Physiology 1021 Lecture Notes - Lecture 2: Primary Motor Cortex, Reflex Arc, Receptive Field

• School: Western University
• Department: Physiology
• Course: Physiology 1021
• Professor: Angela Nissen

Document Summary

1 motor neuron and all of the muscle fibers that are controlled by that motor neuron. What makes up a motor nerve: many motor neurons. The specific motor neuron that is connected to it. Many motor units of different fiber types. In the gray matter of the spinal cord. One somatic motor neuron and all of the skeletal muscle fibers that it innervates. What are alpha motor neurons: cell bodies found in the ventral horn throughout the spinal cord that innervates skeletal muscles, always excitatory, must inhibit the alpha motor neuron to inhibit the muscle. Innervates the extrafusal muscle fiber to initiate a contraction response. Gamma motor neuron that comes from the cns to innervate the intrafusal fibres by contracting. Tonically afferent sensory neurons that send the muscle spindle stretch activation information to the cns. The pull the slack to cause the muscle to contract in the muscle spindle.