Question
In cases of infant respiratory distress syndrome, there is deficiency of which lipid
| A. |
Lecithin |
| B. |
Sphingomyelin |
| C. |
Phosphatidylserine |
| D. |
Phosphatidylethanolamine |
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Correct Answer � A Explanation |
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Surfactant is a mixture of lipids (90%), proteins (8%) and carbohydrates (2%)
– Main lipid (62%) is dipalmitoyl lecithin
– Type II pneumocytes secrete surfactant
– Surfactant production starts at 20-24 weeks of fetal life and peaks between 35-37 weeks.
– It appears in amniotic fluid between 28-32 weeks of gestation
Functions of surfactant
– Prevents alveolar collapse
– Prevents pulmonary edema
– Decreases work of breathing
– Interacting with and subsequent killing of pathogens or preventing their dissemination
– Modulating immune responses.