Neuromuscular Junction and Muscle Contraction p7

Flashcards covering key vocabulary and concepts related to the neuromuscular junction and muscle contraction for exam preparation.

Neuromuscular Junction

The connection between a motor neuron and a muscle fiber, where neurotransmitters transmit signals for muscle contraction.

Electrical Synapse

A type of synapse where ions flow directly between neurons through gap junctions, allowing for fast communication.

Chemical Synapse

The most common type of synapse, specialized for the release and reception of neurotransmitters.

Acetylcholine (ACh)

A neurotransmitter that plays a crucial role in signaling muscle cells for contraction.

Synaptic Cleft

The small gap between the presynaptic neuron (axon terminal) and the postsynaptic membrane where neurotransmitters diffuse.

Exocytosis

The process by which synaptic vesicles release neurotransmitters into the synaptic cleft.

Graded Potential

Changes in membrane potential that are proportional to the strength of a stimulus and can summate in the postsynaptic cell.

End Plate Potential

A local depolarization at the neuromuscular junction, resulting from the binding of ACh to its receptors.

Repolarization

The process of restoring the membrane potential to its resting state after depolarization.

Calcium Ions (Ca2+)

Essential ions that trigger the release of neurotransmitters at synaptic terminals and are crucial for muscle contraction.

Acetylcholinesterase

An enzyme that breaks down acetylcholine in the synaptic cleft, terminating its action.

Action Potential

An electrical signal that travels along the axon and triggers neurotransmitter release at the synapse.

Excitation-Contraction Coupling

The process linking the action potential in muscle fibers to muscle contraction through the release of calcium ions.

Refractory Period

A period following an action potential during which a neuron or muscle fiber cannot be stimulated again.