Muscular System Vocabulary

Anaerobic

Energy production that occurs without oxygen, typically producing ATP quickly but for a short time.

Complete tetanus

A smooth, sustained muscle contraction with no relaxation between stimuli due to rapid, repeated nerve signals.

Cross-bridges

Temporary connections formed when myosin heads attach to actin filaments during muscle contraction.

Glycolysis

The anaerobic breakdown of glucose into pyruvate to produce ATP.

Insertion

The movable end of a muscle that attaches to a bone and moves during contraction.

Isometric contraction

A muscle contraction where tension increases but muscle length does not change.

Isotonic contraction

A muscle contraction where the muscle changes length while maintaining tension

Lactic acid

A byproduct formed during anaerobic respiration when oxygen is limited.

Motor unit

A single motor neuron and all the muscle fibers it innervates.

Myofilaments

The protein filaments (actin and myosin) that make up myofibrils in muscle cells.

Myoglobin

An oxygen-binding protein in muscle fibers that stores oxygen for muscle activity.

Neuromuscular junction

The synapse between a motor neuron and a muscle fiber where nerve signals trigger contraction.

Origin

The fixed end of a muscle attached to a bone.

Prime mover

The main muscle responsible for producing a specific movement.

Sarcomere

The functional unit of a myofibril, extending from one Z line to the next.

Sarcoplasmic reticulum

A specialized smooth ER in muscle cells that stores and releases calcium ions for contraction.

Synergist

A muscle that assists the prime mover by adding force or stabilizing joints.

Tendon

A cord of dense connective tissue that attaches muscle to bone.

Transverse tubule (T-tubule)

Invaginations of the sarcolemma that conduct electrical impulses deep into the muscle fiber.