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.
Blood is a fluid connective tissue that performs many functions in the body. It carries oxygen and nutrients to the cells, hormones (chemical messengers) to the tissues, and waste products to organs that remove them from the body.