The activity of the muscle is controlled by electrical activity within a neuron that makes contact with the muscle fiber at the neuromuscular junction. A number of differences from skeletal muscle. Differences in fiber size, number and location of nuclei, size and location of T tubules and sarcomeres, presence of intercalated discs. In contrast to skeletal muscle, cardiac muscle tissue contracts on its own in the absence of neural or hormonal stimulation. The heart has a special conducting system, a network of specialised cardiac muscle cells that initiates and distributes electrical impulses.
Smooth muscle lacks sarcomeres hence there are no striations.
The thin filaments are anchored to dense bodies. The dense bodies and intermediate filaments anchor the thin filaments so that sliding between thick and thin filaments causes cell shortening and twisting. This occurs because dense bodies are not aligned in rows. Visceral smooth muscle cells are not always innervated by motor neurons. Multiunit smooth muscle cells are innervated by more than one motor neuron.