Q: What substance is secreted by Pneumocyte type-II cells?
-
A
Actin
-
B
Lecithin
-
C
Mucous
-
D
Lysine
B
Answer:
B
Explanation:
Pneumocyte type-II cells are located in the alveoli of the lungs and are responsible for secreting a substance called lecithin. Lecithin acts as a surfactant, which helps reduce surface tension in the alveoli, preventing them from collapsing during exhalation. Without this surfactant, the alveoli would collapse and cause difficulty in breathing. Pneumocyte type-I cells are responsible for gaseous exchange in the lungs.
Related Topic:
Share Above MCQ