Kinesiology 3341A/B Lecture Notes - Lecture 13: Alpha Motor Neuron, Muscle Contraction, Central Tendon Of Diaphragm

• School: Western University
• Department: Kinesiology
• Course: Kinesiology 3341A/B
• Professor: Jim Dickey

Document Summary

Tendons and ligaments can"t shorten muscles attempt to shorten, lengthen, and stay the same length. The relative amount of activation of the muscle and the amount of load applied determines whether or not the muscle can shorten. Muscles have tendons in order to store and recover energy (humans do not do this very well because our tendons are very short and strong) Actin= thin, crossbridges formed when myosin head attaches to the actin. An electrical impulse ows down the nerve from the motor cortex to the alpha motor neuron and out towards individual muscle bres. Motor unit: motor neuron + muscle bres innervated by that motor neuron motor neurons innervate many bres and the electrical impulse is dispersed among the muscle. *when muscles fatigue, the body needs to respond by recruiting more motor units in order to maintain the same force. Fatigue can happen at multiple points (ie. calcium, atp, build up of lactic acid)