Neuromuscular Junction and Muscle Contraction

A set of vocabulary flashcards covering key terms related to the neuromuscular junction and muscle contraction.

Neuromuscular Junction (NMJ)

A specialized synapse between a somatic motor neuron's nerve terminal and the motor end plate of a skeletal muscle cell.

Excitation/Contraction (E/C) Coupling

The process where an action potential in the muscle cell membrane is transformed into muscle contraction.

Myofiber

A muscle fiber that contains myofibrils and is surrounded by the sarcolemma.

T-tubules

Transverse tubules that invaginate the myofibrils and are continuous with the sarcolemma.

Sarcoplasmic Reticulum (SR)

A network of interconnected sarcotubules that surrounds myofibrils and stores calcium ions.

Terminal Cisternae

Regions of the sarcoplasmic reticulum that are closely apposed to T-tubules.

Motor Unit

A motor neuron and all the muscle fibers it innervates, functioning as a single unit.

Sliding Filament Model of Contraction

A model that describes muscle contraction based on the sliding movement of actin and myosin filaments.

Dihydropyridine Receptors (DHPR)

Voltage-gated receptors located in the T-tubules that play a critical role in excitation/contraction coupling.

Ryanodine Receptors (RyR)

Calcium release channels in the sarcoplasmic reticulum that are activated during excitation/contraction coupling.