Final answer:
Certain smooth muscle cells have the ability to undergo hyperplasia, dividing to increase their numbers, which is a unique feature distinct from skeletal muscle that typically grows through hypertrophy after initial development.
Step-by-step explanation:
The true statement about smooth muscle is that certain smooth muscle cells can actually divide to increase their numbers. Smooth muscle differs from skeletal muscle in several ways. These cells are spindle-shaped, containing a single nucleus, and have the unique ability to undergo hyperplasia, where they can mitotically divide producing new cells. This contrasts with skeletal muscle, which generally does not divide after initial development but can grow through hypertrophy — the enlargement of existing muscle fibers.
Furthermore, smooth muscle is not striated, it has a network of intermediate filaments which are used for contraction, and it contains dense bodies instead of z-discs to anchor the thin filaments. Unlike skeletal muscle, smooth muscle does not have well-developed T-tubules because the cells are small enough for calcium ions to diffuse through them without those structures. Contractions can be stimulated by hormones, the autonomic nervous system, or just spontaneously, and they can be sustained for long periods due to latch-bridges. Finally, while all muscle types can experience hypertrophy, smooth muscle can also synthesize certain connective tissue (CT) elements, but this is not their primary function.