Harvey

Part of the Circulatory System

As opposed to Galen, the workings of the heart were discovered to be more cut and dry. Below you will see the key findings of Harvey’s work on the circulation of blood.

• Heart
  Form: The heart as a whole generally consists of auricles, ventricles, and valves. Arteries and veins are connected to the heart.
  Function: The motion of the heart is that of expansion and contraction, where upon expansion blood is drawn in and where upon contraction, blood is sent out. The heart acts like a pump and is the main force behind circulation of blood throughout the body.

• Arteries and Veins
  Form: Resilient, expandable pipes
  Function: The arteries carry blood away from the heart to the lungs and other parts of the body. The veins carry blood to the heart after it has been to the lungs and other parts of the body.
  Relation to the Heart: When the heart contracts the arteries expand to support the increased volume of blood and when the heart expands the arteries relax. Likewise, the veins expand as the heart contracts. The presence of valves in veins however keeps the blood from flowing backward.

Picture depicting the presence of valves in veins.

• Auricles and Ventricles
  Form and Function: There are auricles and two ventricles in the heart. The auricles expand and contract at the same time. The ventricles expand as the auricles contract because blood from the contracting auricles is forced into the ventricles.