Vestibular Pathway Flashcards
What are the 2 labrynths of the vestibular pathway and what are they filled w
Static labrynth and kinetic labrynth filled with endolymph
What does the static labrynth consist of and receptors
Utricle and sacule
-Maculae in wall of saccule and floor of utricle
What does the kinetic labrynth consist of and receptors
3 semicircular ducts and the 3 cristae ampullaris
What are the receptors of the static labrynth and what do they detect
Maculae utricle (on floor)- detects horizontal acceleration
Maculae sacule (on wall)- detects vert acceleraton
How is the sensory cells of the maculae set up (hair cells)
Sensory hair cels with steriocilia and 1 kinocilium with tips embedded in otolithic membrane
-basal poles connected to dendrites of vestibular nerve
What is the sensory receptor of kinetic labrynth and what does it detect
crista ampularis (x3)- sense for rotation
Sensory component setup of crista ampularis
Same arrangement of steriocilia and 1 kinocilum
- Tips embedded in cupula (no othlic this time)
- basal portion is connected to vestibular n
What is the 1st order neuron of the vestibular pathway and where is it located
Vestibular ganglion of scrap (located in int acoustic meatus)
How do axons from 1st order neuron enter brainstem
enters thru lat most part of the pontomedullary groove
What is the 2nd order neuron of the vestibular pathway
Vestibular nuclei
What are the 4 locations the vestibular path can travel after the 2nd order neuron
- Thalmus(VPM) and eventually to cerebral cortex
- Down to spinal cord (vestibule-spinal tract)
- MN 3,4,6 thru mlf for vestbibulocochlear reflex
- cerebellum via vestibulocerebellum
What is the 3rd ofer neuron of the vestibular path
VPM
Where does the vestibular path project to in brain
Project to vestibular area/intraparietal sulcus
What can Vertigo be caused by
BBPV, meniers disease, labrynthitis, vestibular neuritis
How is BBPV caused
Crystals from otoliths disloge and fall into semicircular canals and interfere with maculae and cristea ampularis
