The pulmonary capillary network is located where?

The pulmonary capillary network is located where?

• A. In the walls of the alveoli
• B. In the heart chambers
• C. In the trachea
• D. In the pleural space

Answer: (A)

Gas exchange happens most efficiently where blood is in immediate contact with air. The pulmonary capillary network sits in the walls of each alveolus, forming the alveolar-capillary membrane. This ultra-thin barrier places blood right next to the air-filled alveolar space, allowing oxygen to diffuse into the blood and carbon dioxide to diffuse out. The capillaries are part of the pulmonary circulation and are designed with very thin walls to minimize the diffusion distance. Other structures serve different roles: heart chambers contain the pumping muscle of the heart, the trachea is an airway for moving air, and the pleural space is a lubricated gap around the lungs. Thus, the network resides in the walls of the alveoli.

Gas exchange happens most efficiently where blood is in immediate contact with air. The pulmonary capillary network sits in the walls of each alveolus, forming the alveolar-capillary membrane. This ultra-thin barrier places blood right next to the air-filled alveolar space, allowing oxygen to diffuse into the blood and carbon dioxide to diffuse out. The capillaries are part of the pulmonary circulation and are designed with very thin walls to minimize the diffusion distance.

Other structures serve different roles: heart chambers contain the pumping muscle of the heart, the trachea is an airway for moving air, and the pleural space is a lubricated gap around the lungs. Thus, the network resides in the walls of the alveoli.