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.
Organ and tissue donation involves removing organs and tissues from someone who has died (a donor) and transplanting them into someone who, in many cases, is very ill or dying (a recipient). Organs that can be transplanted include the heart, lungs, liver, kidneys, intestine and pancreas. Tissues that can be transplanted include heart valves and other heart tissue, bone, tendons, ligaments, skin and parts of the eye such as the cornea and or sclera. Heart donation.