Explain how we breathe air in and out?

Breathing involves two main processes: inhalation and exhalation. During inhalation, the diaphragm and intercostal muscles contract, expanding the chest cavity and creating a vacuum that draws air into the lungs. Oxygen from the inhaled air is then exchanged for carbon dioxide in the blood. During exhalation, the diaphragm relaxes, the chest cavity decreases in size, and carbon dioxide is expelled from the lungs.