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.
Smooth Muscles vs Cardiac Muscles. The two most confusing muscle types are the cardiac muscle and smooth muscle. The reason for such confusionmay be because of both being characterized with involuntary contractions unlike the long and powerful skeletal muscles (somatic muscles) that can contract voluntarily.