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.
Types of smooth muscles-. Single unit(most of the smooth muscles are of this type) Multi-unit eg-Ciliary muscles. 8.Both types of muscles contain actin and myosin filaments,but in Skeletal muscles,Actin:Mysoin=2:1,while for smooth muscles,Actin:Mysoin=10:1. Actin and Myosin are muscle filaments which contract or relax,causing the whole muscle to perform the desired action.