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.
Arteries carry blood from the heart to the tissues, and veins take blood back from the tissues to the heart. In a DAVF, there is a direct connection between one or more arteries and veins or sinuses which gives rise to many problems.