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.
Veins are classified as superficial (those that are close to the surface of the skin and have no corresponding arteries), deep (have corresponding arteries and are deeper in the body), pulmonary (that deliver oxygenated blood from the lungs to the heart) and systemic veins (that drain tissues of the body and take deoxygenated blood to the heart).