Final answer:
Gas exchange in the respiratory system occurs in the alveoli, where inhaled oxygen is diffused into the blood and carbon dioxide is exhaled from the body.
Step-by-step explanation:
Gas exchange in the respiratory system occurs in the alveoli. The process starts when air is inhaled into the lungs through the nasal cavity, pharynx, and trachea. It then passes through the bronchi and continues into the smaller bronchioles. The final destination for the inhaled air within the respiratory system is the alveoli, small air-filled sacs located at the end of the alveolar ducts.
The walls of the alveoli are extremely thin and are surrounded by capillaries. Here, oxygen from the inhaled air diffuses into the blood, and carbon dioxide from the blood diffuses into the alveoli, which is then exhaled from the body. The alveoli provide a large surface area to maximize diffusion of gases and are the main site of the crucial exchange between oxygen and carbon dioxide.