Muscular System

Flashcards covering key vocabulary and concepts related to the muscular system, crucial for understanding key terms and mechanisms in muscle physiology.

Myostatin

A protein that inhibits muscle growth; mutations can lead to increased muscle size.

Skeletal Muscle Fiber

A single elongated muscle cell that contracts in response to stimulation.

Neuromuscular Junction

The site where a motor neuron communicates with a muscle fiber, releasing neurotransmitters.

Muscle Hypertrophy

The enlargement of muscle fibers, often due to increased physical activity or resistance training.

Sliding Filament Model

The theory that explains muscle contraction as the sliding of actin and myosin filaments past each other.

Acetylcholine (ACh)

A neurotransmitter released by motor neurons that stimulates muscle contraction.

Motor Unit

A motor neuron and all the muscle fibers it stimulates, functioning together as a unit.

Calcium Ions (Ca2+)

Ions released from the sarcoplasmic reticulum during muscle contraction, essential for enabling actin and myosin interactions.

Oxygen Debt

The amount of oxygen required to remove lactic acid following strenuous exercise and to restore ATP levels.

Fascia

A sheet of connective tissue that surrounds muscles and separates them from other tissues.

Tetanic Contraction

A sustained muscular contraction resulting from a rapid series of stimuli.

Striations

Alternating light and dark bands in skeletal muscle fibers, resulting from the organization of actin and myosin.

Resistance Training

A form of exercise that improves muscle strength and endurance through progressive overload.

Muscle Fatigue

The temporary inability of a muscle to contract effectively due to prolonged activity.

Tendinitis

Inflammation of a tendon, often due to overuse or repeated stress.

Epimysium

The outer connective tissue layer that surrounds an entire skeletal muscle.

Perimysium

The connective tissue that surrounds bundles of muscle fibers called fascicles.

Sarcoplasm

The cytoplasm of a muscle cell, containing organelles and the resources necessary for contraction.

Troponin

A protein that binds calcium and allows muscle contraction by enabling actin and myosin interaction.

Tropomyosin

A protein that blocks myosin binding sites on actin filaments in the absence of calcium ions.

Creatine Phosphate

A molecule that stores high-energy phosphates in muscle cells and can quickly regenerate ATP during muscle contraction.

Aponurosis

A broad, flat layer of connective tissue that connects muscles to the parts they move.

Latent Period

The time interval between the application of a stimulus and the beginning of a muscle contraction.

Sarcomere

The basic functional unit of striated muscle fibers, consisting of actin and myosin between Z lines.

Tetanus

A state of sustained muscle contraction due to rapid stimulation.