Which tissue type lines the interior of blood vessels?

Which tissue type lines the interior of blood vessels?

• A. Simple squamous epithelium
• B. Endothelium of blood vessel
• C. Stratified squamous epithelium
• D. Pseudostratified ciliated columnar epithelium

Answer: (B)

The interior of blood vessels is lined by endothelium, a single layer of flat endothelial cells. This makes it a specialized form of simple squamous epithelium. The name endothelium specifies the exact location—the lining inside vessels—so it’s the best choice. This smooth, thin layer reduces friction for flowing blood and regulates exchange between blood and the vessel wall. While simple squamous epithelium describes the cell type, endothelium specifically identifies the tissue that lines the vessels, distinguishing it from other locations lined by different epithelia (like stratified squamous in skin or mucosa, or pseudostratified ciliated columnar in the respiratory tract).

The interior of blood vessels is lined by endothelium, a single layer of flat endothelial cells. This makes it a specialized form of simple squamous epithelium. The name endothelium specifies the exact location—the lining inside vessels—so it’s the best choice. This smooth, thin layer reduces friction for flowing blood and regulates exchange between blood and the vessel wall. While simple squamous epithelium describes the cell type, endothelium specifically identifies the tissue that lines the vessels, distinguishing it from other locations lined by different epithelia (like stratified squamous in skin or mucosa, or pseudostratified ciliated columnar in the respiratory tract).