01:377:213 Lecture Notes - Lecture 3: Skeletal Muscle, Sarcomere, Myosin
20 Dec 2019
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Document Summary
Pumping blood in the heart, veins and arteries. Muscles connect from one bone to another to create movement. Can create movement at one part of the body or the whole body. Excitability - muscles respond to a stimulus to contract. Contractility - muscles create force or tension. Extensibility - can contract over various lengths. Help enter and exit food throughout the body. Sarcomere - where the action takes place. Caused by interactions between thick and thin filaments within the sarcomere. Triggered by the presence of calcium ions. When a muscle contracts, actin filaments slide toward each other. Cross-bridge binding - myosin heads bind to actin. Motor unit - all muscle cells are controlled by a single motor neuron. Muscle tone - the tension of a muscle at rest. Muscles spindles - specialized cells monitored by sensory nerves to control muscles tone. Muscle atrophy - discontinued use of a muscle. Weakness, decrease size in the muscle, muscle starts breaking down.
