The axon is a long fibre, the distal end of which is branched. Each branch terminates as a bulb-like structure called the

Options

A. Dendrites
B. Node of Ranvier
C. Myelin sheath
D. Synaptic knob

Explanation

**Step-by-Step Solution:**

1. **Understanding the Structure of a Neuron:**
- Neurons are the basic units of the nervous system and consist of three main parts: the cell body, dendrites, and axon.

2. **Identifying the Axon:**
- The axon is a long fiber that extends from the cell body. Its primary function is to transmit electrical impulses away from the cell body to other neurons or muscles.

3. **Examining the Distal End of the Axon:**
- The distal end of the axon is where it branches out. Each of these branches is crucial for communication with other cells.

4. **Recognizing the Termination of the Axon:**
- The branches at the distal end of the axon terminate in bulb-like structures. These structures are essential for the transmission of signals to the next neuron or target cell.

5. **Identifying the Correct Term for the Bulb-like Structure:**
- The bulb-like structures at the end of the axon branches are known as **synaptic knobs** (or synaptic terminals). These knobs contain synaptic vesicles that store neurotransmitters, which are chemicals that transmit signals across the synapse to other neurons.

6. **Conclusion:**
- Therefore, the correct answer to the question is that the bulb-like structure at the distal end of the axon is called the **synaptic knob**.

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