NEET PG DENTAL EXAM

Detailed explanation-1: -Capillaries are the smallest of blood vessels. Their walls consist of a single layer of endothelial cells and the smallest have a single endothelial cell wrapped around to join with itself. These permit a single red blood cell to pass through them but only by deforming itself.

Detailed explanation-2: -Capillaries are the connection of the smallest branches of arteries and veins. The capillary walls are one cell thick. Capillaries allow molecules to pass through across the capillary walls. This exchange of materials is not possible across the walls of other types of blood vessels because the walls are too thick.

Detailed explanation-3: -Capillary walls consist of a single layer of flattened endothelial cells, the endothelia, and these cells constitute the barrier between the blood and the ISF. Electron microscopy has revealed that endothelial cells in different tissues are of two distinct types: “continuous” and “fenestrated” (Figure 9.1).