The primary purpose of the respiratory system is to facilitate the exchange of gases between the body and the external environment. This system enables the inhalation of oxygen, which is crucial for cellular respiration, and the exhalation of carbon dioxide, a metabolic waste product. The primary structures involved include the nose, trachea, lungs, and alveoli. Through the process of respiration, oxygen is absorbed into the bloodstream and delivered to tissues, while carbon dioxide is expelled. This exchange is vital for maintaining bodily functions and ensuring cells receive the energy they need to operate efficiently.