What are nodes of Rainvier and internodes ?

Explanation

### Step-by-Step Solution:

1. **Understanding Neuron Structure**:
- A neuron is a specialized cell that transmits nerve impulses. It consists of several parts, including the cell body, dendrites, and an axon. The axon is the elongated part of the neuron that carries impulses away from the cell body.

2. **Myelination of Axons**:
- Many axons are covered by a fatty insulating layer called the myelin sheath. This sheath is formed by glial cells and serves to speed up the transmission of electrical signals along the axon.

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