What is the primary organ responsible for breathing in humans?

The primary organ responsible for breathing in humans is the lungs. The lungs are vital for the respiratory system, as they facilitate the exchange of gases—specifically oxygen and carbon dioxide. When a person inhales, air enters the lungs where the oxygen is absorbed into the bloodstream and transported to cells throughout the body. At the same time, carbon dioxide, which is a waste product of metabolism, is expelled from the blood and released into the air when a person exhales. This essential function enables the body to maintain adequate oxygen levels and remove carbon dioxide, which is crucial for survival.

In contrast, the heart is primarily responsible for pumping blood throughout the body; the liver plays a key role in metabolic processes and detoxification; and the stomach is involved in digestion, breaking down food for nutrient absorption. While all these organs are vital to overall health, none are directly involved in the act of breathing like the lungs are.