Algonquin College Health Program Assessment (AC-HPAT) Practice Exam

What is the main function of the respiratory system?

1. To regulate body temperature

2. To take in oxygen and eliminate carbon dioxide

3. To facilitate digestion

4. To support the immune system

The correct answer is: To take in oxygen and eliminate carbon dioxide

The main function of the respiratory system is to ensure the exchange of gases between the body and the environment, specifically by taking in oxygen necessary for cellular function and eliminating carbon dioxide, which is a waste product of metabolism. Oxygen is vital for aerobic respiration, a process in which cells extract energy from nutrients. As cells consume oxygen, they produce carbon dioxide, which must be expelled from the body to maintain proper pH levels in the blood and overall homeostasis. While the other options mention functions that relate to other bodily systems, they are not the primary roles of the respiratory system. The regulation of body temperature is primarily managed by the integumentary and circulatory systems. Digestive processes are overseen by the gastrointestinal system. Supporting the immune system involves various systems, including the lymphatic and circulatory systems, but is not the chief function of respiration. Therefore, the process of respiration highlights the critical role of oxygen intake and carbon dioxide elimination, underscoring the significance of the respiratory system in maintaining health and supporting life.