Note: Muscles are of two kinds, striated and nonstriated. The
striated muscles, which, in most of the higher animals,
constitute the principal part of the flesh, exclusive
of the fat, are mostly under the control of the will,
or voluntary, and are made up of great numbers of
elongated fibres bound together into bundles and
inclosed in a sheath of connective tissue, the
perimysium. Each fiber is inclosed in a delicate
membrane (the sarcolemma), is made up of alternate
segments of lighter and darker material which give it a
transversely striated appearance, and contains,
scattered through its substance, protoplasmic nuclei,
the so-called muscle corpuscles. The nonstriated
muscles are involuntary. They constitute a large part
of the walls of the alimentary canal, blood vessels,
uterus, and bladder, and are found also in the iris,
skin, etc. They are made up of greatly elongated cells,
usually grouped in bundles or sheets.
2. Muscular strength or development; as, to show one's muscle
by lifting a heavy weight. [Colloq.]
3. [AS. muscle, L. musculus a muscle, mussel. See above.]
(Zo["o]l.) See {Mussel}.
{Muscle curve} (Physiol.), contraction curve of a muscle; a
myogram; the curve inscribed, upon a prepared surface, by
means of a myograph when acted upon by a contracting
muscle. The character of the curve represents the extent
of the contraction.