Muscular System - Vocabulary Review

Vocabulary flashcards from the lecture notes on the muscular system, aimed at aiding understanding and retention of key terms.

Muscles

Tissues that provide motion through contraction and relaxation.

Filaments

Protein structures within muscle fibers, primarily actin and myosin.

Skeletal Muscle

Type of muscle that is under voluntary control and striated.

Cardiac Muscle

Involuntary muscle found only in the heart, striated.

Smooth Muscle

Involuntary muscle found in internal organs, not striated.

Excitability

The ability of muscle tissue to respond to stimuli.

Contractility

The ability of muscle to shorten and generate force.

Extensibility

The ability of muscle tissue to be stretched without damage.

Elasticity

The ability of muscle to return to its original shape after being stretched.

Fasciculi

Muscle bundles that comprise skeletal muscles.

Myofibrils

Long protein bundles within muscle fibers that contain myofilaments.

Sarcoplasmic Reticulum (SR)

Smooth ER that surrounds myofibrils and stores calcium.

Neuromuscular Junction (NMJ)

The site where a motor neuron stimulates a muscle fiber.

Action Potential (AP)

An electrical signal that travels along the sarcolemma of a muscle fiber.

Troponin Complex

A small protein that binds calcium and regulates muscle contraction.

Tropomyosin

A protein that blocks active sites on actin filaments in muscle tissue.

Sliding Filament Theory

The mechanism explaining muscle contraction through overlapping filaments.

Motor Neuron

A nerve cell that connects to a muscle fiber to initiate contraction.

Motor Unit

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

Innervation Ratio

The number of muscle fibers per motor unit, affecting control and strength.