Which tissue type forms the inner lining of blood vessels?

Which tissue type forms the inner lining of blood vessels?

• A. Endothelium
• B. Mesothelium
• C. Epithelium
• D. Connective Tissue

Answer: (A)

The lining that directly contacts blood inside vessels is endothelial tissue, a specialized simple squamous epithelium called the endothelium. This inner layer forms the tunica intima and provides a smooth, low-friction surface that helps regulate exchange between the bloodstream and vessel wall, controls vascular tone, and helps prevent thrombosis. Mesothelium lines body cavities (like the heart, lungs, and abdomen), not blood vessels. Epithelium is a broad category of lining tissues, but the specific inner lining of vessels is endothelium. Connective tissue, meanwhile, supports and connects tissues rather than lining the vessel lumen.

The lining that directly contacts blood inside vessels is endothelial tissue, a specialized simple squamous epithelium called the endothelium. This inner layer forms the tunica intima and provides a smooth, low-friction surface that helps regulate exchange between the bloodstream and vessel wall, controls vascular tone, and helps prevent thrombosis. Mesothelium lines body cavities (like the heart, lungs, and abdomen), not blood vessels. Epithelium is a broad category of lining tissues, but the specific inner lining of vessels is endothelium. Connective tissue, meanwhile, supports and connects tissues rather than lining the vessel lumen.