Review of Medical Physiology - William F. Ganong 2002

Physiology of Nerve and Muscle Cells
Excitable Tissue: Muscle
Smooth Muscle - Multiunit Smooth Muscle

In terms of Structure, multi-unit Cytology/cytology/32.html">Smooth Muscle tissue, unlike visceral smooth muscle, is not a syncytium, and the contraction of individual elements within it does not propagate. As a result, contractions of multi-unit smooth Muscles are more discrete and precise than those of visceral smooth muscles. Like visceral smooth muscles, multi-unit ones are highly sensitive to various chemical substances present in the bloodstream and are activated by chemical Transmitters (acetylcholine and noradrenaline) released at their motor nerve terminals. In particular, noradrenaline has The ability to sustain prolonged Muscle contraction following a transient stimulus. Consequently, the contractile response of multi-unit smooth muscles resembles unwarped tetanus rather than a single twitch. The single twitch of a multi-unit muscle is similar to that of a Skeletal Muscle, except that in the case of the multi-unit muscle, the duration of contraction is ten times longer.



Last update: 10/08/2026

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