AP BIOLOGY

Detailed explanation-1: -Respiration involves the following steps: (i) Breathing or pulmonary ventilation by which atmospheric air is drawn in and CO2 rich alveolar air is released out. (ii) Diffusion of gases (O2 and CO2) across alveolar membrane. (iii) Transport of gases by the blood.

Detailed explanation-2: -The four steps of gas exchange are ventilation, pulmonary gas exchange, gas transport, and peripheral gas exchange. These processes describe how gas is inhaled, exhaled, exchanged at the alveoli, transported through the blood, and again diffused across cellular membranes in body tissues.

Detailed explanation-3: -Internal respiration is the process of diffusing oxygen from the blood, into the interstitial fluid and into the cells. Waste and carbon dioxide are also diffused the other direction, from the cells to the blood.

Detailed explanation-4: -Diffusion is the spontaneous movement of gases, without the use of any energy or effort by the body, between the alveoli and the capillaries in the lungs. Perfusion is the process by which the cardiovascular system pumps blood throughout the lungs.

Detailed explanation-5: -During gas exchange oxygen moves from the lungs to the bloodstream. At the same time carbon dioxide passes from the blood to the lungs. This happens in the lungs between the alveoli and a network of tiny blood vessels called capillaries, which are located in the walls of the alveoli.