Definition of Muscle

1. 7 Most Effective Exercises Pictures
2. Take the Exercise and Fitness Quiz!
3. How to Build a Better Butt Slideshow

Muscle: Muscle is the tissue of the body which primarily functions as a source of power. There are three types of muscle in the body. Muscle which is responsible for moving extremities and external areas of the body is called "skeletal muscle." Heart muscle is called "cardiac muscle." Muscle that is in the walls of arteries and bowel is called "smooth muscle."

Need help identifying pills and medications?
Use the pill finder tool on RxList.