组织学与胚胎学Epithelial tissue.ppt

Chapter 2 Epithelial tissue Emphases of today’s lecture 1. Classification of epithelial tissue 2.Membrane specializations of epithelial cells Functions of Epithelium Simple epithelium Simple squamous E Simple cuboidal E Simple columnar E Pseudostratified ciliated columnar E · Stratified epithelium Stratified squamous epithelium Stratified cuboidal epithelium Stratified columnar epithelium Transitional epithelium Summary 1 Epithelium: covering epithelium and glands Classification of covering epithelium simple squamous stratified cuboidal columnar Summary 2 Glandular epithelium Today’s lecture Classification of Epithelium: distribution and function Membrane specialization of epithelial cell Glandular epithelium · Stratified squamous epithelium B A Typical location: Epidermis, oral cavity, esophagus, vagina Major function: Barrier, protection C · Stratified cuboidal epithelium Typical location: Large ducts of exocrine glands Major function: Barrier, conduit Typical location: Large ducts of exocrine glands, sweat gland duct Major function: Barrier, conduit · Stratified columnar epithelium · Transitional epithelium B A Typical location: Urinary tract (renal calyces, ureters, bladder, urethra) Major function: Barrier, distensible property Superficial cells Specialization of Epithelium 1. Modification of free surface Microvilli Stereocilia Cilia · Microvilli A B Microvilli are finger-like cytoplasmic projection on the free surface of most epithelial cells. Function: increase the surface areas Distribution: striated border: intestinal epi. cell brush border: proximal renal tubule Goblet cell · Stereocilia Stereocilia are usually long, immotile microvilli. Function: increase the cell surface area, facilitating the movement of molecules into and out of