Seeley's Anatomy & Physiology Chapters 9 & 10 Practice Flashcards

A comprehensive set of vocabulary flashcards covering the anatomy, physiology, and clinical aspects of the muscular system based on Seeley's Anatomy & Physiology Chapters 9 and 10.

Fascia

Connective tissue that surrounds muscles and compartments.

Epimysium

The connective tissue layer that surrounds the entire muscle.

Perimysium

The connective tissue layer that surrounds fascicles.

Endomysium

The connective tissue layer that surrounds individual muscle fibers.

Aponeuroses

Broad, flat tendons that attach muscle to other structures.

Sarcomere

The functional contractile unit of a muscle fiber.

Excitability

A property of muscle tissue that allows it to respond to a stimulus.

Contractility

The ability of a muscle to shorten forcefully.

Extensibility

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

Elasticity

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

Acetylcholine (ACh)

The neurotransmitter released by exocytosis at the neuromuscular junction to trigger muscle depolarization.

Acetylcholinesterase

The enzyme that rapidly breaks down $ACh$ in the synaptic cleft to stop muscle stimulation.

T-tubules

Invaginations of the sarcolemma that allow action potentials to travel deep into the muscle fiber.

Sarcoplasmic reticulum

The specialized endoplasmic reticulum in muscle cells that stores and releases calcium.

Troponin

The protein on the actin filament that binds calcium, causing a conformational change.

Tropomyosin

The protein that blocks actin binding sites at rest and moves when calcium binds to troponin.

Power stroke

The action where the myosin head pulls the actin filament toward the center of the sarcomere.

I band and H zone

The specific regions of the sarcomere that shorten during muscle contraction.

Creatine phosphate

The fastest source of $ATP$ available for muscle contraction.

Isometric contraction

A type of contraction where tension is generated but the muscle does not change length.

Isotonic concentric contraction

A contraction where the muscle produces force while shortening.

Isotonic eccentric contraction

A contraction where the muscle produces force while lengthening.

Motor Unit

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

Type I fibers

Slow oxidative muscle fibers that are resistant to fatigue.

Type IIa fibers

Fast oxidative-glycolytic muscle fibers.

Type IIx fibers

Fast glycolytic muscle fibers that are the strongest but fatigue the fastest.

Myasthenia gravis

A clinical condition characterized by a reduction in functional $ACh$ receptors.

Botulinum toxin

A toxin that causes paralysis by blocking the release of $ACh$.

Rigor mortis

A state of muscle rigidity after death caused by the absence of $ATP$, which prevents myosin from detaching from actin.