Tissues: The Living Fabric

– The basal lamina of the epithelial tissue and the reticular lamina of the connective tissuejoin together to form a basement membrane– The basement membrane is the interface between the epithelial tissue and the connectivetissue– Special Characteristics of Epithelium• Avascularity• Regeneration• Epithelia do not contain blood vessels but is innervated• Nutrients are obtained from the exposed or underlying surface• Epithelial cells are exposed to damage• They have the ability to regenerate and replace the cells that slough off thesurfaceClassification of Epithelia• Shape– Squamous– Cuboidal– Columnar• Degree of layering– Simple– Stratified• Simple epithelia– Consist of a single cell layer– Line surfaces used for exchange– Located in the GIT, respiratory tract, inner surface of blood vessels and heart chambers– Classification of Epithelia• Stratified epithelia– Several layer of cells (additional protection)