Structure of External and Internal Lining Tissues

All of these structures have an epithelial lining that lies at the interface as well as extracellular matrix including basement membranes and loose connective tissue that supports the cellular layers (Table 3.2). These tissues are similar in their general structure they all have an inner cellular layer, supportive connective tissue, and an outer cellular layer. It is important to be familiar with the structure of these tissues to be able to analyze how external and internal mechanical forces are transduced at both the macroscopic and microscopic level into and out of cells. The effect of mechanical loading on these tissues is complex, but as discussed above, with increased frictional forces on the epidermis, the surface layer of skin actually increases the thickness of the epidermis. 

Structure Cellular layers Noncellular layers Function 

Alveolus Squamous epithelium Basement membrane Lines inside of alveolus 

Mouth Posterior epithelium Stratified squamous Descemet s membrane Controls fluid transport 

Submucosa Blood vessels Nerves and fat Connective tissue Provides nutrition 

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