Neuromuscular Junction

Front

What is a motor unit?

Back

A motor unit consists of one neuron and all the skeletal muscle cells it stimulates.

Front

What neurotransmitter stimulates skeletal muscle movement?

Back

Acetylcholine (ACh) is the specific neurotransmitter that stimulates the movement of skeletal muscles.

Front

What is the neuromuscular junction (NMJ)?

Back

The neuromuscular junction (NMJ) is the point at which the nerve cell reaches the sarcolemma of the muscle fiber.

Front

What happens when sodium is pumped into the sarcolemma?

Back

An action potential is transferred to the sarcolemma to start the process of contraction.

Front

What occurs when ACh binds to receptor cells on the sarcolemma?

Back

The sarcolemma becomes temporarily permeable to sodium.

Front

Define synaptic cleft.

Back

The synaptic cleft is the small gap between the axon terminal of a neuron and the muscle fiber.

Front

What role does calcium play in muscle contraction?

Back

Calcium is released into the muscle fiber to facilitate the contraction process.

Front

What is the function of acetylcholinesterase?

Back

Acetylcholinesterase breaks down acetylcholine in the synaptic cleft, stopping the signal for muscle contraction.

Front

Explain the role of the sarcolemma in muscle contraction.

Back

The sarcolemma is the cell membrane of a muscle fiber that becomes depolarized when sodium enters, leading to muscle contraction.

Front

What is the significance of action potential in muscle contraction?

Back

Action potential is essential for initiating the contraction process in muscle fibers.