Alveolar Surface Tension – Factors Affecting Pulmonary Ventilation (Nursing)

00:01 So another force that is going to affect pulmonary ventilation is going to be alveolar surface tension.

00:09 So surface tension is the attraction of liquid molecules to one another at a gas liquid interface.

00:17 So surface tension tends to draw liquid molecules closer together and to reduce that contact with the dissimilar gas molecules.

00:29 Surface tension also resists any force that tends to increase the surface area of a liquid.

00:37 So when we think of water.

00:39 Water has a very high surface tension because of its high surface tension water normally forms drops instead of being nice and spread out and this is also the reason why sometimes when you fill up a cup if you fill it up just above the rim the water does not spill out because the water molecules are so attracted to each other that they create a very high surface tension.

01:06 Well, an alveolar fluid we also have a lot of water and so this alveolar fluid is coating the walls of our alveoli.

01:17 This would cause a tendency for the alveoli to shrink to a smaller size or possibly collapse.

01:26 To combat the surface tension of the water inour alveoli fluid instead our alveoli also produced surfactant.

01:35 Surfactant is our bodies detergent like lipid and protein complex and together it acts like a soap to reduce that surface tension of the alveolar fluid.

01:48 This prevents our alveoli from collapsing and as well it is produced by both cuboidal type two alveolar cells that are dispersed in the walls of the alveoli