The internal lining of blood vessels is called as : -

Options

A. Mesothelium
B. Endothelium
C. Pavement Epithelium
D. Stratified Epithelium

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for the specific term used to describe the internal lining of blood vessels.

2. **Identifying the Options**: The options provided are:
- Mesothelium
- Endothelium
- Pavement epithelium
- Stratified epithelium

3. **Defining Each Term**:
- **Mesothelium**: This refers to the epithelial tissue that lines the cavities of the body and covers the organs within those cavities, particularly those derived from mesoderm (like the heart and lungs).
- **Endothelium**: This is the specific term for the epithelial tissue that lines blood vessels, including arteries, veins, and capillaries.
- **Pavement Epithelium**: This is another name for squamous epithelium, which is characterized by flat, scale-like cells.
- **Stratified Epithelium**: This type of epithelium consists of multiple layers of cells, providing protection but is not specific to blood vessels.

4. **Analyzing the Correct Answer**: Since the question specifically asks for the lining of blood vessels, the term that directly refers to this is "endothelium".

5. **Conclusion**: Therefore, the correct answer to the question is **Endothelium**.

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