Parts of Nervous System. Nervous System: Nervous system is the chief controlling and coordinating system of the body. It controls and regulates all activities of the body, whether voluntary or involuntary, and adjusts the individual (organism) to the given surroundings.
Compared to skeletal muscle, smooth-muscle cells are small. They are spindle-shaped, about 50 to 200 microns long and only 2 to 10 microns in diameter. They have no striations or sarcomeres. Instead, they have bundles of thin and thick filaments (as opposed to well-developed bands) that correspond to myofibrils.
1. Skeletal muscle: refers to most muscles that are under voluntary control. These are cylindrical and often pretty long (because they are multinucleated), with the nucleus on the edge of the muscle so as to not interfere with contractions. 2.Cardiac muscle: refers to the muscles of the heart (cardiomyocytes).here skeletal muscle is voluntary, cardiac muscle is autorhythmic (beats involuntarily; generates its own action potentials). 3. Smooth muscle: refers to the muscles that are controlled involuntarily by the brain, like those attached to the base of hair follicles or in the walls of the gastro-intestinal tract.