National League for Nursing (NLN PAX) Practice Exam

The respiratory system is the primary system responsible for gas exchange within the body. It facilitates the intake of oxygen from the air and the expulsion of carbon dioxide, a waste product of metabolism. This exchange occurs in the lungs, specifically in the alveoli, where oxygen diffuses into the blood while carbon dioxide diffuses out to be exhaled.

Through the process of inhalation and exhalation, the respiratory system ensures that oxygen is delivered to the bloodstream and then transported to cells throughout the body for use in cellular respiration. This is critical for maintaining the energy needs of cells and supporting overall metabolism. As the respiratory system works closely with the cardiovascular system, the transport of gases to and from tissues is efficiently managed, highlighting the essential role of the respiratory system in sustaining life.

The other systems listed do not play a direct role in gas exchange. The digestive system is primarily involved in the breakdown and absorption of nutrients, the urinary system manages waste removal and fluid balance, and the nervous system regulates bodily functions and responses but is not directly responsible for handling the exchange of gases.