How do the lungs function during breathing?

Breathing involves inhalation and exhalation controlled by the diaphragm and chest muscles. When you inhale, air enters through the nose or mouth, travels down the trachea, and reaches the lungs. Inside, oxygen passes into the bloodstream through tiny air sacs called alveoli, while carbon dioxide moves from the blood into the lungs to be exhaled. This gas exchange provides oxygen for cellular energy and removes waste gases. The brain regulates breathing rate automatically. Pollution, smoking, or lung diseases like asthma can impair lung function and oxygen supply.