BASEMENT MEMBRANE

Question 1

what is the basement membrane and what does it contain?

Answer 1

Basement membranes are specialized structures located between cells and their underlying stroma or between different cell types .

Basement membranes of various tissues differ ultrastructurally, biochemically, and functionally.

All basement membranes contain an electron-dense, somewhat granular matrix of variable thickness called the lamina densa

Major components of the lamina densa include type IV collagen, laminins, and heparan sulfate proteoglycans.

Other components of the lamina densa vary depending upon the tissue type.

Question 2

function common to all basement membrane?

Answer 2

Functions common to virtually all basement membranes include
(1) substrates for cell attachment;
(2) templates for tissue repair;
(3) matrices for cell migration;
(4) substrata that influence
differentiation, morphogenesis, and apoptosis of epithelial cell layers;
(5) permeability barriers for cells and macromolecules.

Question 3

Regarding the skin where are the two major basement membranes are found?

Answer 3

In the skin, the two major basement membrane complexes are found at the epidermal–dermal interface and around the dermal microvasculature.

Question 4

what are the four main subregions of the basement membrane?

Answer 4

From superior to inferior, they are:
BASAL KERATINOCYTE
LAMINA LUCIDA
LAMINA DENSA
SUBLAMINA DENSA