This chapter list the steps involved in preparing animal tissue for microscopic viewing; list several structural and functional characteristics of epithelial tissue; name, classify, and describe the various types of epithelia, and indicate their chief function(s) and location(s). | 4 Tissue: The Living Fabric: Part A Tissues Groups of cells similar in structure and function Types of tissues Epithelial tissue Connective tissue Muscle tissue Nerve tissue Figure Nervous tissue: Internal communication • Brain, spinal cord, and nerves Muscle tissue: Contracts to cause movement • Muscles attached to bones (skeletal) • Muscles of heart (cardiac) • Muscles of walls of hollow organs (smooth) Epithelial tissue: Forms boundaries between different environments, protects, secretes, absorbs, filters • Skin surface (epidermis) • Lining of GI tract organs and other hollow organs Connective tissue: Supports, protects, binds other tissues together • Bones • Tendons • Fat and other soft padding tissue Epithelial Tissue (Epithelium) Two main types (by location): Covering and lining epithelia On external and internal surfaces Glandular epithelia Secretory tissue in glands Characteristics of Epithelial Tissue Cells have polarity—apical (upper, free) and basal (lower, attached) surfaces Apical surfaces may bear microvilli (., brush border of intestinal lining) or cilia (., lining of trachea) Noncellular basal lamina of glycoprotein and collagen lies adjacent to basal surface Characteristics of Epithelial Tissue Are composed of closely packed cells Continuous sheets held together by tight junctions and desmosomes Supported by a connective tissue reticular lamina (under the basal lamina) Avascular but innervated High rate of regeneration Classification of Epithelia Ask two questions: How many layers? 1 = simple epithelium >1 = stratified epithelium Figure Stratified Simple Apical surface Basal surface Apical surface Basal surface (a) Classification based on number of cell layers. Classification of Epithelia What type of cell? Squamous Cuboidal Columnar (If stratified, name according to apical layer of cells) Figure Squamous Cuboidal Columnar (b) Classification based on cell shape. Overview of Epithelial Tissues For each of the following types of . | 4 Tissue: The Living Fabric: Part A Tissues Groups of cells similar in structure and function Types of tissues Epithelial tissue Connective tissue Muscle tissue Nerve tissue Figure Nervous tissue: Internal communication • Brain, spinal cord, and nerves Muscle tissue: Contracts to cause movement • Muscles attached to bones (skeletal) • Muscles of heart (cardiac) • Muscles of walls of hollow organs (smooth) Epithelial tissue: Forms boundaries between different environments, protects, secretes, absorbs, filters • Skin surface (epidermis) • Lining of GI tract organs and other hollow organs Connective tissue: Supports, protects, binds other tissues together • Bones • Tendons • Fat and other soft padding tissue Epithelial Tissue (Epithelium) Two main types (by location): Covering and lining epithelia On external and internal surfaces Glandular epithelia Secretory tissue in glands Characteristics of Epithelial Tissue Cells have polarity—apical (upper, free) and basal (lower, attached) .
