AP BIOLOGY

Detailed explanation-1: -The mammalian heart has double circulatory system. One system is the heart-lung-heart circulation. It carries deoxygenated blood to lungs for oxygenation. The other system is heart-body-heart circulation.

Detailed explanation-2: -It is called a double circulatory system because blood passes through the heart twice per circuit. The right pump sends deoxygenated blood to the lungs where it becomes oxygenated and returns back to the heart. The left pump sends the newly oxygenated blood around the body.

Detailed explanation-3: -Mammals and birds have a complete double circulatory system allowing oxygenated and deoxygenated blood to flow separately from each other within the heart.

Detailed explanation-4: -In mammals, the circulatory is a closed type and blood is transported through blood vessels. The heart in mammals is four-chambered with two auricles and two ventricles. Oxygenated blood from the right ventricle is carried by arteries to the whole body parts.

Detailed explanation-5: -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.