PHGY 209 Lecture Notes - Lecture 1: White Matter, Dont, Premotor Cortex
12 Jan 2018
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Reflexive/ involuntary: dedicated areas in the brain that for instance keep you seated up in a chair because if they weren"t doing their job you would flop over. With every movement of a limb it requires 2 things. Extension: increasing the angle around the joint (agonist) (antagonist) Flexion: decreasing angle around the joint (agonist) (antagonist) You can"t inhibit a muscle you can only inhibit the motor neurons that cause the muscle to contract. Reciprocal innervation of muscles: coordinated flexor and extensor muscle activation and relaxation, limb position is maintained by a balance of flexor and extensor muscle tension. Only excitatory release acetylcholine (ach) causing the muscles to contract. Alpha: innervate skeletal (extrafusal) muscle big muscles that allow you to move. Gamma: innervate muscle spindle (intrafusal) proprioception feedback system that reports the length of a muscle and its position. Cell bodies in ventral horn of spinal cord or brain stem (cranial nerves) inside cns.
