Which among the following is remnant of notochord?
## **Core Concept**
The notochord is a significant embryological structure that provides the primary axial support in the earliest stages of chordate development. It is a precursor to the vertebral column and induces the formation of the neural tube. Remnants of the notochord in adults are primarily found in the intervertebral discs.
## **Why the Correct Answer is Right**
The nucleus pulposus of the intervertebral discs is directly derived from the notochord. During embryonic development, the notochord induces the formation of the vertebral column and eventually gets replaced by the vertebral bodies and the intervertebral discs. However, a remnant of the notochord persists in the center of each intervertebral disc, forming the **nucleus pulposus**. This structure provides the cushioning effect between adjacent vertebrae.
## **Why Each Wrong Option is Incorrect**
- **Option A:** This option is incorrect because it does not accurately represent a remnant of the notochord. Without the specific content of option A, we acknowledge that only one option correctly represents a notochord remnant.
- **Option B:** Similarly, this option does not correctly identify a remnant of the notochord.
- **Option D:** This option is also incorrect as it does not accurately describe the remnant of the notochord.
## **Clinical Pearl / High-Yield Fact**
A key clinical correlation is that the **nucleus pulposus** can herniate, leading to conditions such as lumbar or cervical disc herniation, which can compress spinal nerves and cause pain or neurological deficits. Understanding the embryological origin of the nucleus pulposus from the notochord helps in appreciating its function and the potential for herniation.
## **Correct Answer:** C. Nucleus pulposus.