Unit 4 muscular system

abduction

movement away from midline

adduction

movment toward the midline

cardiac muscle

Type of 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

Contractibility

Property of muscles; becoming short and thick when muscle fibers are stimulated by nerves, or become short and thick; causes movement

Contracture

Tightening or shortening of a muscle

Dorsiflexion

Bending backward or bending the foot toward the knee

Elasticity

Property of muscles; allows the muscle to return to its original shape after it has contracted or stretched

Extensibility

Property of muscles; the ability to be stretched

Extension

Increasing the angle between two parts; straightening a limb

Fascia

Fibrous membrane covering, supporting, and separating muscles

Flexion

Decreasing the angle between two parts; bending a limb

Insertion

End or area of a muscle that moves when the muscle contracts

Involuntary

Independent action not controlled by choice or desire

 Muscle tone

State of partial muscle contraction providing a state of readiness to act

Muscular system

More than 600 muscles, bundles of muscle fibers held together by connective tissue

Origin

End or area of a muscle that remains stationary when the muscle contracts

Plantar flexion

Bending forward or bending the foot away from the knee

Pronation

Turning a body part downward; turning “palm down”

Rotation

Movement around a central axis; a turning

 Skeletal muscle

Type of muscle that is attached to bones and causes body movement

Supination

Turning a body part upward; turning “palm up”

Tendons

Fibrous connective tissue that connects muscles to bones

 Visceral (smooth) muscle

Type of muscle that is found in the internal organs of the body; contracts to cause movement in these organs

Voluntary

Under one’s control; done by one’s choice or desire

Excitability

Property of muscles; irritability, the ability to respond to a stimulus such as a nerve impulse