The outer covering of non- myelinated neurons in brain is

Options

A. Neurilemma
B. Axolemma
C. Oolemma
D. Sarcolemma.

Explanation

**Step-by-Step Text Solution:**

1. **Understanding Neurons**: Neurons are the basic structural and functional units of the nervous system, found in the brain and spinal cord. They are specialized cells responsible for transmitting nerve impulses.

2. **Structure of Neurons**: Neurons consist of three main parts:
- **Dendrites**: These receive signals from other neurons.
- **Cell Body**: This contains the nucleus and organelles.
- **Axon**: This transmits signals away from the cell body to other neurons or muscles.

3. **Myelination**: Neurons can be classified as myelinated or non-myelinated based on the presence or absence of a myelin sheath. Myelinated neurons have a protective layer called the myelin sheath, which enhances the speed of signal transmission.

4. **Non-Myelinated Neurons**: In non-myelinated neurons, the myelin sheath is absent. The outer covering of these neurons is referred to as the **neurolemma**.

5. **Identifying the Correct Answer**: The question specifically asks for the outer covering of non-myelinated neurons in the brain. Since we established that this covering is called the neurolemma, the correct answer is **neurolemma**.

6. **Eliminating Incorrect Options**:
- **Exolemma**: This refers to the membrane covering of the axon but is not specific to non-myelinated neurons.
- **Oolema**: This is not a recognized term in the context of neurons.
- **Sarcolemma**: This is the membrane covering of muscle fibers, not neurons.

7. **Final Answer**: Therefore, the outer covering of non-myelinated neurons in the brain is the **neurolemma**.

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