Step-by-step explanation:
The diffusion of gases across the lungs and capillaries is a crucial process in respiration, which is the exchange of oxygen and carbon dioxide between the body and the environment. During inhalation, oxygen-rich air enters the lungs and travels through the bronchioles and into the alveoli, which are tiny air sacs in the lungs.
In the alveoli, the oxygen molecules diffuse across the thin walls of the alveoli and into the surrounding capillaries. The capillaries are small blood vessels that are located close to the alveoli and are surrounded by a network of tiny blood vessels called arterioles. The oxygen-rich blood then travels from the lungs to the heart and is pumped to the rest of the body.
At the same time, carbon dioxide produced by cellular respiration in the body tissues diffuses from the capillaries into the alveoli, where it is exhaled during exhalation. The carbon dioxide molecules diffuse across the thin walls of the alveoli and into the surrounding air, which is then expelled from the body during exhalation.
Overall, the diffusion of gases across the lungs and capillaries is a passive process that occurs due to the concentration gradient between the air in the lungs and the blood in the capillaries. The high concentration of oxygen in the lungs and the low concentration of oxygen in the capillaries drives the diffusion of oxygen into the blood, while the high concentration of carbon dioxide in the blood and the low concentration of carbon dioxide in the lungs drives the diffusion of carbon dioxide out of the blood and into the lungs.