Ch. 7.5 Muscular System Key terms
Abduction
moving a body part away from the midline of the body.
Elasticity
The property of muscles that allows the muscle to return to its original shape after it has contracted or stretched.
Fascia
a tough, sheetlike membrane that covers and protects tissue; a method by which some skeletal muscles attach to bone
Extensibility
The ability of muscles to be stretched.
Muscular System
The system is composed of more than 600 muscles that provide voluntary movement, produce heat and energy, maintain posture, and protect internal organs.
Excitability
The property of muscles, also called irritability, which is the ability to respond to a stimulus such as a nerve impulse.
Skeletal Muscle
Muscle that is attached to bones and causes body movement; it is voluntary and looks striped microscopically.
Supination
Turning a body part upward
Tendons
strong, tough, fibrous connective-tissue cords that attach skeletal muscles to bones
Rotation
Turning a body part around its own axis
Contracture
A severe tightening of a flexor muscle resulting in the bending of a joint often caused by prolonged lack of use.
Voluntary
muscle action over which a person has conscious control
Visceral Muscle
muscle found in the internal organs; it is involuntary and causes movement in these organs
Muscle Tone
A state where muscles are partially contracted at all times, even when not in use; sometimes described as a state of readiness to act.
Flexion
Decreasing the angle between two bones, or bending a body part.
Plantar Flexion
Bending forward or bending the foot away from the knee.
Adduction
moving a body part toward the midline of the body
Insertion
The end of a muscle attachment that moves when the muscle contracts.
Pronation
Turning a body part downward
Origin
The end of a muscle attachment that does not move when the muscle contracts.
Contractibility
The ability of muscle fibers, when stimulated by nerves, to contract, or become short and thick, which causes movement.
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
Plantar Flexion
Bending forward or bending the foot away from the knee.
Dorsiflexion
Bending backward or bending the foot toward the knee.
Excitability
The property of muscles, also called irritability, which is the ability to respond to a stimulus such as a nerve impulse.