Ch. 7.5 Muscular System Key terms
Abduction
Movement of a limb away from the midline of the body
Adduction
Movement of a limb toward the midline of the body.
Cardiac muscle
Specialized, involuntary muscle tissue found only in the heart
Circumduction
A complex movement that combines flexion, extension, abduction, and adduction, resulting in a limb moving in a circular path
Contractility
The ability of a muscle to shorten forcefully when stimulated
Contracture
: A permanent or semi-permanent stiffening or shortening of a muscle or joint.
Dorsiflexion
Bending the foot upward at the ankle, pulling the top of the foot toward the shin.
Elasticity
The ability of a muscle to return to its original resting length after being stretched or contracted.
Excitability
The ability of a muscle to respond to a stimulus (e.g., a nerve impulse).
Extensibility
The ability of a muscle to be stretched beyond its normal resting length.
Extension
A movement that increases the angle between two body parts, essentially straightening a limb.
Fascia
A band or sheet of connective tissue that primarily attaches, encloses, and separates muscles and other internal organs.
Flexion
A movement that decreases the angle between two body parts, essentially bending a limb.
Insertion
The attachment point of a muscle on the bone that moves when the muscle contracts.
Involuntary
Refers to muscle functions not under conscious control (e.g., the beating heart or digestion).
Muscle tone
The state of partial contraction that is present in a muscle at all times, maintaining posture and readiness.
Muscular system
The organ system consisting of skeletal, smooth, and cardiac muscles that are responsible for movement, posture, and heat production
Origin
The attachment point of a muscle on the more stable or less movable bone during contraction.
Plantar flexion
Bending the foot downward at the ankle, pointing the toes and foot down
Pronation
Rotation of the forearm so that the palm faces downward or backward; also applies to the foot in certain movements.
Rotation
The circular movement of a part of the body around its long axis, such as turning the head side to side
Skeletal muscle
Voluntary muscle tissue attached to bones, responsible for body movement.
Supination
Rotation of the forearm so that the palm faces upward or forward; also applies to the foot in certain movements.
Tendons
Strong, flexible bands of connective tissue that connect muscles to bones.
Visceral muscle
Also known as smooth muscle, found in the walls of internal organs (e.g., stomach, intestines, blood vessels) and is involuntary