Question

Why is blood circulation in human heart called double circulation?

• A. Because the blood passes through the heart twice in one complete cycle of the body
• B. Because the blood passes through the heart once in one complete cycle of the body
• C. Because the blood passes through both arteries and veins
• D. Because the blood passes through arteries, veins and capillaries

Answer 1

The correct option is A Because the blood passes through the heart twice in one complete cycle of the body

The blood circulation in human heart is called double circulation because the blood passes through the heart twice in one complete cycle of the body – once through the right half in the form of deoxygenated blood to lungs (pulmonary circulation) and next through the left half in the form of oxygenated blood to all body parts (systemic circulation).