Which is a main function of the respiratory system?

Which is a main function of the respiratory system?

• A. Immune response
• B. Digestion
• C. Hormone production
• D. Gaseous exchange

Answer: (D)

Gas exchange is the main function of the respiratory system. It’s about getting oxygen into the body for cellular respiration and removing carbon dioxide, a waste product, from the blood. In the lungs, oxygen from the air diffuses across the thin walls of the alveoli into the surrounding capillaries, where it binds to hemoglobin for transport to cells. Meanwhile, carbon dioxide diffuses from the blood into the alveolar air to be exhaled. This process relies on diffusion driven by differences in gasPartial pressures and occurs across a large surface area of the alveolar-capillary membrane, making it efficient for meeting the body's oxygen needs and removing CO2. Other options describe functions belonging to different systems: immune response is handled by the immune system, digestion by the digestive system, and hormone production by the endocrine system. These are not the primary roles of the respiratory system.

Gas exchange is the main function of the respiratory system. It’s about getting oxygen into the body for cellular respiration and removing carbon dioxide, a waste product, from the blood. In the lungs, oxygen from the air diffuses across the thin walls of the alveoli into the surrounding capillaries, where it binds to hemoglobin for transport to cells. Meanwhile, carbon dioxide diffuses from the blood into the alveolar air to be exhaled. This process relies on diffusion driven by differences in gasPartial pressures and occurs across a large surface area of the alveolar-capillary membrane, making it efficient for meeting the body's oxygen needs and removing CO2.

Other options describe functions belonging to different systems: immune response is handled by the immune system, digestion by the digestive system, and hormone production by the endocrine system. These are not the primary roles of the respiratory system.