Respiratory physiology is the study of how the body takes in oxygen and expels carbon dioxide. This process begins when air enters the lungs through the trachea and branches into smaller airways called bronchi and bronchioles. In the lungs, oxygen from the air passes into the blood through tiny air sacs called alveoli, while carbon dioxide moves from the blood into the alveoli to be exhaled. The efficiency of this gas exchange is influenced by factors such as lung volume, breathing rate, and the partial pressures of gases. Proper functioning of the diaphragm and other respiratory muscles is essential for effective breathing, ensuring that the body receives the oxygen it needs for energy and removes waste gases.