The Muscular System

These flashcards cover key concepts and terminology related to the muscular system.

Agonist

Muscle that contracts to produce a movement.

Antagonist

Muscle that opposes the action of the agonist.

Synergist

Muscle that assists the agonist, contributing to tension.

Origin

The less movable attachment of a muscle.

Insertion

The more movable attachment of a muscle.

Erector Spinae

Muscle group that maintains posture, extends, rotates, and abducts the spine.

Pectoralis Major

Muscle that flexes, adducts, and medially rotates the arm at the shoulder.

Diaphragm

Muscle that plays a major role in breathing by depressing the floor of the thorax.

Rectus Abdominis

Muscle that depresses ribs and flexes the vertebral column.

Trapezius

Muscle that extends the head and neck, and retracts and fixates the scapula.

Flexor

Muscle that decreases the angle at a joint.

Extensor

Muscle that increases the angle at a joint.

Pronator

Muscle that pronates the forearm.

Supinator

Muscle that supinates the forearm.

Adductor

Muscle that adducts a body part.

Abductor

Muscle that abducts a body part.

Fascicles

Bundles of muscle fibers.

Biceps

Muscle with two heads of origin.

Triceps

Muscle with three heads of origin.

Quadriceps

Muscle with four heads of origin.

Muscle Fiber Orientation

Describes the arrangement of fascicles, including circular, convergent, parallel, and pennate.

Hyoid muscles

Muscles involved in chewing and swallowing.

Hamstrings

Muscles that flex the knee and extend the thigh.