Physiology of Balance Flashcards
What controls balance?
labryinth of the inner ear
What are the outputs from the balance system?
vestibulo-ocular: eye movement related to posture
vestibulo-spinal: anti gravity muscles in the lower limbs, controls gait
What is special about the utricle and saccule?
they have stereocilia projecting upwards that helps the brain percieve movement
How are movements percieved by the stereocilia?
changes in the resting firing rate
What causes stereocilia to deflect and therefore percieve changes of direction etc?
cupula sits in the ampulla of the semicircular canal
the movement of perilymph causes it to deflect which causes the stereocilia to also deflect
What happens to the vestibulocochlear reflex when there is a problem in one ear?
No signals go to the brain from the problem ear, meaning that there will be no signals telling the eye to move
What is a spontaneous nystagmus?
flickering eye away fro the damaged ear side
graded by alexanders law
What is Oscillopsia?
no vestibular input so the eye goes all shaky
What does gentamicin do to the vestibulocochlear nerve?
toxic to the nerve - makes you lose vestibular function
