Question

Who discovered the circulation of blood in a closed circulatory system?

Answer 1

Hint: In a closed circulatory system blood is accommodated inside the blood vessels. It circulates in a unidirectional manner. The scientist discovered the physiology of blood circulation in 1628.

Complete answer:
Circulatory system circulates the blood from one part of the body to another. Open and closed circulatory systems are the two circulatory systems.
Closed circulatory: Blood is circulated through the closed network of vessels of distinct size and thickness. Example: Vertebrates.
The circulation of blood in the closed circulatory system was given by William Harvey. It involves 3 circuits:
1) Coronary circulation: The supply of blood to heart walls.
a) Arteries: are thick walled which carry oxygenated blood from heart to body. It divides into tiny vessels called capillaries (smallest blood vessels where exchange of materials between blood and tissue takes place) which supply oxygenated blood to the heart.
b) Veins: It collects deoxygenated blood from the heart and puts it into the right auricle.
2) Pulmonary circulation: The circulation is between the heart and lungs. The right ventricles supply the deoxygenated blood into pulmonary aorta which arise higher and outside the heart divides into left pulmonary arteries where the blood oxygenation occurs. Via lungs the oxygenated blood returns back to the left auricle. Left auricle supplies this blood into the left ventricles.
3) Systemic circulation: The circulation occurs between the heart and body organs. The left ventricle supplies the oxygenated blood to systemic arch which further supply to body organs not lungs. The deoxygenated blood from body organs return to the right auricle. Right auricle supplies the blood into the right ventricles. It requires two circuits:
a) Arterial system: It pumps the oxygenated blood only to the body parts except lungs.
b) Venous system: It arises by the tie up of capillaries and exit at the heart’s atrium. It has superior and inferior vena cava which carry the deoxygenated blood into the right atrium.

Note: In an open circulatory system blood supply by the heart passes to the large vessels. It is typically seen in arthropods. Due to close blood vessels the blood flow is more precisely regulated in a closed circulatory system.