Week 1.4 - Physiology of Balance Flashcards
What is the labyrinth?
- cochlea
- 3 semicircular canals
- vestibule
What is the vestibule responsible for?
contains 2 otolith organs - uticle and saccula - and responsible for responding to gravitational forces
What are the semicircular canals responsible for?
- tells brain info about movement within space
What do the otolith organs contain?
- utricle and saccule
- each contain a macula
- macula have basal membrane, hair cell, uneven stereocilia with longest kinocilium, which move when endolymph fluid (gel) moves
- contain otoliths - calcium carbonate stones - which add momentum to movement of cilia.
What do the 3 semicircular canals respond to?
- superior responds to nodding
- posterior responds to tilting toward shoulder
- lateral responds to no movement
What is the main difference between the vestibule and the cochlea?
vestibule has base firing rate and the way we move determines the speed of the firing rate.
Where does the vestibular nerve pick up signals from and where do these signals travel?
from the macula of otolith organs and the ampulla of the semicircular canals, through the external auditory meatus to pair with the cochlear nerve, to form the vestibulocochlear nerve, and then the facial nerve
What do the semicircular canals contain?
- 3 canals 90° to each other
- all connected to the utricle.
- have 1 ampulla each - sensory organ
What is the structure of the ampulla and role?
semicircle canal full of endolymph. has cupula membrane, which is displaced by water movement. causes kinocilia on cristae to move which results in nerve activity via vestibular nerve
What is the vestibulo-ocular reflex?
reflex which stabilises gaze, set up by kinocilia and ampula. allows our eyes to stay in 1 place while we move our head.
What does an issue with our vestibulo-ocular reflex cause?
dizziness and vestibular problems
