AP BIOLOGY

Detailed explanation-1: -Our lungs supply oxygen from the outside air to the cells via the blood and cardiovascular system to enable us to obtain energy. As we breathe in, oxygen enters the lungs and diffuses into the blood. It is taken to the heart and pumped into the cells.

Detailed explanation-2: -Once in the lungs, oxygen is moved into the bloodstream and carried through your body. At each cell in your body, oxygen is exchanged for a waste gas called carbon dioxide. Your bloodstream then carries this waste gas back to the lungs where it is removed from the bloodstream and then exhaled.

Detailed explanation-3: -Oxygen gets into the blood through tiny blood vessels around the alveoli. Red blood cells pick up the oxygen and deliver it to the body’s cells.

Detailed explanation-4: -Every few seconds, with each inhalation, air fills a large portion of the millions of alveoli. Oxygen moves from the alveoli to the blood through the capillaries (tiny blood vessels) lining the alveolar walls. This process is called diffusion.

Detailed explanation-5: -Respiration is a chemical process of breaking down of food particles in the cells in presence of oxygen and release energy. Respiration completes in two stages, namely inspiration and expiration.