Muscular Tissue

A set of 50 vocabulary flashcards designed to help students review key terms and concepts related to muscular tissue, as covered in their lecture.

Muscular Tissue

Type of tissue responsible for movement in the body.

Skeletal Muscle

Voluntary, striated muscle usually attached to bones; responsible for body movement.

Cardiac Muscle

Involuntary striated muscle found in the heart, responsible for pumping blood.

Smooth Muscle

Involuntary muscle found in walls of hollow organs; lacks striations.

Striations

Alternating light and dark bands found in striated muscle; caused by the organization of myofilaments.

Excitability

The ability of muscle tissues to respond to stimuli.

Contractility

The ability of muscle tissues to shorten and contract when stimulated.

Extensibility

The capacity of a muscle to be stretched beyond its resting length.

Elasticity

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

Sarcolemma

The plasma membrane surrounding a muscle fiber.

Sarcoplasm

The cytoplasm of a muscle fiber.

Myofibrils

Long, thread-like structures within muscle fibers that contain contractile proteins.

Myoglobin

Oxygen-binding protein found in muscle tissue; provides oxygen for muscle metabolism.

Sarcoplasmic Reticulum (SR)

Smooth endoplasmic reticulum in muscle cells that stores calcium ions.

T Tubules

Tubular invaginations of the sarcolemma that transmit action potentials into the muscle fiber.

Myofilaments

Filaments of myofibrils, primarily actin and myosin, involved in muscle contraction.

Thick Filaments

Myofilaments primarily composed of myosin proteins.

Thin Filaments

Myofilaments primarily composed of actin protein.

A Bands

Dark bands in striated muscle, representing areas where thick and thin filaments overlap.

I Bands

Light bands in striated muscle, containing only thin filaments.

H Band

Region in the A band where there are only thick filaments, no thin filaments.

Z Disc

Boundary between adjacent sarcomeres; anchors thin filaments.

Sarcomere

The functional contractile unit of muscle fiber; extends from one Z disc to another.

Dystrophin

Protein linking actin filaments to the muscle cell membrane; important for muscle integrity.

Motor Unit

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

Neuromuscular Junction (NMJ)

The synapse where the motor neuron communicates with the muscle fiber.

Acetylcholine (ACh)

Neurotransmitter released at the NMJ to stimulate muscle contraction.

Resting Membrane Potential

The electrical charge difference across the plasma membrane of a resting muscle cell.

Action Potential

A rapid increase and decrease in voltage across a cell membrane, leading to muscle contraction.

Tetanus

Prolonged muscle contraction without relaxation, often caused by high-frequency stimulation.

Isometric Contraction

Muscle contracts but does not change length; tension increases.

Isotonic Contraction

Muscle changes in length while maintaining tension; can be concentric or eccentric.

Anaerobic Fermentation

Pathway producing ATP in the absence of oxygen; yields lactate.

Aerobic Respiration

ATP production pathway requiring oxygen; yields much more ATP than anaerobic processes.

Muscle Fatigue

Progressive weakness and decrease in muscle effectiveness due to prolonged activity.

EPOC (Excess Postexercise Oxygen Consumption)

The elevated rate of oxygen intake following strenuous activity to restore the body.

Fast-Twitch Fibers

Muscle fibers that contract quickly and powerfully, but fatigue quickly.

Slow-Twitch Fibers

Muscle fibers that are fatigue-resistant and adapted for endurance activities.

Muscle Tone

The continuous and passive partial contraction of the muscles.

Myasthenia Gravis

An autoimmune disease that affects the neuromuscular junction, leading to muscle weakness.

Rigor Mortis

The stiffening of muscles after death due to the lack of ATP for muscle relaxation.

Muscular Dystrophy

A group of inherited disorders characterized by progressive muscle degeneration.

Cardiomyocyte

A muscle cell in the heart; responsible for contraction.

Intercalated Discs

Specialized structures in cardiac muscle that connect adjacent cardiomyocytes.

Pacemaker Cells

Cells in the heart that generate electrical impulses independently.

Calmodulin

Calcium-binding protein in smooth muscle that regulates contraction.

Stress-Relaxation Response

Smooth muscle adaptation to stretch; allows gradual accommodation to changes in volume.