The species theory, polygenism, held that human races were of different lineages and suggested a hierarchy outlined in the Chain of Being that positioned Africans between man and lower primates.
No, they are involved in the Circulatory System which is responsible for pumping and channelling blood to and from the body and lungs with heart, blood and blood vessels. no veins are not considered an organ because they are a grouping of different tissues like a organ.
Most of the veins of the body are systemic veins that convey blood from the whole body (except the lungs) to the right atrium of the heart. Each vein is a macroscopic structure enclosed in three layers of different kinds of tissue homologous with the layers of the heart. large vein that drains blood from the kidney and empties into the inferior vena cava; the renal veins lie on top of (anterior to) the renal arteries. To reach the vena cava, the left renal vein passes over the aorta and is three times as long as the right renal vein.