Circulatory system the areas above the heart) and the inferior vena cava (roughly speaking from areas below the heart). These two great vessels empty into the right atrium of the heart. The heart itself is supplied with oxygen and nutrients through a small "loop" of the systemic circulation and derives very little from the blood contained within the four chambers. The general rule is that arteries from the heart branch out into capillaries, which collect into veins leading back to the heart. Portal veins are a slight exception to this. In humans the only significant example is the hepatic portal vein which
Face transplant the sinuses around the nose, the upper jaw, and even some teeth from a brain-dead donor. As doctors recovered the donor's facial tissue, they paid special attention to maintaining arteries, veins, and nerves, as well as soft tissue and bony structures. The surgeons then connected facial graft vessels to the patient's blood vessels in order to restore blood circulation in the reconstructed face before connecting arteries, veins and nerves in the 22-hour procedure. She had been disfigured to the point where she could not eat or breathe on her own as a result of a traumatic injury several years ago,