The pulmonary epithelium is a thin layer of cells lining the airways and alveoli in the lungs. It plays a crucial role in gas exchange, allowing oxygen to enter the bloodstream and carbon dioxide to be expelled. This epithelium consists of various cell types, including ciliated cells, goblet cells, and type I and type II alveolar cells, each serving specific functions in maintaining lung health. Additionally, the pulmonary epithelium acts as a barrier to pathogens and harmful particles. It produces mucus to trap debris and contains immune cells that help protect against infections. Proper functioning of the pulmonary epithelium is essential for respiratory health and overall well-being.