Ch. 7.5 Muscular System Key terms
moving a body part away from the midline
abduction
bending backward or bending the foot toward the knee
dorsiflexion
a tough, sheetlike membrane that covers and protects the tissue
fascia
more than 600 muscles make up the system
muscular system
attached to bones and causes the body’s movement
skeletal muscle
moving a body part toward the midline
adduction
allows the muscle to return to its original shape after it has contracted or stretched
elasticity
decreasing the angle between two bones, or being a body part
flexion
when a muscle attaches to a bone, the end that does not move
origin
turning a body part upward
supination
forms the walls of the heart and contracts to circulate blood
cardiac muscle
irritability, the ability to respond to a stimulus such as a nerve impulse
excitability
the end that moves when the muscle contracts
insertion
bending forward or being the foot away from the knee
plantar flexion
strong, tough, fibrous connective-tissue cords
tendons
moving in a circle at a joint, or moving one end of a body part in a circle while the other end remains stationary, such as swining an arm in a circle
circumduction
the ability to be streched
extensibility
cardiac muscle and visceral muscles, and they function without conscious thought or control
involuntary
turning a body part downward
pronation
also called smooth muscle, is found in the internal organs of the body, such as those of the digestive and respiratory systems, and the blood vessels and eyes
visceral muscle
a severe tightening of a flexor muscle resulting in bending of a joint
contracture
increasing the angle between two bones, or straightening a body part
extension
partial contraction, and is sometimes described as a state of readiness to act
muscle tone
turning a body part around its own axis; for example, turning the head from side to side
rotation
muscle fibers that are stimulated by nerves contract, or become short and thick, which causes movement
contractibility