The junction between a motor neuron and the sarcolemma of the muscle fibre is :

Options

A. Neuromuscular junction
B. Synaptic cleft
C. Gap junction
D. Both (a) and (b)

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: We need to identify the name of the junction between a motor neuron and the sarcolemma of a muscle fiber.

2. **Identifying Key Components**:
- A motor neuron is a type of neuron that transmits signals to muscle fibers.
- The sarcolemma is the cell membrane of a muscle fiber.

3. **Exploring the Junction**: The connection between the motor neuron and the muscle fiber is crucial for muscle contraction and movement.

4. **Identifying the Correct Term**: The specific junction where the motor neuron communicates with the sarcolemma is known as the **neuromuscular junction**.

5. **Understanding the Function**: At the neuromuscular junction, neurotransmitters (specifically acetylcholine) are released from the motor neuron. This neurotransmitter crosses the synaptic cleft (the gap between the neuron and muscle fiber) and binds to receptors on the sarcolemma, leading to muscle contraction.

6. **Conclusion**: Therefore, the correct answer to the question is that the junction between a motor neuron and the sarcolemma of the muscle fiber is called the **neuromuscular junction**.

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