Muscles

Skeletal
Skeletal muscle is a voluntary muscle, and has a striated (striped) appearance. It can be located along the outskirts of the bones and skeleton.

Smooth
The smooth muscle is found in the walls of our hollow organs, like the stomach and esophagus. It is an involuntary muscle and you have no control over what it does.

Cardiac
Cardiac muscle is only in one organ: The Heart. It is located in the arteries and heart, and only is there. It is also involuntary, just like you don't have to tell you heart to beat.

This is the Muscular System. The nervous system controls the actions of the muscles, although some muscles, including the cardiac muscle, can function involuntarily. Muscles make up more than half of the weight of the human body, and people who do heavy weight training often gain weight because muscle is about three times as dense as fat. Muscle are affected by weight lifting, as when you lift weights, your muscles break down. Muscles can also be affected by Muscular Dystrophy. Muscular Dystrophy is a genetic disease that damages muscle fibers. The symptoms of muscular dystrophy disease include weakness, loss of mobility and lack of coordination.The muscular system can be broken down into three types of muscles: skeletal, smooth and cardiac.

1. Is the heart a muscle?

2. Why are muscles important?