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.
Here, the cardiac and smooth muscles are considered as involuntary muscles, while skeletal muscles are considered as voluntary muscles. Voluntary Muscles. Voluntary muscles are the muscles that can be controlled consciously, and are made up of cylindrical fibres. Generally, these muscles are attached to bones of the skeleton, thus called the skeletal muscles. Skeletal muscles are striated and are made up of multinucleate cells. Each cell is referred to as muscle fiber.