William Harvey was also an intense and dedicated observer of birds during his free time: several long and detailed passages of citations could be written delineating his observations in such places as the "Pile of Boulders" (a small island in Lancashire) and 'Bass Rock' (island off the East Coast of Scotland). William Harvey William Harvey (1 April 1578 – 3 June 1657) was an English physician who made seminal contributions in anatomy and physiology. He was the first known physician to describe completely, and in detail, the systemic circulation and properties of blood being pumped to the brain and body by the
Heart and up to 1200 bpm in the ruby-throated hummingbird. Adult amphibians and most reptiles have a double circulatory system, meaning a circulatory system divided into arterial and venous parts. However, the heart itself is not completely separated into two sides. Instead, it is separated into three chambers – two atria and one ventricle. Blood returning from both the systemic circulation and the lungs is returned, and blood is pumped simultaneously into the systemic circulation and the lungs. The double system allows blood to circulate to and from lungs which deliver oxygenated blood directly to the heart. In reptiles, the heart