KINE 3020 Study Guide - Midterm Guide: Intrafusal Muscle Fiber, Alpha Motor Neuron, Extrafusal Muscle Fiber

• School: York University
• Department: Kinesiology & Health Science
• Course: KINE 3020
• Professor: Merv Mosher

Document Summary

Topic 3 sensory-motor systems 1: control of muscle. For our muscles to move we have input from spinal interneurons, sensory input from muscles spindles, input from upper motor neurons in the brain (sensory info), and alpha motor neurons for sending info on muscle actions. The alpha motor neuron (lower motor neuron) =cell body in the ventral door in spine. The input for a muscle follows a chain of info. When you are falling your local circuitry helps you realize when to put your muscles on stretch and contract. A motor unit is a motor neuron and all muscle fibres that it innervates (cell body, axon , presynaptic terminals that land on multiple muscle fibres) Motor unit is the bodies smallest unit, motor unit size depends on function. Explosive power depends on the recruitment of many motor units. Ocular motor units for example produce small fine movements so not as many motor units are recruited (they are also smaller in size)