MEDICAL PHYSIOLOGY

Detailed explanation-1: -(a) Double circulation is characteristic of all vertebrates. (b) Blood volume in pulmonary circulation is higher than the volume of blood in systemic circulation at any instant. (c) A double aortic arch can be seen in birds and mammals.

Detailed explanation-2: -Double circulation is present in birds and mammals. They have a four-chambered heart consisting of two atria and two ventricles. The left atrium receives oxygenated blood from the lungs and is transported to the aorta through the left ventricle.

Detailed explanation-3: -Assertion-Double circulation is incomplete in amphibians and reptiles. Reason-Unlike in birds and mammals, in amphibians and reptiles, the left atrium receives oxygenated blood and the right atrium receives deoxygenated blood.

Detailed explanation-4: -Answer: The incorrect statement is (b); it occurs in all vertebrates. Explanation: When blood circulates twice through the heart during an one complete cycle, it is known as Double circulation. It is found in frogs, reptiles, birds, and mammals not in all vertebrates.