CGSC379 Lecture Notes - Lecture 4: Semicircular Canals, Otolithic Membrane, Kinocilium

• School: University of Delaware
• Department: Cognitive Science
• Course: CGSC379
• Professor: Kathleen Riley

Document Summary

Longest hair cell at top of cell. Tubular with decreasing stiffness from bottom to top. Bundle of hair cells (similar to hearing mechanism) Gelatinous membrane in semicircular canals - at the base (bottom of arch) Movement of stereocilia causes change in potential (left ear goes one way while right ear goes the other direction) Visual system is tied to vestibular system: Eyes move opposite head turn, or stay steady. Quick return of the eyes to direction of head turn. Results from an abnormal neural connection between vestibular and visual systems. Slow movement in one direction, fast return in opposite direction. Electrodes placed around the eyes, measure eye movements while turning head. Information about posture, movement and body in space. Cranial nerve testing - stick tongue out and move it r/l. Determine peripheral (coming from one of ears) vs. central etiology (more central to brain) Saccade, smooth pursuit, optokinetic and gaze fixation. Patient asked to perform visual tasks while recording.