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
Anterior spinal veins Anterior spinal veins Anterior spinal veins (also known as anterior coronal veins and anterior median spinal veins) are veins that receive blood from the anterior spinal cord. There are two major components to venous draining: the intrinsic vessels which drain first, and the pial veins which drain second. Within the intrinsic vessels are a group of veins known as central veins. These are organized into individual comb-like repetitive structures that eventually fuse together once in the ventral median spinal fissure. After their fusion the group of central veins drains its combined contents into an anterior spinal vein. These veins can