Surfactant and compliance

Question 1

role of pulmonary surfactant

Answer 1

reduces surface tension on alveolar surface membrane thus reducing tendency for alveoli to collapse (recoil)

Question 2

law of Laplace

Answer 2

pressure required to keep an alveoli open is equal to 2T/r (so surfactants are more effective on smaller alveoli)

Question 3

compliance

Answer 3

change in volume relative to change in pressure (stretchability of lungs)

Question 4

factors that affect compliance

Answer 4

action of surfactant, ageing, disease

Question 5

surfactant is

Answer 5

detergent like fluid produced by type II alveolar cells

Question 6

surface tension

Answer 6

attraction between water molecules that occurs when ever there is an air water interface

Question 7

high compliance

Answer 7

large increase in lung volume for small decrease in ip pressure

Question 8

low compliance

Answer 8

small increase in lung volume for large decrease in ip pressure

Question 9

compliance is determined by

Answer 9

elastic forces, surface tension at the alveolar air liquid interface and by airway resistance