Which system is responsible for the exchange of oxygen and carbon dioxide?

Which system is responsible for the exchange of oxygen and carbon dioxide?

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

Answer: (A)

Gas exchange of oxygen and carbon dioxide happens where air meets blood in the lungs. The respiratory system is responsible for this, because in the lungs, oxygen from the air diffuses into the blood in the alveolar capillaries, while carbon dioxide diffuses from the blood into the alveoli to be exhaled. This process is driven by differences in partial pressures of the gases. The circulatory system moves the gases around the body, but the actual swap of O2 and CO2 occurs in the lungs through the respiratory apparatus. The other systems aren’t where this gaseous exchange takes place: the digestive system processes nutrients, the nervous system controls activity and reflexes, and the circulatory system mainly transports blood and dissolved gases rather than performing the exchange itself.

Gas exchange of oxygen and carbon dioxide happens where air meets blood in the lungs. The respiratory system is responsible for this, because in the lungs, oxygen from the air diffuses into the blood in the alveolar capillaries, while carbon dioxide diffuses from the blood into the alveoli to be exhaled. This process is driven by differences in partial pressures of the gases. The circulatory system moves the gases around the body, but the actual swap of O2 and CO2 occurs in the lungs through the respiratory apparatus. The other systems aren’t where this gaseous exchange takes place: the digestive system processes nutrients, the nervous system controls activity and reflexes, and the circulatory system mainly transports blood and dissolved gases rather than performing the exchange itself.