PNB 2264 Lecture Notes - Lecture 12: Motor Planning, Motor Learning, Substantia Nigra
23 Jan 2017
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Document Summary
Balance and posture require continuous information about position and motion of all body parts, including the head and eyes. Feedback information from the head and eyes must be independent of each other, since the eyes can be fixed on a target even when the head is moving. Two kinds of equilibrium: static, head position / tilt, dynamic, linear, vertical and angular acceleration. Maculae: hair cells, otolithic membrane, otoliths. Each macula consists of groups of hair cells on inner surface of fluid (endolymph)-filled chamber (membranous labyrinth. ) The hairs are embedded in a gelatinous substance (the otolithic membrane) that contains tiny particles of calcium carbonate (otoliths). Under the influence of gravity (or acceleration/deceleration), the gelatinous substance exerts force on the hair cells. As the position of the head changes, the hairs are bent in different directions. Function: maculae of utricle: horizontal acceleration (and deceleration) and head position (tilt, maculae of saccule: vertical acceleration (and deceleration)
