The respiratory system is the biological system composed of organs and structures that are responsible for taking in oxygen from the air and expelling carbon dioxide. It includes the nose, pharynx, larynx, trachea, bronchi, and lungs. The primary function of the respiratory system is to facilitate the exchange of oxygen and carbon dioxide between the blood and the air, allowing for the delivery of oxygen to the body's tissues and the removal of carbon dioxide from the body. Diseases and disorders of the respiratory system, such as asthma, chronic obstructive pulmonary disease (COPD), and lung cancer, can have a significant impact on an individual's health and quality of life. Researchers in this area study the structure and function of the respiratory system, as well as the mechanisms of respiratory diseases and potential treatments.