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.
Organs in the human body: Functions, location, definition of organs. An organ is a structure that contains at least two different types of tissue functioning together for a common purpose. There are many different organs in the body: the liver, kidneys, heart, even your skin is an organ. Usually there is a main tissue and sporadic tissues.