The document summarizes the structure and function of the lungs. It describes that the lungs are part of the respiratory system and are responsible for bringing oxygen into the body and removing carbon dioxide. The lungs contain bronchi, bronchioles, and alveoli where gas exchange occurs. Various lung diseases and conditions are also outlined such as lung cancer, silicosis, asthma, pneumonia and COPD. Tips for maintaining healthy lungs include not smoking, exercise, and a healthy diet.