EPITHELIAL TISSUES Learning Goals 1 Describe the characteristics of epithelium that distinguish it from other types of tissues 2 Describe structural classifications of epithelial tissue by layering simple or stratified 3 Illustrate epithelial tissues by shape squamous cuboidal or columnar 4 List epithelial types and their function 5 Predict which epithelial cell type you would expect to find in an organ given the tissue functions 6 Name the specialized structures associated with the lateral basal and apical surfaces of epithelial cells Outline I Special Characteristics of epithelial tissues A Cellularity B Cell junctions C Polarity i apical surface ii basal surface D Supported by connective tissue E Avascular F Innervated G Regeneration II Epithelial cell surface features A Lateral surface features i cell junctions tight junctions desmosomes gap junctions B Basal surface feature i basal lamina C Apical surface features i microvilli ii cilia III Major categories 1 membranous majority of body coverings linings 2 glandular specialized tissue for glandular secretions IV Epithelium membranous A Functional generalities Think about as we talk about different systems 1 if covering or lining surface protection from pathogens physical injury toxins dessication 2 3 4 5 lining GI tract absorption kidneys filtration pulmonary alveoli lungs diffusion of gases taste buds chemoreception B Classification system of epithelia based on of cell layers shape of cells along apical layer i of Layers 1 simple single layer 2 stratified multiple layers ii Shapes of cells 1 squamous flattened cell 2 cuboidal cube shaped 3 columnar tall C Simple epithelial tissue i Simple squamous epithelium ii Simple cuboidal epithelium iii Simple columnar epithelium iv Pseudostratified epithelium pseudo false D Stratified epithelial tissue i Stratified squamous epithelium ii Stratified cuboidal epithelium iii Stratified columnar epithelium iv Transitional epithelium V Glandular epithelial tissue A Exocrine i tubular vs alveolar ii branched vs unbranched iii simple vs compound simple duct does not branch compound duct branches B Endocrine