Physiology of the Muscular System

These flashcards cover key concepts and terminology from the physiology of the muscular system as outlined in the lecture notes.

Excitability

The ability of muscle cells to respond to nerve signals.

Contractility

The ability of muscle cells to contract or shorten, allowing muscles to pull on bones to produce movement.

Extensibility

The ability of muscle cells to extend or stretch, allowing them to return to their resting length after contracting.

Myofibrils

Bundles of fine fibers found in muscle cells that are composed of thick and thin myofilaments.

Sarcoplasmic reticulum (SR)

A structure in muscle cells analogous to the endoplasmic reticulum, involved in calcium storage and release.

Tropomyosin

A protein that, when at rest, blocks the binding site for myosin heads on actin filaments.

Troponin

A protein that binds with calcium ions to move tropomyosin away from the binding sites on actin.

Acetylcholine

A neurotransmitter that transmits signals from neurons to muscle fibers across the synapse.

ATP (Adenosine Triphosphate)

The energy molecule required for myosin heads to bind to actin and contract muscle fibers.

Sarcomere

The structural and functional unit of a muscle fiber, defined by the pattern of thick and thin myofilaments.