What is the primary function of the respiratory system?

What is the primary function of the respiratory system?

• A. Digesting food
• B. Oxygen transport and carbon dioxide removal via gas exchange
• C. Filtering urine
• D. Controlling hormones

Answer: (C)

Gas exchange is the key responsibility of the respiratory system. It ensures tissues get the oxygen needed for cellular respiration and that carbon dioxide, a waste product, is removed from the body. In the lungs, air reaches tiny sacs called alveoli where oxygen passes into the blood and carbon dioxide moves from the blood into the alveolar air to be exhaled. This exchange maintains blood oxygen and carbon dioxide levels and helps keep the body’s pH in balance. Other options involve different body systems: digestion by the digestive system, urine filtration by the urinary system, and hormone regulation by the endocrine system.

Gas exchange is the key responsibility of the respiratory system. It ensures tissues get the oxygen needed for cellular respiration and that carbon dioxide, a waste product, is removed from the body. In the lungs, air reaches tiny sacs called alveoli where oxygen passes into the blood and carbon dioxide moves from the blood into the alveolar air to be exhaled. This exchange maintains blood oxygen and carbon dioxide levels and helps keep the body’s pH in balance. Other options involve different body systems: digestion by the digestive system, urine filtration by the urinary system, and hormone regulation by the endocrine system.