ABSTRACT
The respiratory system consists of the lungs, conducting airways, pulmonary vasculature, respiratory muscles, and surrounding tissues and structures. Each plays an important role in influencing respiratory responses. There is also a high-pressure systemic blood delivery system to the bronchi that is completely independent of the pulmonary low-pressure circulation in healthy individuals. In diseased states, however, bronchial arteries are reported to enlarge when pulmonary blood flow is reduced, and some arteriovenous shunts become prominent. Of primary importance to lung functioning is the movement and mixing of gases within the respiratory system. The primary purpose of the respiratory system is gas exchange. In the gas exchange process, gas must use through the alveolar space, across tissue, and through plasma into the red blood cell, where it nally chemically joins to hemoglobin. The respiratory system exhibits properties of resistance, compliance, and inertance analogous to the electrical properties of resistance, capacitance, and inductance.
