What is big in the adult lung?

The adult lung is primarily composed of alveoli, tiny air sacs where gas exchange occurs. In total, there are about 300 million alveoli in the adult lungs, which significantly increases the surface area for oxygen and carbon dioxide exchange. Additionally, the lungs contain various structures such as bronchi, bronchioles, and blood vessels that facilitate respiratory functions. Overall, the intricate architecture of the lungs is essential for effective respiration and maintaining homeostasis in the body.