myofibril

myofibril

[mahy-uh-fahy-bruhl, -fib-ruhl]
noun Cell Biology.
a contractile fibril of skeletal muscle, composed mainly of actin and myosin.

Origin:
1895–1900; myo- + fibril

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Medical Dictionary

myofibril my·o·fi·bril (mī'ə-fī'brəl, -fĭb'rəl)
n.
One of the threadlike longitudinal fibrils occurring in a skeletal or cardiac muscle fiber. Also called sarcostyle.

The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
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Encyclopedia Britannica
Encyclopedia

myofibril

very fine contractile fibres, groups of which extend in parallel columns along the length of striated muscle fibres. The myofibrils are made up of thick and thin myofilaments, which help give the muscle its striped appearance. The thick filaments are composed of myosin, and the thin filaments are predominantly actin, along with two other muscle proteins, tropomyosin and troponin. Muscular contraction is caused by the interaction between actin and myosin as they temporarily bind to each other and are released.

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Encyclopedia Britannica, 2008. Encyclopedia Britannica Online.
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