trace a path taken by a molecule of oxygen from the atmosphere to the blood in the pulmonary vein.what structures play role in the process by which the air moved.
Air enters the body through through the nasal cavity, into the pharynx. From the pharynx, the air moves through the larynx and into the trachea, which lead directly into the lungs.& Within the thorax, the trachea divides into two branches, the right and left bronchi& - one& bronchus entering each lung. The further branching of the bronchi is often called the bronchial tree. The bronchioles continue to subdivide until they finally end in clusters of tiny hollow air sacs or alveoli, to which air passes. Air travels to individual alveoli where oxygen diffuses across the moist, thin walls into capillaries and then into red blood cells. Being almost tripled the oxygen the blood leaving the alveoli in the pulmonary vein.The oxygen then is transported by the blood to be released to tissue cells in the body during internal respiration.& &