Other muscles help move food through the stomach and intestines, and aid in digestion. Muscles in the heart and blood vessels force the blood to circulate. Muscles in the chest make breathing possible. Muscles are found throughout the body. As a person grows, the muscles also get bigger.
Muscle makes up nearly half the body weight of an adult.
This article primarily discusses the muscles of human beings. The last section describes muscles in other animals. The human body has more than 600 major muscles. About 240 of them have specific names. A third kind of muscle, called cardiac muscle, has characteristics of both skeletal and smooth muscles.