Interalveolar septum
=alveolar septum xEu
The alveolar lining epithelium varies in thickness, but extensive areas of it are as little as 0.05 Κm thick. The epithelium lies on a basal lamina, which, in the thin portions of
a septum, is fused with the basal lamina surrounding the adjacent capillaries.
The total barrier to diffusion between air and blood in these thin portions
may be as little as 0.2 Κm. The thick portions of a septum contain connective tissue elements, including
elastic fibres, collagen type III fibres, resident and migratory cells. (Description from Grayfs anatomy)
