What is the primary function of the lungs?

The primary function of the lungs is to facilitate breathing and gas exchange. Lungs are the essential organs in the respiratory system that allow oxygen from the air to enter the bloodstream while simultaneously removing carbon dioxide, a waste product of metabolism, from the blood. This process of gas exchange occurs in tiny air sacs within the lungs called alveoli, where oxygen is absorbed into the blood, and carbon dioxide is released. This vital exchange supports cellular respiration, which is crucial for energy production in all body cells.

Understanding the role of the lungs highlights their significance in maintaining proper oxygen levels and overall health, making them critical to the respiratory and circulatory systems. In contrast, the other options relate to functions performed by different body systems. For example, the heart is responsible for pumping blood, glands produce hormones, and the digestive system is responsible for breaking down food. The unique role of the lungs underscores their importance in the body's respiratory function.