NRSC 277 Chapter Notes - Chapter 13: Alpha Motor Neuron, Dorsal Root Ganglion, Myocyte
Document Summary
Bulk of muscle mass of body; movement; facial expression, speech, etc. Each muscle is enclosed in a connective tissue sheath that forms the tendons. Muscle fibers - each fiber is innervated by a single axon branch from cns. Lines digestive tract; plays role in peristalsis, control of bp and blood flow. Movement in the direction that closes a knife - flexion. Movement in the direction that opens a knife - extension. Flexors - work together at a join; synergists -> muscles all work together. Muscles that pull in opposite directions of each other - antagonists. Proximal or girdle muscles - shoulder, elbow, knee, pelvis. Distal muscles - hand, feet and digits. Alpha motor neurons - trigger the generation of force by muscles. One alpha motor neuron and all muscle fibers it innervates collectively make up the elementary component of motor control. Motor neuron pool - collection of alpha motor neurons that innervate a single muscle.
