Neuromuscular Junction

Front

What is the Neuromuscular Junction (NMJ)?

Back

The point at which a nerve cell connects with a muscle fiber, allowing for communication and muscle contraction.

Front

What is a Motor Unit?

Back

A motor unit consists of one motor neuron and all the skeletal muscle fibers it innervates.

Front

What happens when sodium is pumped into the sarcolemma?

Back

An action potential is generated, which initiates the contraction process of the muscle.

Front

What occurs at the end of the axon terminal when an action potential arrives?

Back

Calcium ions are released into the axon terminal, triggering the release of neurotransmitters.

Front

Define Synaptic Cleft.

Back

The small gap between the nerve cell and the sarcolemma of the muscle fiber where neurotransmitters are released.

Front

What role does Acetylcholine (ACh) play in muscle contraction?

Back

ACh is a neurotransmitter that transmits signals from the nerve to the muscle, initiating contraction.

Front

What is the function of neurotransmitters at the NMJ?

Back

Neurotransmitters, like ACh, facilitate communication between the nerve and muscle, leading to muscle contraction.

Front

How does the action potential travel along the muscle fiber?

Back

The action potential travels along the sarcolemma and into the T-tubules, leading to muscle contraction.

Front

What is the role of calcium ions in muscle contraction?

Back

Calcium ions bind to troponin, causing a conformational change that allows myosin to bind to actin, resulting in contraction.

Front

What happens to ACh after it has stimulated the muscle fiber?

Back

ACh is broken down by the enzyme acetylcholinesterase in the synaptic cleft, stopping the signal.