MUSCLE CELLS are elongated cells that have the ability to contract.
Muscle cells are made up of myosin and actin, which are protein filaments that slide past one another in order to produce contractions, which change the length and shape of the muscle cells. Muscles cells are largely responsible for posture, locomotion and movement of internal organs. There are there basic types of muscles; they are skeletal, cardiac and smooth muscles. Muscle cells are derived from the mesodermal layer of the embryonic germ cells. A muscle can be described as either voluntary or involuntary in action. Cardiac and smooth muscles are involuntary in action because they contract without conscious thought or effort. Skeletal muscles are voluntary in action.