Question states: Oxygen and carbon dioxide crossing between blood and air in the lungs must pass through cells of which of the following types:

 

 

CHOICE A: type I pneumocyte only

 

CHOICE B: type I pneumocyte and endothelial cells

 

So, it's a matter of if endothelial cells are included or not?

 

I am very lost..

I think it might behoove you to consider the purpose of type I pneumocytes and endothelial cells in terms of the gas exchange in your lungs..

Moved to homework help so that the question gets appropriate attention.

 

Question states: Oxygen and carbon dioxide crossing between blood and air in the lungs must pass through cells of which of the following types:

 

 

CHOICE A: type I pneumocyte only

 

CHOICE B: type I pneumocyte and endothelial cells

 

So, it's a matter of if endothelial cells are included or not?

 

I am very lost..

 

 

It might be useful for you to consider where endothelial cells and pneumocyte tissue is found and how this relates to gas exchange between alveoli and pulmonary capillaries.

Heh, you really have to hand it to some of you who ever manage to toe the line between helping and doing the work for them.