Pt3

Neuromuscular Junction (NMJ)

The synapse between a motor neuron and a muscle fiber where signal transmission occurs.

Acetylcholine (ACh)

A neurotransmitter released at the neuromuscular junction that stimulates muscle contraction.

Synaptic Clef

The space between the axon terminal and the muscle fiber in the neuromuscular junction.

Motor End Plate

The specialized region of the muscle plasma membrane where neurotransmitter receptors are located.

End Plate Potential

Localized depolarization at the motor end plate due to influx of sodium ions.

Ligand Gated Sodium Channel

Channel that opens in response to the binding of acetylcholine allowing sodium to enter the muscle fiber.

Calcium Ion Channels

Channels that open in response to depolarization, allowing calcium to flow from the sarcoplasmic reticulum into the cytoplasm.

Excitation-Contraction Coupling

The process linking the action potential in the muscle fiber to the contraction process.

Crossbridge Cycle

The sequence of events during muscle contraction involving the binding of myosin to actin and the sliding of filaments.

Acetylcholine Esterase

Enzyme that breaks down acetylcholine in the synaptic cleft to terminate its action.