Dec 24, 2013
Medical Student
1)how does surfactant help to prevent pulmonary edema?
2)quote from ganong
"an additional factor in IRDS is retension of fluid in the lungs.During fetal life ,cl- is secreted with fluid by pulmonary epithelial cells.At birth,there is a shift to Na+ absoption by these cells via ENaCs,& fluid is absorbed with Na+.Prolonged immaturity of enac contributes to pulmonary abnormalities in irds."
please elaborate iam not able to comprehend this.
3)compliance of lung varies with surface tension hence there is hysteresis.
at the peak of inspiration the alveoli is expanded and the surfactants are spread out and the rate of synthesis of surfactant cannot match and hence the density of surfactant is decreased hence it becomes less compliant.
my uestion is if there was enough surfactant i.e.rate of inflation matched with increased synthesis of surfactant can the lung expand more?


Lifetime Donor
7+ Year Member
Jan 17, 2012
Osaka, Japan
1) Pretty sure it's law of LaPlace. P = 2T/r. Surfactant decreases tension, so the collapsing pressure is lesser (i.e., the alveoli are less likely to collapse).
Your other questions aren't really succinct enough to read.