Human muscle system, the muscles of the human body that work the skeletal system, that are under voluntary control, and that are concerned with movement, posture, and balance.
Muscle is a specialised soft tissue, one of the four basic types of animal tissues. There are three types of muscle tissues in vertebrates:- skeletal muscle tissue, cardiac muscle tissue, and smooth muscle tissue. Muscle tissue gives skeletal muscles the ability to contract and relax.
The size and strength of skeletal muscles are maintained or increased by regular exercise. In addition, growth hormone and testosterone help muscles grow in childhood and maintain their size in adulthood.