RT Book, Section A1 Ciccone, Charles D. A1 Bednarek, Melissa L. A1 Miller, Kenneth L. SR Print(0) ID 1188529911 T1 Respiratory Drugs T2 Pharmacology in Rehabilitation, 5e YR 2022 FD 2022 PB F. A. Davis Company PP New York, NY SN 9781719645348 LK fadavisat.mhmedical.com/content.aspx?aid=1188529911 RD 2024/04/18 AB The respiratory system is responsible for mediating gas exchange between the external environment and the bloodstream. The upper respiratory tract conducts air to the lower respiratory passages and ultimately to the lungs. It also humidifies and conditions inspired air and serves to protect the lungs from harmful substances. In the lungs, gas exchange takes place between the alveoli and the pulmonary circulation.