Significance of basal lamina for outer layers of epithelium?

Question

In stratified (not pseudostratified) epithelia such as the epidermis, what purpose does the basal lamina serve for the outer layer cells which do not even stand in contact with it?Also, how do these cells attach, all just through tight junctions to lower layers?

Answer 1

The basement membrane serves as the location for growth of the immature cells at the bottom of the epithelium. There really is no important function for the outer layers because cells grow towards the surface. The cells attach to each other via various junctions (i.e. desmosomes) that depend on the type of epithelium. The basal cells attach to the basement via interactions between membrane proteins and the basement membrane proteins.

Answer 2

The basal lamina is specialized extracellular matrix secreted by the epithelial cells. The basal lamina can be used in three key ways; 1) as an under support to epithelial cells, 2) surround cells, and 3) the separation of sheets of epithelial cells. Connections are mostly via collagen.