Single-unit smooth muscle, or
visceral smooth muscle is a type of
smooth muscle found in the
uterus,
gastro-intestinal tract, and the
bladder. In SUVSM, a single smooth muscle cell in a bundle is innervated by an
autonomic nerve fiber. An
action potential can be propagated through neighbouring muscle cells due to the presence of many
gap junctions between the cells. Due to this property, SUVSM bundles form a syncytium that contracts in a coordinated fashion (such as uterine muscles do during childbirth).