Final answer:
Inhaled air comes into contact with the blood in the pulmonary circulation through the alveolar-capillary membrane, which is where the critical gas exchange of oxygen and carbon dioxide occurs.
Step-by-step explanation:
In the pulmonary system, inhaled air comes in contact with the blood of the pulmonary circulation in the alveolar-capillary membrane. The alveoli are the sites of gas exchange in the lungs. These tiny bubble-like structures are surrounded by pulmonary capillaries. The close proximity of the alveoli and the capillaries allows for efficient gas exchange through a process called simple diffusion, where oxygen enters the blood and carbon dioxide is removed. This important function is vital for oxygenating the blood that circulates throughout the body's systemic circulation.
The structure of the pulmonary system in which inhaled air comes in contact with the blood of the pulmonary circulation is the alveolar-capillary membrane. The alveoli are thin-walled sacs in the lungs where gas exchange occurs. These structures are in direct contact with the capillaries of the circulatory system, allowing oxygen to diffuse from the alveoli into the blood, and carbon dioxide to diffuse from the blood into the alveoli to be exhaled.