1.Mucosab.Laminapropriaalayerof connectivetissue,containing:glandsbloodandlymphaticvessels--transporting digestedproducts·glands-- secreting mucin or enzyme, etclymphoidtissue--asanimmunologicbarrier--produceantibodies (lgA)lymphoid11tissue
11 1. Mucosa b. Lamina propria v a layer of connective tissue, containing: blood and lymphatic vessels - transporting digested products glands - secreting mucin or enzyme, etc. lymphoid tissue - as an immunologic barrier. - produce antibodies (IgA) glands lymphoid tissue
Thelymphoidtissueperformsvarious immunologicalfunctionsThe laminapropria, located justbelowthe epithelium,is a zonerich in macrophages and lymphoid cells, some of which activelyproduceantibodies.These antibodies aremainlyimmunoglobulinA (IgA)and arebound toa secretoryprotein produced bythe epithelial cellsofthe intestinal lining and secreted into the intestinal lumen.Thiscomplexprotectsagainstviralandbacterial invasion.The SlgApresent inthe respiratory,digestive,and urinarytractsisresistanttoproteolyticenzymesand cantherefore coexistwith theproteasespresent in thelumen.12
12 The lymphoid tissue performs various immunological functions v The lamina propria, located just below the epithelium, is a zone rich in macrophages and lymphoid cells, some of which actively produce antibodies. v These antibodies are mainly immunoglobulin A (IgA) and are bound to a secretory protein produced by the epithelial cells of the intestinal lining and secreted into the intestinal lumen. This complex protects against viral and bacterial invasion. v The SIgA present in the respiratory, digestive, and urinary tracts is resistant to proteolytic enzymes and can therefore coexist with the proteases present in the lumen
1.Mucosac.MuscularismucosaItconsistsofsmoothmuscles文separating mucosa fromsubmucosaathinlayerof smoothmuscle cellsortwothinlayers:aninnercircularandanouterlongitudinal layersItscontractionassistssecretionofminorglandsandabsorptionofnutrients
13 1. Mucosa c. Muscularis mucosa v It consists of smooth muscles separating mucosa from submucosa - a thin layer of smooth muscle cells or - two thin layers: an inner circular and an outer longitudinal layers v Its contraction assists secretion of minor glands and absorption of nutrients c
2. Submucosaalayer of loose connective tissuecontaining:manyblood/lymphaticvessels glands: be found only in the esophagusandduodenumsubmucosalplexuslymphoidtissueglands
containing: u many blood / lymphatic vessels u glands: be found only in the esophagus and duodenum u submucosal plexus u lymphoid tissue 2. Submucosa a layer of loose connective tissue glands
2.Submucosamucosasubmucosa*plicamucosaandsubmucosaareoftenarranged in longitudinal or circular foldsesophagusprotrude into the lumen of the digestive tractinorderto increasethesurfacearea15
15 *plica u mucosa and submucosa are often arranged in longitudinal or circular folds protrude into the lumen of the digestive tract u in order to increase the surface area 2. Submucosa mucosa submucosa esophagus