Sensory System - Balance Flashcards
The Saccule and utricle each contain macula. The macula contains epitheal membrane that contains ______ cells and sensory ____ cells
supporting cells and sensory hair cells
The macula rests on the ______ membrane
otolithic
The otolithic membran contains crystals called ________.
otoliths
The otoliths weight on the otolithic membrane causes displacement of the _______ and ________ according to the orientation of the head.
Stereocilia and kinocilium
The force of the gravity in the stimulus acts on the sensory structire macula which transduces the stimulus into _______ impulses
neuronal
Bending of the ________ towards the kinocilium produces depolarization.
stereocilia
Tilting the head toward the kinocilia will cause depolarization of the ______ receptors
sensory
The depolarization of the sensory hair cells causes the release of neurotransmitters on the _______n fibre of the vestibulocochlear nerve, which branches off to the vestibular nuclei
vestibilar
Positional information is provided by the ______
macula
Only a fraction of the hair cells will be stimulated by a particular orientation of the head. Why
Since the orientation of the hair cells differ
There are three semicircular canals, each directed to detect movement on one of three spatial dimensions
True or False
True
The fact that someone can read on the bus while it hits bumps is because of the _____ _____ reflex. This is also known as VOR
vestibular-occular reflex
the VOR is triggered by ______ ______
crista ampullaris
How does the VOR work
a brief movement of the head will cause a brief movement of the crista ampullaris through the endolymph and cause the eyes to reflexively move to our original point of focus
With continuous motion of the head, the movement of the crista ampullaris ultimately causes the endolymph to flow at the same speed as the head and it is no longer bending the cupula. when the head stops the endolymph will continue its motion causing nystagmus
True or False
True
What is nystagmus
reflexive back and forth movement of the eyes
Fibers of the vestibular nerve join the vestibulocochlear nerve which branches off to synapse onto cells of the lateral and superior parts of the vestibular nuclei. The vestibular nuclei has some projection to the brainstem to participate in reflexes and other bilateral projections to the ventral posterior thalamus which then projects onto the vestibular cortex in the parietal lobe. What does this explain
The sensory pathway of balance
