Smooth muscle cells are spindle-shaped, with a single, centrally located nucleus. Unlike skeletal and cardiac muscle cells, they lack striations due to the irregular arrangement of actin and myosin filaments. Smooth muscle cells are found in the walls of various hollow organs, such as blood vessels, the gastrointestinal tract, and the bladder. Their contraction is involuntary, controlled by the autonomic nervous system and various hormonal signals. Histologically, smooth muscle cells are identified by their elongated shape and the absence of striations.
