Blood circulation in the human heart is called double circulation because blood passes through the heart twice during one complete cycle of circulation. This happens because the heart is divided into two separate circulatory pathways: one for oxygenated blood (systemic circulation) and one for deoxygenated blood (pulmonary circulation).
Here’s a more detailed explanation:
Systemic Circulation:
This pathway carries oxygenated blood from the heart to the rest of the body, where oxygen is delivered to the tissues and carbon dioxide is picked up. The deoxygenated blood then returns to the heart.
Pulmonary Circulation:
This pathway carries deoxygenated blood from the heart to the lungs, where it is reoxygenated. The oxygenated blood then returns to the heart.
Because blood passes through the heart twice during this complete cycle, it’s called double circulation. This system ensures that the oxygenated blood is efficiently distributed throughout the body, and the deoxygenated blood is effectively reoxygenated in the lungs.