How many muscles are in the human body?
The human body has more than 600 skeletal muscles. Estimates range from about 640 to 850, depending on how small muscles and muscle groups are counted.
Skeletal muscles are the ones attached to bones that we control on purpose, such as the biceps and thigh muscles. Together they make up roughly 40 percent of an adult's body weight. They work in pairs: when one muscle contracts, its partner relaxes.
There are two other types of muscle. Smooth muscle lines organs such as the stomach, intestines and blood vessels and works automatically. Cardiac muscle is found only in the heart and never tires in the way skeletal muscle does.
Biggest and smallest
The largest muscle is the gluteus maximus in the buttocks. The longest is the sartorius, which runs down the thigh. The smallest is the stapedius in the middle ear, about a millimeter long, which helps protect the ear from loud sounds.
Did You Know?
Smiling and frowning both use many facial muscles. The face has about 40 muscles, which allow thousands of different expressions.
This answer is general information, not medical advice. For a personal health question, talk to a doctor.