Cell Tissues Epithelial Tissues

Tissues Group of cells with similar structure and function Main functions Covering (epithelial) Support (connective) Movement (muscle) Control (nervous)

Epithelial Tissue Lining, covering, and glandular tissues Functions Protection Absorption Filtration Secretion (glandular only)

Epithelial Tissue Characteristics Fit together in sheets (except glandular) Apical surface – free surface Basement membrane – structureless, rests on Avascular – no blood supply Regenerate easily

Epithelial Tissue Classification – 2 part naming system Cell arrangement/number of layers Simple – one layer Stratified – more than one layer Cell shape Squamous – flat Cuboidal – cube shaped Columnar – column shaped

Simple Epithelial Tissue Simple squamous Single layer, flat cells Form membranes where exchanges occur Found in lungs, capillaries, serous membranes Line ventral cavity and ducts

Simple Epithelial Cells Simple cuboidal Single layer, cube shaped Forms glands and ducts Simple columnar Single layer, tall cells Line digestive tract Often contain goblet cells (produce mucous)

Stratified Epithelial Cells Stratified squamous Most common epithelial cell Apical surface – squamous Basal layer – cuboidal/columnar Found in areas of frequent abuse Esophagus, mouth, outer skin

Stratified Epithelial Tissue Stratified Cuboidal Usually 2 layers, Surface is cuboidal Stratified Columnar - Basal cells vary Transitional Epithelial tissue Line organs in the urinary system (stretching) Cuboidal/columnar basal cells, Apical surface cells vary

Glandular Epithelial Tissue Secrete Two types Endocrine Ductless Diffuse products Exocrine Ducts Dump secretions on surface