Nucleus pulposus represents

Options

A. Remains of notochord
B. Area of ossification
C. Region of non-ossification
D. Area resistant to frictional damage.

Answer

**Step-by-Step Solution:**

1. **Understanding the Nucleus Pulposus:**
- The nucleus pulposus is a crucial part of the intervertebral discs in mammals. It is located at the center of these discs and is composed of a jelly-like substance.

2. **Composition of Nucleus Pulposus:**
- This jelly-like substance primarily consists of water and a loose network of collagen fibers. This unique composition allows it to provide flexibility and support.

3. **Function of Nucleus Pulposus:**
- The main function of the nucleus pulposus is to help the vertebral discs withstand compression and torsion. This is vital for maintaining the integrity and functionality of the spine.

4. **Analyzing the Options:**
- **Option A:** Remains of notochord - This is correct, as the nucleus pulposus is indeed derived from the notochord, which is a primitive structure in the embryonic development of vertebrates.
- **Option B:** Area of ossification - This is incorrect. The nucleus pulposus does not represent an area of ossification.
- **Option C:** Region of non-ossification - This is also incorrect, as it does not accurately describe the nucleus pulposus.
- **Option D:** Area resistant to frictional damage - This is incorrect because the primary function of the nucleus pulposus is not related to friction resistance.

5. **Conclusion:**
- Based on the analysis of the options, the correct answer is **A: remains of notochord**.

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