Functions of pneumocytes

Question 1

Collapsing pressure

Answer 1

P=2x (surface tension)/radius

Question 2

Law of LaPlace in alveoli physiology

Answer 2

Alveoli have increased tendency to collapse on expiration as radius decreases

Question 3

Pulmonary surfactant

Answer 3

A mixture of lecithins.

The most important is diphalmitoylphosphatidylcholine.

Question 4

Surfactant synthesis

Answer 4

Around week 26th week of gestation,

but mature level not reached till 35th

Question 5

Lecithin to sphingomyelin ratio

Answer 5

> 2 in amniotic fluid indicates fetal lung maturity