Vestibulo ocular reflex
- Created by: Hannah Jeffery
- Created on: 17-04-16 13:30
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- Vestibulo Ocular reflex
- Function
- to hold the retinal image steady during breif rotation
- if not vision would be fuzzy
- very accurate 1:1 gain
- works with head velocity of 1-5KHz
- to hold the retinal image steady during breif rotation
- Ocular muscles
- six muscles that control the movement of the eye
- Muscles arranged in pairs
- oriented in similar planes as semicircular canals
- results in synchonised movements with head
- eg head movement to the right
- contraction of left lateral rectus and relaxation of right lateral rectus
- Otolith organs of vestibular system
- two types
- saccule
- vertical forces
- utricle
- horizontal forces
- saccule
- both contain
- Macula
- hair cells covered in gelatinous mass
- contains sensory epithelium
- hair cells and supporting cells
- Otoconia
- stones made of calcium carbonate that respond to forces
- make the otolithic membrane considerably heavier
- allowing recognition of head movements
- Macula
- function
- detect forces that come from
- linear acceleration
- static tilt of the head
- static tilt due to gravity
- detect forces that come from
- damage will lead to impaired body stabalisation
- two types
- Neural Innervation
- Vestibular portion of eighth cranial nerve has two devisions
- both innervate semi-circular canals, utricle and saccule
- blood supply
- complex arterial system to cochlea and vestibular system
- some parts of vestibular system receive their own supply
- explain vestibular damage without hearing loss
- Function
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