Question

The blood vascular system of mammals is known as the double vascular system because:

• A. A group of arteries carries oxygenated and other groups of veins conduct deoxygenated blood.
• B. Oxygenated blood runs from the heart to different organs by one set of arteries while deoxygenated blood runs from the heart to lung by pulmonary artery.
• C. The two different systems never meet.
• D. All of the above

Answer 1

The correct option is D All of the above

Double circulation in a four chambered heart means that there are two circulations acting together in the cardio-respiratory system simultaneously. One circulation, is from the right ventricle to the lungs and back to the left atrium for oxygenation of the blood. The other circulation is from the left ventricle to the entire systemic circulation and back to the right atrium (oxygenated blood). In normal cases, the oxygenated and the de-oxygenated systems never mix.

So, the correct answer is option D.