Red blood cell synthesised by the kidney. Just before and after leaving the bone marrow, the developing cells are known as reticulocytes; these constitute about 1% of circulating red blood cells. The functional lifetime of a red blood cell is about 100–120 days, during which time the red blood cells are continually moved by the blood flow push (in arteries), pull (in veins) and a combination of the two as they squeeze through microvessels such as capillaries. They are also recycled in the bone marrow. The aging red blood cell undergoes changes in its plasma membrane, making it susceptible to selective recognition by
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,