Physiology 2130 Lecture Notes - Lecture 2: Thin Film, Pneumothorax, Elastin

• School: Western University
• Department: Physiology
• Course: Physiology 2130
• Professor: Anita Woods

Document Summary

No air flow: intrapulmonary pressure = atmospheric pressure. Diaphragm lowers (increases volume to lower pressure) Diaphragm goes up (decrease the volume to increase pressure) A(cid:271)do(cid:373)i(cid:374)al wo(cid:396)kout ((cid:272)o(cid:374)t(cid:396)a(cid:272)t o(cid:271)li(cid:395)ue"s a(cid:374)d (cid:396)e(cid:272)tus a(cid:271)do(cid:373)i(cid:374)us) Intrapleural pressure (3mmhg: lung doesn"t collapse at the end of expiration, easy expansion of the lung (no resistance against inflation) Pressure is generated from elastic recoil forces. *always have air in lung even after exhalation (+3mmhg) Intrapulmonary p intrapleural p = transpulmonary p. This could be due to sharp onset/air leak into pleural space. Air goes out into pleural space, pushing the outside of the lung, making the lung collapse. Lung collapses (air pushes outside of lung and makes it collapse) as a result. Lung compliance: change in the lung volume due to change in lung pressure (stretchability) More compliant the lung, easier to stretch and increase in volume for inhalation. Compliance = change in lung volume / change in lung pressure.