AP BIOLOGY

Detailed explanation-1: -Oxygen-rich blood flows from the lungs back into the left atrium (LA), or the left upper chamber of the heart, through four pulmonary veins. Oxygen-rich blood then flows through the mitral valve (MV) into the left ventricle (LV), or the left lower chamber.

Detailed explanation-2: -Haemoglobin molecules inside red blood cells pick up and carry the oxygen. These oxygen-rich cells travel in the blood vessels from the lungs to the left side of the heart. The blood is then pumped around the body. Red blood cells are adapted for the transport of oxygen.

Detailed explanation-3: -The blood transports oxygen from the lungs to the cells of the body, where it is needed for metabolism. The carbon dioxide produced during metabolism is carried back to the lungs by the blood, where it is then exhaled (breathed out).

Detailed explanation-4: -Arteries carry oxygenated blood (blood that has gotten oxygen from the lungs) from the heart to the rest of the body. Blood then travels through veins back to the heart and lungs, so it can get more oxygen to send back to the body via the arteries.