\ r*l sfu\ crxtt*i ( 3 ) efui+..it 31si1P : t Typ*r of Epitfiefnfr Transi[onal Sinple squarrlus Sktpls cuboilal cruboidal ffiP*udssfatified cohrmnar Sfratified quamous Sraffied sxTRA Examples of spithelium: Types of simple epithelium: Squamous epithelium is a single layer of flat scale-shaped cells .simple squamous r:-l l:-:-- of ffiffiil6tt*tiai tining of blood vessels and the mesothelial lining Squamqus means scale-like .Lines small ducts, tubules function - i-e. in salivary It can have an excretory, secretory or absortive .glands F This image opposite is of ducts in the kidney, which are lined by simple cuboidal epithelium b .CoIumnar .This is a single of cells, md the cells are all tall columnar \ basfient neilbrurg ,/ This picture shows columnar cells from the stomach. A few of the cells are outliniad" to help you identifr them .Tatl columnar epithelium lines the ducts of many exocrine glands t7 This type of epithelium is adapted for secretion and/or absorption, and can also be protective Simple secretory columnar epithelium lines the stomach and uterine cervix.The simple columnar epithelium that lines the intestine also contains .a few goblet cells Tall u,, .* columnar nuclei al difierent lenlels . In histological slides ofpseudostratified epithelium, it looks as though some of the cells are not in contact with the basal lamina, and the nuclei are at different levels. So it looks as though there is more than one layer of .cells However EM shows that all the cells contact the basal lamina, so this is a 'simple' epithelium. But it is called pseudostratified, because of its .appearance Pseudostratified ciliated columnar epithelium containing goblet cells lines This is an example of pseudostratified epithelium, &om the jejunum. l8 I l-H&E stain of normal biopsy of esophagus showing sfiatified squ:Lmous cell epithelium. .2-Diagarn of the layers of the epithelial skin layer: the epiderrnis ffirn sflE fi Shchrm hrithnn Sndurn fgdo*lnr- ffinn ry*mqm Glandular Epithelium Tissues: Gland: A cell, a group of cells, or an organ that produces a secretion for use elsewhere in the body or in a body cavrty or for elirnination from the My. Types of glands: There are two main types of gland and they are: exorrine and endocrine glands. A: Exocrine glands: secrete substances into cavities or surfaces in the body, They secrete substances via a duc! with examples including the sweat glands, manrmary glands, salivary glands and glands located in the drgestive system. Categories of exocrine gland include: Classifrcations of exocrine glands: Exocrine classified according to:- l- Cells number. 2- The shape of glandular unit. 3- Types of duct ( simple or branching ) 19 a 4- Secretory portion and,clucts. 5- lvlethocjs rll' relcase secnetion- 6- IrJature of secreticln. I - Glands according to number of cells. a : Unicellular glands, E*p..Goblet cell irr tracheal epitirelium in mammals, t,,"::"-:::::ll:::llorein, rnucin, whicrr r,y tr,* uprake of water is converred lnt0 slinny su'bstances ,tnucus" MLr lticellular glancls : * glands composcrcl ol. many cells. o T'hey vary fronr sirnple tube such as intestinal glands to highly complex Consisting of glanclular portion of sec[eting alveoli ( or acini ) or tubr-rrar ( either straight, coiled or brarlrched) and a proxinra| excretory durct, as sarivary grand, Ail grand, ,ontuining loose connectivc tissues" * Compounds glantls itre slrrrounded by connective tissues that form capsule, ftorn the capsule connective trabeculai extend into gtand ciir,iding it into Iohules. 'i'he s glaildurar tir'rsur.) of'a grand is callerj parenchyma and Lronnectivc tissuc caIled stromae. 2.GIandsaccorc|ingtotlreshapeofgIandularunit. 'l'ile o secl'etory portion may have a variety of shapes. secretory cells rnav filrm: 'f a) urbes in tuhrular gllancls. b) Acini in acinau"gland. c) Alveoli in alveolar qland. -rr * tutndtr drres* "l-Accorcling to the'l'y,pes of'duct ( sirnple or branching ): *) Sinipir: glarids .tfre duct nclt branched. b) Compound glands the duct was branched. 4- According to the secretory pofiion and ducts. a) Simple tubular ( sweat glancr) and branched tuburag ( pyloric grand). Lr) Sirrlple acinar as thc (sub epitSelial glancls o{'esophagus ) and bran*hsd acinar Iike sebaceous glancl). c) f ubuloacinar, sinrple and branctred like some salivpv glands d) Compound acinar. e) L'ompound tubular. 5 -{l i and s auco rcl itrg to nlethotls of' rel eased secretclry proijuct: a) Mcrtlcrllle ;;;tuil secretion) . the product is released by a process of exocytosis without rhe loss of any glandular cytopfasm.( pancreas & salivary gland). l b) Apocl'iue secretion";jJill In whlch part oi apical cytoplasm ofthe cells is Iost together rvittr secretary procluct. ( sweat glands , mammary gianris , prostate. c) F{o}ocritre secretion ;;ril|. brea}ibown and.$ischarge entire secretary cell.it is only in setrarccous glancl of the skin. * ,- fucretory prc{uc$ rn lumenol gtarud Pincfied portiorp off A d&nntegrattrg of cells rebasing cell releasing secr€lory prodlrct lntact cell its cofttents A vesicle Ceflwith rete;rslng secretory rts contenls product New ce*e formforg Merocrm* glanci Apocrine gfrand 6- Glands according to the Nature of secretion: a) ser:ous secretory grands : these glands secrete watFry fluids rich in protein" b) MucoLtsi secretory glands: these glands secrete thiqk fluids rich in carbohydrate. c) Fatty secretory glands i : As Sebaceous glands: theqe glands secrete lipici substances. d t h,t Hil()stlr{)us sccrr)t{_}rv glands: as submandibular and sublingual g.liinds. e) Watery secretory glands : as sweat glands. f) waxy secretory grands: as glancrs of externar ear. Cellrrliir ii) secretory grands : as in testis and ovarv. Ii : $lrntlele rime glamds sccrete substances'directly and do not use ducts. gtancts inclucle rhe rhyroid gland, piruitary l:l:::,ll:: ']l*'l.t,rcrine ' gland, hypothalamus and the parathyroid gland.. i ' glands: plctryrine secrete substantes straight into the bioodstream. r. !Kc rtr)rntones. {'' : h4ixeci illands . whit:h p(}iissss the exocrine and endocrine functions |}''}}}ilr'uii5,tcstisitrudrlr,itrl,,,,,,. as 4- Neuro-Epitfrelium tissues i Neuro-llpithelium: It is the fourth epithelial tissue ( simpte , stratified, {iiandLrXar and Neu no-Epithelium " In this flrprr thc';pit!icli;*i ualls act as sensory receptors for special stirnuli. '1'hc n*iri"ti-*;:irlielia! {-:dlirq nrr providecl wir}i small hairs on ih.i, free ivhile ends, tlri:ir tra:les are surroundecj with sensory n.ru.r- i * 'f- - t. epithelium made up of cells speciali?rdto serve is sensory cells for reception of external stimuli. L 2. the ectodermal epitheliunq from which the central nervous system is derived. Neuro-epithelium \ ord csrfry tar& pflt + Taste bud Gnrm Seruods newpmr* $ryporeqocfi Crista ampulltris (ampullary cre$t) section t ),7.