In a preterm baby with respiratory distress syndrome, which type of cell is deficient?
Type 1 alveolar cell
Type 2 alveolar cell
Alveolar capillary endothelial cell
Bronchial mucosal epithelial cell
Cells in Alveolar Epithelial Lining- Type I pneumocytes-Gas exchange occurs across them. .Cover 93% surface area of alveoli. Type II pneumocytes -synthesize surfactant. Direct / indirect injury to type 2 cells lead to ARDS.Cover 5%surface area of Alveoli. When there is alveolar injury, type I cells degenerate and are replaced by type II cells. Type II cells are thus responsible for regeneration of epithelium. Type I and type II pneumocytes exist in a ratio of 1:1. Type III pneumocytesact as chemoreceptors.Cover 2% surface area of Alveoli.
NEET Jan 2020