitch rotation corresponds to what type of movement and mostly activates what semicircular canal?
Tilting head front or back
Superior canal
Roll rotation corresponds to what type of movement and mostly activates what semicircular canal?
Tilting head left or right
Posterior canal
In the ampulla, the hair cells are in the (same/different) orientation as one another.
Same
In the otolith organs, the ____ divides them down the center. On either side of the division, the hair cells are oriented in the (same/opposite) directions as those across the division.
Striola
Opposite
Because the hair cells of the otolith organs are oriented in opposite directions across the striola, some hair cells are ____ with a particular type of movement while others are ____.
Excited
Inhibited
How is hair cell orientation of the utricle different from the saccule with regards to the striola?
Utricle: long stereocilia are oriented towards striola
Saccule: long stereocilia are oriented away from striola
All hair cells on one side of the striola will have the same orientation of ____ to _____.
Longest
Shortest
On top of the hair cells in the otolith organs is a gelatinous _____ layer topped with _____, which are essentially ____ ____ crystals. How does this layer affect hair cell bending upon head bending?
Endolymph
Otoconia
Calcium carbonate
Layer applies weight that causes bending of all hair cells in otolith organs upon bending of head and keeps them bent for duration of head bending
Hair cells of otolith organs: head is tilted forward, hair cell is (excited/inhibited) and (returns to baseline before head is erected/ remains excited as long as head is tilted). When does the hair cell return to baseline? What happens to the hair cell when the head is tilted backwards?
Excited
Remains excited as long as head is tilted
Returns to baseline when head is no longer tilted
Hair cell is inhibited when head is tilted backwards
Hair cells of otolith organs: forward acceleration mimics turning head (forward/backward). Does deceleration activate or inhibit hair cells?
Backward
Inhibit
Each ampule has a grouping of hair cells in the (same/different) basic orientation. Are all the hair cells excited or inhibited by the same movement, or are only some?
Same
All are excited or inhibited by same movement
In the ampula, sloshing of ____ on one side causes ____ on the other side to move, bending the hair cells towards the (shortest/longest).
Endolymph
Fluid
Longest
The otolith organs sense ___ ___ and ___ acceleration.
Head tilt
Linear acceleration