Physiology of Finfish and Shellfish (2+1)

3.2.8. Smooth muscle or non striated muscle

The term smooth muscle derives from the uniform appearance of the cytoplasm of stained sections when examined under the low magnification of a light microscope. Although, many cellular structures can be seen in the electron microscope but they are not nearly as striking as the internal organization of skeletal muscle cells.

Many organs of vertebrates contain smooth muscles; the stomach, intestines, bile ducts, bladder and urinary tracts, uterus and blood vessels. Smooth muscle exhibit much variation and is often separated into visceral and multi unit.

Visceral muscle operates as a syncytium and many of men also have pace maker, or self-stimulating activity. A multi unit smooth muscle is a group of cells, each of which is subjected to nervous control and can act individually in same manner as individual fibres in a skeletal muscle.