Endothelial Cells: The inner lining of cells in blood vessels and lymphatic vessels that provide a selectively permeable barrier between the vessel lumen and surrounding tissue.
Vasculogenesis:The process by which embryonic angioblasts form new blood vessels when there were none before.
Fetal Circulation:The circulation system in a fetus that includes unique structures not found postnatally, allowing for oxygen and nutrient exchange via the placenta