Body location–skeletal muscle is attached to bones or to skin (some facial muscles); cardiac muscle is located in the walls of the heart; smooth muscle is found in the walls of hollow visceral organs (other than the heart).
Microscopic anatomy–skeletal muscle consists of very long, cylindrical, multinucleated cells with very obvious striations; cardiac muscle consists of branching chains of cells that are uninucleated and possess striations; smooth muscle consists of single fusiform uninucleated cells that lack striations.
Regulation of contraction–skeletal muscle is voluntary via nervous system controls, but this normal voluntary control can be overridden by involuntary reflex arcs (as explained in later chapters); cardiac muscle is involuntary via the heart pacemaker, nervous system controls, and hormones; smooth muscle is involuntary via nervous system controls, hormones, other chemicals, and stretching.
Speed of contraction–skeletal muscle is slow to fast; cardiac muscle is slow; smooth muscle is the slowest.
Rhythmicity–skeletal muscle is arrhythmic; cardiac muscle is rhythmic; smooth muscle is sometimes rhythmic.
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