abduction- moving a body part away from the midline.

adduction- moving a body part toward the midline.

cardiac muscle- forms the walls of the heart and contracts to circulate blood.

circumduction- moving in a circle at a joint, or moving one end of a body part in a circle while the other remains stationary.

contract- become short and thick which causes movement.

contractibility- muscle fibers that are stimulated such as nerve impulse.

contracture- a fixed tightening of muscle, tendons, ligaments, or skin.

dorsiflexion- bending backward or bending the foot toward the knee.

elasticity- allows the muscle to its original shape after it has contracted or stretched.

excitability- irritability, the ability to respond to a stimulus such as nerve impulse.

extensibility- the ability to be stretched.

extension- increasing the angle between two bones or straightening a body part.

fascia- tough, sheetlike membrane that covers and protects the tissue.

flexion- decreasing the angle between two bones, or bending a body part.

insertion- the end that moves when the muscle contracts.

involuntary- function without conscious thought or control.

muscle tone- state of partial contraction.

muscular system- more than 600 muscles make up the system.

origin- when a muscle attaches to the bone, the end that does not move.

plantar flexion- bending forward or bending the foot away from the knee.

pronation- turning a body part downward.

rotation- turning a body part around its own axis.

skeletal muscle- attached to bones and causes body movement.

supination- turning a body part upward.

tendons- strong, tough, fibrous connective-tissue cords.

visceral( smooth) muscle-found in the internal organs of the body.

voluntary- under conscious control muscles that we can move if we want.