Pulmonary is defined as relating to or affecting the lungs. The term “pulmonary” comes from the Latin word pulmonarius, meaning “of the lungs”. The lungs are a pair of organs located in the chest that are responsible for exchanging oxygen and carbon dioxide between the atmosphere and the bloodstream. The left lung is slightly smaller than the right lung to make room for the heart. Each lung is divided into lobes; there are three lobes in the right lung and two lobes in the left lung. The lungs are surrounded by a thin layer of tissue called pleura.
The primary function of the lungs is to exchange oxygen and carbon dioxide between the atmosphere and blood stream. This process, known as respiration, occurs through millions of tiny air sacs called alveoli. When we breathe in, air enters our nose or mouth and travels down our trachea (windpipe) to our bronchi (large airways). These branch into smaller tubes called bronchioles which end in alveoli. Oxygen diffuses across alveolar walls and enters capillaries that surround each alveolus. From here, it binds to hemoglobin molecules in erythrocytes (red blood cells) and is transported throughout our bodies where it will be used by cells for various metabolic processes such as ATP synthesis. At the same time, carbon dioxide diffuses from capillaries into alveoli where it is exhaled out of our body when we breathe out