Which system is primarily responsible for gas exchange in the lungs?

Which system is primarily responsible for gas exchange in the lungs?

• A. Digestive system
• B. Circulatory system
• C. Respiratory system
• D. Endocrine system

Answer: (C)

Gas exchange occurs where oxygen moves from the air in the lungs into the blood, and carbon dioxide moves from the blood into the air to be exhaled. This happens in the lungs, specifically in the tiny air sacs called alveoli, which are part of the respiratory system. The walls of the alveoli and the surrounding capillaries form a very thin barrier, so diffusion can occur easily. The driving force is the partial pressure difference: oxygen is higher in the alveolar air than in the blood, so itDiffuses into the blood, while carbon dioxide is higher in the blood than in the alveolar air, so itDiffuses out into the air to be exhaled. The circulatory system plays a crucial role in transporting the blood, but the actual exchange of gases happens in the lungs. The digestive and endocrine systems do not participate in this gas exchange.

Gas exchange occurs where oxygen moves from the air in the lungs into the blood, and carbon dioxide moves from the blood into the air to be exhaled. This happens in the lungs, specifically in the tiny air sacs called alveoli, which are part of the respiratory system. The walls of the alveoli and the surrounding capillaries form a very thin barrier, so diffusion can occur easily. The driving force is the partial pressure difference: oxygen is higher in the alveolar air than in the blood, so itDiffuses into the blood, while carbon dioxide is higher in the blood than in the alveolar air, so itDiffuses out into the air to be exhaled. The circulatory system plays a crucial role in transporting the blood, but the actual exchange of gases happens in the lungs. The digestive and endocrine systems do not participate in this gas exchange.