What is the primary function of the respiratory system?

• A. To facilitate digestion of food
• B. To facilitate gas exchange between the body and the environment
• C. To regulate body temperature
• D. To produce hormones

Answer: (B)

The primary function of the respiratory system is to facilitate gas exchange between the body and the environment. This involves the intake of oxygen (O2) from the atmosphere and the removal of carbon dioxide (CO2), a waste product of metabolism, from the bloodstream. The respiratory system includes components such as the lungs, trachea, and alveoli, which work together to ensure that oxygen is delivered to the tissues and organs while carbon dioxide is expelled. This exchange is vital for maintaining cellular function and overall homeostasis within the body.

Understanding this fundamental role highlights the importance of the respiratory system in sustaining life, as all cells require a constant supply of oxygen for aerobic respiration, which generates energy.