Kaplan Nursing Entrance Practice Exam 2026 – The All-in-One Guide to Exam Success!

Alveoli are tiny air sacs located within the lungs and are crucial components of the respiratory system. They are primarily responsible for gas exchange, allowing oxygen to enter the bloodstream while carbon dioxide is removed from it. Each alveolus is surrounded by a network of capillaries, which facilitates this exchange between the air within the alveoli and the blood. This process is essential for maintaining proper oxygen levels in the body and supporting cellular metabolism.

In contrast, the other systems mentioned have different roles and do not directly involve alveoli. The circulatory system is responsible for transporting blood, nutrients, and waste products, but it does not include alveoli. The digestive system is involved in breaking down food and assimilating nutrients but is not related to the function of alveoli. Lastly, the nervous system controls and coordinates bodily functions but does not have a direct role in the gas exchange process carried out by the alveoli.