Final answer:
William Harvey was an English physician known for his pioneering work on the systemic circulation of blood through blood vessels, a milestone in the evolution of the medical understanding of human physiology.
Step-by-step explanation:
The English physician who extensively studied psychology and biology, with a particular focus on blood circulation, was William Harvey. Harvey is renowned for his detailed description of the systemic circulation and properties of blood being pumped to the brain and body by the heart, delineated in his seminal work, 'Exercitatio Anatomica de Motu Cordis et Sanguinis in Animalibus.' In this work, Harvey explained how blood travels around the body through a network of blood vessels, thanks to the rhythmic contractions of the heart.
Understanding human physiology, including knowledge of the Frank-Starling mechanism, a fundamental concept describing the relationship between the volume of blood filling the heart and the force of contraction during the heartbeat, is crucial for careers in the health professions.
Harvey's work was a significant departure from longstanding medical practices such as bloodletting, which was later shown to be ineffective and outdated as our understanding of human physiology evolved.