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 striated, involuntary muscle that forms the walls of the heart.
Circumduction
Movement of a limb in a circular manner, describing a cone shape.
Contractibility
The ability of a muscle to shorten forcefully when adequately stimulated.
Contracture
A severe tightening of a muscle resulting in a permanent immobility of the joint.
Dorsiflexion
Bending the foot upward toward the shin (decreasing the angle between the foot and leg).
Elasticity
The ability of a muscle to return to its original length after being stretched or shortened.
Excitability
The ability of a muscle to receive and respond to a stimulus.
Extensibility
The ability of a muscle to be stretched or extended.
Extension
Increasing the angle between two bones, often straightening a joint
Fascia
A sheet or band of fibrous connective tissue that covers, separates, or binds together muscles, organs, and other soft structures of the body.
Flexion
Decreasing the angle between two bones, often bending a joint.
Insertion
The point of attachment of a muscle to the bone that it moves (the more movable end).
Involuntary
Functions without conscious control (e.g., cardiac and visceral muscle).
Muscle tone
A state of slight continuous contraction of muscles, which helps maintain posture.
Muscular system
The body system composed of all the muscles that permit movement of the body, maintain posture, and circulate blood.
Origin
The point of attachment of a muscle to the bone that is less movable (the fixed end).
Pronation
Rotation of the forearm so the palm faces downward or backward.
Rotation
Turning a bone on its own axis.
Skeletal muscle
Striated, voluntary muscle that attaches to bones and produces movement.
Supination
Rotation of the forearm so the palm faces upward or forward.
Tendons
Tough, cord-like bands of connective tissue that connect muscles to bones.
Visceral muscle
Non-striated, involuntary muscle found in the walls of internal organs (also called Smooth muscle).
Voluntary
Functions under conscious control (e.g., skeletal muscle).