Membrane Potentials and Action Potentials in Smooth Muscle Membrane Potentials in Smooth Muscle.
The quantitative voltage of the membrane potential
of smooth muscle depends on the momentary condition of the muscle. In the normal resting state, the
intracellular potential is usually about −50 to −60 millivolts, which is about 30 millivolts less negative
than in skeletal muscle.
Figure 8-5 A, Typical smooth muscle action potential (spike potential) elicited by an
external stimulus. B, Repetitive spike potentials, elicited by slow rhythmical electrical waves
thatoccur spontaneously in the smooth muscle of the intestinal
wall. C, Action potential with a plateau, recorded from a smooth mus le fiber of the
uterus. Unit II Membrane Physiology, Nerve, and Muscle 96
