MICROANATOMY

Detailed explanation-1: -Amphibians have a three-chambered heart, which has some mixing of the blood, and they have double circulation.

Detailed explanation-2: -Humans have a double circulatory system. The heart pumps blood through two circuits: the pulmonary circulation. the systemic circulation.

Detailed explanation-3: -Double circulation describes the fact that blood flows twice in the heart before it completes one full round. One is pulmonary circulation and the other is systemic circulation. Pulmonary circulation starts from the pulmonary artery which divides into two branches which enter the respective lungs.

Detailed explanation-4: -A mechanism in which blood circulates twice through the heart in one complete cycle is known as double circulation. Systemic circulation and pulmonary circulation are two pathways in which the blood flows in double circulation. Double circulation is present in birds and mammals.