Why is blood circulation in human heart called double circulation ? (CCE 2011)
Blood circulation in human heart is called double circulation as blood passes twice through the heart in order to complete one cycle—once through
right side as deoxygenated blood and once through left side as oxygenated blood. Deoxygenated blood passes to lungs. It returns to left side as
oxygenated blood. Oxygenated blood is supplied to different parts of the body. It returns to right side of the heart as deoxygenated blood.