Ch. 7.5 Muscular System Key terms
Abduction
Moving a body part away from the midline
Adduction
Moving a body part toward the midline
Cardiac Muscle
Muscle that 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 end remains stationary; like swinging an arm in a circle
Contractibility
Muscle fibers stimulated by nerve contract (become short/thick) causing movement
Contrasture
Severe tightening of a flexor muscle resulting in bending of a joint due to a lack of use
Dorsiflexion
Bending backward or bending the foot toward the knee
Elasticity
Allows the muscle to return to its original shape after contracting or stretching
Excitability
Irritability; ability to respond to stimulus like a nerve impulse
Extensibility
The ability to be stretched
Extension
Increasing the angle between two bones; straightening a body part
Fascia
Tough, sheetlike membrane that covers and protects the tissue
Flexion
Decreasing the angle between two bones; bending a body part
Insertion
The end that does move of a muscle attached to bone
Involuntary
Muscles function without conscious thought or control
Muscle Tone
Muscles are partially contracted at all times, even when not in use; this state of partial contraction is called
Muscular system
Systems of muscles in the body; more than 600 make up the system
Origin
The end that doesn’t move of a muscle attached to bone
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; turning head side to side
Skeletal Muscle
Muscle attached to bones and causes body movement
Supination
Turning a body part upward
Tendons
Strong, tough fibrous connective-tissue cords
Visceral Muscle
Smooth muscle; found in internal organs of the body like the respiratory and digestive systems, and the blood vessels and eyes; contracts to move