AP BIOLOGY

Detailed explanation-1: -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.

Detailed explanation-2: -Gas Exchange in the Lung The intimate association of alveoli with capillaries facilitates exchange of oxygen and carbon dioxide between blood and inspired air inside the alveoli. Inspired air is a mixture of nitrogen (79%), oxygen (21%), carbon dioxide (0.03%), and a variety of other gases.

Detailed explanation-3: -Gas Exchange Between Alveolar Spaces and Capillaries The function of the respiratory system is to move two gases: oxygen and carbon dioxide. Gas exchange takes place in the millions of alveoli in the lungs and the capillaries that envelop them.

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: -The alveoli are where the lungs and the blood exchange oxygen and carbon dioxide during the process of breathing in and breathing out. Oxygen breathed in from the air passes through the alveoli and into the blood and travels to the tissues throughout the body.