PSL201Y1 Lecture 11: PSL201 Week 11 Reading Notes
Document Summary
Psl201 week 11 part a reading notes- respiratory system lung compliance and airway resistance (pgs. 461-469) Rate of airflow into or out of the lungs is determined by: pressure gradient between atmosphere and alveoli and airway resistance. Pressure gradients: respiratory muscles and lung compliance. Lungs have high compliance, lung compliance is defined as the change in lung volume ( v) that results from a given change in trans pulmonary pressure ( p) Large lung compliance is advantageous because a smaller change in p is needed to bring in a given volume of air and therefore less work or muscle contraction is required. Elasticity: lungs are elastic due to the presence of elastic fibers in the connective tissue. Surface tension: surface tension of the lungs is caused by the air-liquid interface formed by the thin layer of fluid lining the internal surface of the alveoli. Presence of pulmonary surfactant decreases the surface tension in alveoli.
