CAPILLARY AND RED BLOOD CELLS (Erythrocytes) in the PLACENTA, Human 250X - Stockfoto

CAPILLARY AND RED BLOOD CELLS (ERYTHROCYTES) in the PLACENTA, Human, 250X. The capillary is constructed of ENDOTHELIUM (SIMPLE SQUAMOUS EPITHELIUM), a single layer of extremely thin cells which facilitates the diffusion of oxygen and carbon dioxide (gas exchange) at the capillary level. You can see the flattended nucleus of endothelium below the red blood cells to the left of the image. In the placenta oxygen diffuses from the maternal blood pool into the capillaries to provide oxygen to the developing embryo or fetus, whereas carbon dioxide diffuses in the opposite direction. The red blood cells are streaming through the capillary in single file formation.