Physiology of Finfish and Shellfish (2+1)

3.2.1. Structure of various muscles

In higher animals such as vertebrates, most movements are caused by skeletal, cardiac and smooth mucles. The skeletal muscles which have visible stripes or striations when viewed with the microscope usually contract rapidly and are under the voluntary control of animal. Cardiac muscle which makes up the heart, is unique in being striated but not under voluntary control. It continues pumping auto matically throughout the life. Smooth muscle, which does not have microscopic striations, usually contracts quite slowly and often undergoes rhythmic pulsations.