Final answer:
Unitary smooth muscle has electrically coupled fibers through gap junctions that synchronize contractions, allowing the muscle to operate as a singular functional entity in various body organs.
Step-by-step explanation:
Unitary smooth muscle:
Unitary smooth muscle, also known as single-unit smooth muscle, has electrically coupled fibers that synchronize contractions across the muscle tissue. This process is facilitated by gap junctions connecting the muscle fibers, allowing for coordinated muscle contractions. In contrast to multiunit smooth muscle, which lacks these connections and does not coordinate contractions, unitary smooth muscle operates as a single functional entity, responding wholesomely to stimuli—which can be induced by the autonomic nervous system, hormones, spontaneous depolarizations, or by stretching.
This type of muscle is found in the walls of various organs, including the gastrointestinal tract and bladder, aiding in peristalsis and accommodating gradual filling and emptying. The presence of gap junctions in unitary smooth muscle ensures that depolarization and the subsequent contractions spread throughout the tissue, acting collectively rather than as individual muscle cells.