In myelinated nerve fibres, the myelin sheath is present around the

Options

A. Cell body
B. Dendrites
C. Axons
D. Synaptic knobs

Answer

To answer the question, "In myelinated nerve fibres, the myelin sheath is present around the":

1. **Understanding Nerve Fibers**: Myelinated nerve fibers are specialized structures in the nervous system that facilitate the rapid transmission of electrical impulses. They consist of neurons, which are the functional units of the nervous system.

2. **Identifying Neuron Components**: Neurons are composed of several parts:
- **Dendrites**: These receive signals from other neurons.
- **Cell Body**: This contains the nucleus and organelles.
- **Axon**: This is the long projection that transmits impulses away from the cell body.
- **Axon Terminals (Synaptic Knobs)**: These release neurotransmitters to communicate with other neurons.

3. **Role of Myelin Sheath**: The myelin sheath is an insulating layer that surrounds the axon of myelinated neurons. It is produced by Schwann cells and is crucial for speeding up the transmission of electrical impulses along the axon.

4. **Location of Myelin Sheath**: The myelin sheath is specifically found around the axon and not around the cell body, dendrites, or axon terminals. It is discontinuous, with gaps known as the nodes of Ranvier, which facilitate rapid signal transmission through a process called saltatory conduction.

5. **Conclusion**: Therefore, in myelinated nerve fibers, the myelin sheath is present around the **axon**.