Final answer:
Gas exchange between lungs and tissues, known as internal respiration, involves simple diffusion based on partial pressure differences, and takes place in the alveoli for oxygen uptake and carbon dioxide release.
Step-by-step explanation:
Gas exchange between lungs and tissues occurs via simple diffusion and depends on the difference in partial pressure of the specific gas. This process is known as internal respiration gas exchange, which occurs at the level of body tissues. Exchange of gases with the external environment, or external respiration, takes place in the alveoli of the lungs. Oxygen and carbon dioxide move in opposite directions due to their respective concentrations and partial pressures in the alveoli and the pulmonary capillaries. The anatomy of the lungs maximizes this process with a highly permeable respiratory membrane, thin capillary walls, and a large surface area.