BMS 870 Lecture Notes - Lecture 19: Dorsal Root Ganglion, Motor Unit, Neuromuscular Junction
24 Dec 2017
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Motor system - all muscles, and neurons that control muscles. Brain - control motor programs in spinal cord. Voluntary control of body movements via skeletal muscles. Functions to move bones around joints, move eyes in head, to inhale and exhale, control facial expression, produce speech. Enclosed by connective tissue sheath - forms tendons at ends of muscle. Within each muscle, hundreds of muscle fibers (cells of skeletal muscle), each of which are innervated by a single cns axon branch. Where humerus (upper arm none) bound by fibrous ligaments to radius and ulna (bones of lower arm). Flexion - closing movement caused by muscles that cause flexion, flexors (brachiallis, brachii, coracobracialis). Flexors and extensors pull in opposite directions = antagonists. Muscles only pull on elbow joint, never push. Axial muscles - muscles responsible for trunk movement. Somatic musculature is innervated by somatic motor neurons in ventral horn of spinal cord, which are lower motor neurons.
