BIOL-2220 Chapter Notes - Chapter 9: Neuromuscular Junction, Endoplasmic Reticulum, Skeletal Muscle
18 Oct 2016
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Document Summary
Skeletal muscle- muscle composed of cylindrical multinucleate cells with obvious striations; the muscle(s) attached to the body"s skeleton; voluntary muscle. Voluntary muscle- muscle under strict nervous control; skeletal muscle. Smooth muscle- spindle-shaped cells with one centrally located nucleus and no externally visible striations (bands). Found mainly in the walls of hollow organs. Contractility- muscle cell"s ability to move by shortening. Sarcolemma- the plasma membrane of a muscle fiber. Myofibril- rodlike bundle of contractile filaments (myofilaments) found in muscle fibers (cells) Sarcomere- the smallest contractile unit of muscle; extends from one z disc to the next. Myosin- one of the principal contractile proteins found in muscle. Sarcoplasmic reticulum (sr)- specialized endoplasmic reticulum of muscle cells. T tubule (transverse tubule)- extension of the muscle cell plasma membrane (sarcolemma) that protrudes deeply into the muscle cell. Contraction- to shorten or develop tension, an ability highly developed in muscle cells.
