KINESIOL 1A03 Lecture Notes - Lecture 10: Intercostal Muscle, Skeletal Muscle, Myocyte
29 Oct 2018
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Document Summary
Properties of skeletal muscle: contractility: ability of a muscle to contract forcefully. The contractile proteins inside muscle give muscle this ability: excitability: capacity of a muscle to respond to a stimulus by producing action potentials. Action potentials are on the plasma membrane of the muscle voltage gated ion channels (plasma membrane in skeletal muscle has voltage gated channels). Only way to send an action potential to muscle is to stimulate a neuron: extensibility: muscle can be stretched beyond its resting length and still be able to contract. E. g. if you stretch or hyperextend your arm, you can still contract the muscles: elasticity: the ability of the muscle to recoil to original resting length after its been stretched. The elasticity is aided by elastic proteins in the muscle fiber however, the proteins cannot go against a huge amount of force. Skeletal muscles can only contract they cannot be stimulated to relax. But only one: fibers are long, cylindrical, multinucleated.
