Vestibular System Flashcards
What are the two otolith organs? What are their roles?
Utricle, saccule: detect linear acceleration of head and head tilt
What do the semicircular canals do?
Sensitive to head rotation
Angular acceleration of head
What do vestibular hair cells do?
They transduce physical motion into neural signals
How does the transduction process work?
Movement of Stereocilia toward kinocillium opens voltage gated potassium channels
What do otolith organs detect?
Static displacements and linear accelerations
What are the two elements of the otolithic membrane?
Gelatinous layer covered by otoconia
During linear accelerations, what happens between sensory epithelium and otolithic membrane?
“Shearing” motion. The greater mass of the otolithic membrane, causes it to temporal tilt lag behind sensory epithelium, leading to transient displacement of the hair cell bundle.
This is TRANSIENT!!
Ex: when car accelerates
What happens during static tilt?
Hair cell response is sustained, not transient.
In which plane is the utricule mainly concerned in for motion?
Horizontal
In which plane is the saccule mainly concerned in for motion?
Vertical
What expansion is at the base of each semicircular canal?
Bulbous expansion called the ampulla
What is in the ampulla?
The sensory epithelium called the crista that contains hair cells
Can endolymph flow through the cupola?
No
What happens when the head turns in the plane of the semi circular Canals?
The inertia of the endolymph creates a force across the cupula, moving it away from the direction of head movement and causing displacement of hair bundles
Slide 21!!! Work on it
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