In 1616, William Harvey proposed a theory that explained how blood circulates through the body. Harvey was an English physician who studied medicine at Cambridge and the University of Padua. His work was based on observation, dissection and experiments rather than only on the writings of earlier authorities. He concluded that blood moves from the heart through the arteries and returns through the veins. He later published his findings in 1628. His work challenged ideas linked to Galen and changed the study of anatomy and physiology. It also helped establish observation and experimentation as methods for studying the human body.
