PHYSL 210 Lecture Notes - Lecture 4: Item Unique Identification, Surface Tension, Chronic Obstructive Pulmonary Disease

• School: University of Alberta
• Department: Physiology
• Course: PHYSL 210
• Professor: Dr. Saswati Das

Document Summary

For a given lung volume, less pressure is needed. When you in ate the lungs with saline, you eliminate the air-water interface. Essentially, you need that interface to need any degree of surface tension. You cannot breathe if it is fully lled with uid. Compliance is greater but you won"t breathe. Lung wants to recoil due to surface tension. All the water molecules in the depths are attracted to each other equally and oppositely. But, when you have an air water interface , the water molecules at the surface get attracted to every direction except up towards the air. Surfactant has hydrophobic tail and hydrophilic head (towards liquid) The more surfactant you have, the less number of water molecules you have there so less surface tension. Surfactant made my type 2 cells in alveoli. The very rst breath after birth is the most di cult breath ever. Lungs in utero are lled with uid (critical for development)