RT Book, Section A1 Nelson, Lewis S. A1 Odujebe, Oladapo A. A2 Nelson, Lewis S. A2 Howland, Mary Ann A2 Lewin, Neal A. A2 Smith, Silas W. A2 Goldfrank, Lewis R. A2 Hoffman, Robert S. SR Print(0) ID 1163004196 T1 Simple Asphyxiants and Pulmonary Irritants T2 Goldfrank's Toxicologic Emergencies, 11e YR 2019 FD 2019 PB McGraw-Hill Education PP New York, NY SN 9781259859618 LK accessemergencymedicine.mhmedical.com/content.aspx?aid=1163004196 RD 2024/03/29 AB The respiratory system is responsible for gas exchange, elimination of certain xenobiotics, insensible water loss, temperature regulation, and minor metabolic processes. The principal function of the respiratory system is gas exchange, which occurs in the more than 300 million alveoli that make up approximately 90% of the human lung volume. The average resting adult inhales about 8 L/min of air (a tidal volume of about 500 mL) and averages 16 breaths/min, and this volume can be increased exponentially by increasing the respiratory rate and tidal volume as occurs during exertion. In a 24-hour period, an average adult human at rest will be exposed to 11,500 L of air. There are a number of protective mechanisms within the respiratory system to prevent exposure to xenobiotics, but these mechanisms can be overwhelmed. The principles of respiratory system function are covered extensively in Chap. 28.