Muscle Tissue

A collection of vocabulary flashcards derived from lecture notes on muscle tissue, covering major types, functional properties, and contraction mechanisms.

Skeletal Muscle Tissue

Striated, voluntary muscle that moves the skeleton, composed of long cylindrical multinucleated cells.

Cardiac Muscle Tissue

Striated, involuntary muscle that allows the heart to pump blood, contains short branched cells with intercalated discs.

Smooth Muscle Tissue

Non-striated, involuntary muscle found in visceral organs, characterized by spindle-shaped cells.

Excitability

The ability of muscle tissue to respond to a stimulus by changing its electrical membrane potential.

Contractility

The ability of muscle tissue to shorten in response to signals from the brain.

Elasticity

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

Tendons

Cordlike structures made of dense regular connective tissue that attach muscle to bone.

Motor Unit

A motor neuron and all the muscle fibers it controls.

Neuromuscular Junction

The site where a motor neuron innervates a muscle fiber, allowing for muscle contraction.

ACh (Acetylcholine)

A neurotransmitter that binds to receptors at the motor end plate to initiate muscle contraction.

Action Potential

A rapid change in membrane potential that propagates along the sarcolemma and T-tubules, leading to muscle contraction.

Calcium Ions (Ca2+)

Essential ions released from the sarcoplasmic reticulum that bind to troponin, triggering muscle contraction.

Myofibrils

Bundles of myofilaments (thick and thin filaments) within a muscle fiber that contract and produce force.

Sliding Filament Model

The mechanism explaining how muscle fibers shorten during contraction as myosin heads pull actin filaments.

Oxygen Debt

The amount of additional oxygen needed after exercise to restore pre-exercise conditions in the body.

Slow Oxidative Fibers

Type I muscle fibers that contract slowly and are highly fatigue-resistant, primarily relying on aerobic respiration.

Fast Glycolytic Fibers

Type IIb muscle fibers that contract quickly but fatigue rapidly, primarily relying on anaerobic respiration.

Treppe

The phenomenon where the strength of muscle twitches increases with repeated stimulation.

Isometric Contraction

A type of contraction where muscle tension increases but the muscle length remains unchanged.

Isotonic Contraction

A type of contraction where muscle tension overcomes resistance and the muscle length changes.

Fatigue

The reduced ability of muscles to produce force, often due to prolonged activity and depletion of energy reserves.

Myasthenia Gravis

An autoimmune disease characterized by weakness and rapid fatigue of voluntary muscles due to impaired ACh receptors.

Anabolic Steroids

Synthetic substances that mimic testosterone, used to enhance muscle growth and athletic performance.