Which tissue type lines the interior surface of blood vessels?

Which tissue type lines the interior surface of blood vessels?

• A. Endothelium (Simple Squamous)
• B. Connective Tissue
• C. Muscle Tissue
• D. Nervous Tissue

Answer: (A)

The interior surface of blood vessels is lined by endothelium, a single layer of flattened cells known as simple squamous epithelium. This endothelial lining, part of the tunica intima, provides a very smooth, low-friction surface for blood flow and helps regulate what passes through the vessel wall. It also plays active roles in controlling vessel diameter and blood clotting by releasing signaling molecules. The outer layers of vessels are made of connective tissue and smooth muscle, while nervous tissue isn’t the lining; thus endothelium best fits the function of lining the vessel interior.

The interior surface of blood vessels is lined by endothelium, a single layer of flattened cells known as simple squamous epithelium. This endothelial lining, part of the tunica intima, provides a very smooth, low-friction surface for blood flow and helps regulate what passes through the vessel wall. It also plays active roles in controlling vessel diameter and blood clotting by releasing signaling molecules. The outer layers of vessels are made of connective tissue and smooth muscle, while nervous tissue isn’t the lining; thus endothelium best fits the function of lining the vessel interior.