• provides info on the position of the head at any given moment
• do this by responding to movement of fluid in temporal bone - acceleration of endolymph

• made of:  Semicircular Canals + cochlea

• made of: semicircular ducts + cristae ampullares

• occurs when body is moving but head is still
• ex. when in car and light turns green

1. Cupula - for semicircular ducts + cristae ampullaris

2. Otolithic membrane - for Utricular + saculuae

• eyes are moving but rest of body is still
• ex. reading book
• ex. sitting on right side of a moving train

• body moving but gaze is fixed on target
• medial longitudinal fasciculus is dealing iwth CN 3,4,6 so you remain looking at object
• ex. spin in circle but eyes on one point

• testing system to see how well it is working
• COWS
• ex. cold water in r ear = nystagmus L....bc body thinks temporal bone is moving L so eyes reset L