Sample of spinal cord preseved in: (Repeat)
**Core Concept**
The question is testing knowledge of the techniques used to preserve and study the spinal cord, a vital structure in the central nervous system. The correct answer requires an understanding of the requirements for preserving the delicate neural tissues of the spinal cord.
**Why the Correct Answer is Right**
Formalin fixation is the gold standard for preserving the spinal cord for histopathological examination. This method involves immersing the tissue in a solution of formaldehyde, which cross-links proteins and helps maintain the structure of the neural tissues. This is essential for accurate histological evaluation, which is critical in diagnosing various spinal cord pathologies, including tumors, infections, and degenerative conditions.
**Why Each Wrong Option is Incorrect**
* **Option A:** This is incorrect because acetone fixation is not suitable for preserving the spinal cord. Acetone fixation is used for fatty tissues and would not provide the necessary preservation of neural tissues.
* **Option B:** This is incorrect because paraffin wax is used for embedding tissues after fixation, not for fixation itself. The spinal cord requires a specific type of fixation before it can be embedded in paraffin wax.
* **Option C:** This is incorrect because ethyl alcohol fixation is not commonly used for preserving the spinal cord. While ethyl alcohol can be used as a fixative, it is not the preferred method for neural tissues.
**Clinical Pearl / High-Yield Fact**
To remember the correct answer, recall that formalin fixation is essential for preserving the delicate neural tissues of the spinal cord. This is critical in diagnosing various spinal cord pathologies, including tumors, infections, and degenerative conditions.
**Correct Answer: D. Formalin fixation is essential for preserving the delicate neural tissues of the spinal cord.**