Dr. Aiswarya Vijayanalmost 6 years ago

Muscular system

The muscular system is an organ system consisting of skeletal, smooth and cardiac muscles. It permits movement of the body, maintains posture and circulates blood throughout the body. The muscular systems in vertebrates are controlled through the nervous system although some muscles can be completely autonomous.  As you have probably guessed, the main function of the muscular system is movement, but it also helps stabilize our joints, maintain our posture and generate heat during activity. Movement of our body can be voluntary and controlled by the skeletalmuscles, or it can be involuntary and controlled by smooth muscles. The muscular system is composed of specializedcells called muscle fibers. Their predominant function is contractibility. Muscles, attached to bones or internal organs and blood vessels, are responsible for movement. Nearly all movement in the body is the result of muscle contraction All muscles are made of a kind of elastic tissue. Each muscle consists of thousands, or tens of thousands, of small musculus fibers. Each musclefiber is about 40 millimeters long. It consists of tiny strands of fibrils.The 3 types of muscle tissue are cardiac, smooth, and skeletal. Cardiac muscle cells are located in the walls of the heart, appear striated, and are under involuntary control.Muscle action can be classified as being either voluntary or involuntary. Cardiac and smoothmuscles contract without conscious thought and are termed involuntary, whereas the skeletalmuscles contract upon command. Skeletal musclesin turn can be divided into fast and slow twitch fibers.