Unit 7: Muscle System Practice Flashcards

A set of vocabulary flashcards covering the types of muscles, muscle cell structure, contraction physiology, major muscle names, and clinical terminology based on the unit notes.

Muscle

A bundle of fibrous tissue in a human body that has the ability to contract, producing movement in, or maintaining the position of parts of the body.

Skeletal Muscle

A voluntary, striated muscle that primarily joins to bone with tendons to enable movement and maintain posture.

Smooth Muscle

Involuntary, nonstriated muscle found in the walls of hollow organs, vessels, and respiratory passageways, such as the digestive and urinary systems.

Cardiac Muscle

Involuntary, striated muscle specific to the heart that is self-excitatory and contains intercalated disks between cells.

Sarcoplasm

The cytoplasm of a muscle fiber.

Sarcolemma

The plasma membrane of a muscle fiber.

Sarcoplasmic Reticulum

Specialized smooth endoplasmic reticulum which stores, releases, and retrieves calcium ions.

Myofibrils

Numerous parallel threadlike structures or bundles of myofilaments within muscle cells.

Myosin

Thick filaments found in myofibrils.

Actin

Thin filaments found in myofibrils.

Sarcomeres

Repeating patterns of units formed by the arrangement of myofilaments in skeletal muscle, giving it a striated appearance.

Motor Unit

A single nerve fiber and the muscle fibers it supplies.

Neuromuscular Junction

The name of the place where the motor neuron reaches the muscle cell.

Acetylcholine

The neurotransmitter chemical message that binds to receptors on the outside of the muscle fiber to initiate contraction.

Fascicles

Bundles into which muscle cells are grouped.

Endomysium

A thin layer of connective tissue that covers individual muscle cells.

Perimysium

The connective tissue layer that covers the fascicles.

Epimysium

The connective tissue that covers the entire muscle.

Tendon

A structure formed by the blending of connective tissue layers that secures the muscle to the bone.

Aponeuroses

Dense, sheet-like clusters of fibrous connective tissue to which some facial muscles are joined.

Epicranius

A facial muscle that raises the eyebrow.

Orbicularis Oculi

A facial muscle that closes the eye.

Orbicularis Oris

A facial muscle that closes and protrudes the lips.

Buccinator

A facial muscle that compresses the cheeks inward.

Zygomaticus

A facial muscle that raises the corner of the mouth.

Platysma

A muscle that draws the angle of the mouth downward and lowers the mandible.

Masseter

A facial muscle that elevates the mandible for actions like chewing.

Temporalis

A facial muscle that elevates the mandible.

Rectus Abdominis

An abdominal wall muscle that tenses the abdominal wall and flexes the vertebral column.

Pectoralis Major

A muscle of the appendicular skeleton that pulls the arm anteriorly across the chest and rotates the humerus.

Supraspinatus

A muscle that abducts the arm away from the midline.

Brachialis

A muscle that flexes the forearm at the elbow, originating from the lower half of the humerus shaft.

Biceps Brachii

A muscle that flexes the forearm at the elbow and rotates the hand laterally.

Psoas Major

A muscle that flexes the thigh, originating from the lumbar vertebral bodies.

Gluteus Maximus

The largest muscle in the buttock, responsible for extending the thigh.

Sartorius

The longest muscle in the body; it flexes the leg and thigh, abducts the thigh, and rotates the thigh laterally.

Bursitis

A condition where the small fluid-filled sacs (bursae) near joints become red and inflamed, causing pain.

Origin

The proximal attachment site of a muscle, generally the bone that remains still when the muscle contracts.

Insertion

The distal attachment site of a muscle, generally on the bone that is moved when the muscle contracts.

Brevis

A term used in muscle naming meaning short.

Longus

A term used in muscle naming meaning long.

Major

A term used in muscle naming meaning large.

Myocardium

The middle layer of the heart wall responsible for the heart's pumping action.

Cardiocytes

Individual cells that make up cardiac muscle.