CartilageandBone1.Cartilage:organ=Cartilagetissue+perichondrium1)structureofcartilagetissue---cell:chondrocyte---cartilagematrix①chondrocyte:---Structure:LMembeddedincartilagelacunaperipheralcells:--smallandimmature--singleandflattenedcentralcell:--largeandmature,--roundandingroupof2-8cells--smallandroundnucleus--basophiliccytoplasm--EM:richinRERandGolgicomplex*isogenousgroup:severalcellslocatesinonelacuna,whicharederivedfromasingle(same)parentcell②Cartilagematrix---groundsubstance:proteoglycan:--sametolooseCT--therearemorechondroitinsulfatedistributedattheperipheryofcartilagelacuna---calledascartilagecapsule(basophilic)water---fiber:typeandnumberoffiberdependsonthetypeofcartilage2)Classification:accordingtothefibera.Hyalinecartilage:lesscollagenousfibrilarticularsurface,ribcartilage,tracheaandbronchib.Fibrouscartilage:largeamountofcollagenousfiberbundlescellsaresmallandlessintervertebraldisc,symphysispubisc.Elasticcartilage:largeamountofelasticfiberexternalear,epiglottis3)perichondriumtwolayers:---outlayer:containmorefiber-protection---innerlayer:morecells-osteoprogenitorcell(fusiforminshape)4)growthofcartilage---interstitialgrowth:innerchondrocyteproliferation→producefiberandmatrix.immaturecartilage---appositionalgrowth:osteoprogenitorcell→chondroblast→chondrocyte→producefiberandmatrix.growingandmaturecartilage2.Bone---consistsofbonetissue,periosteumandendosteum,bonemarrow1)Bonetissue①Cells:a.osteoprogenitorcell:stemcell---structure:fusiform,smallovoidnucleusslightbasophiliccytoplasmexistinperiosteumandendosteum---function:differentiatedintoosteoblastandchondrocyteb.osteoblast:---structure:LM:singlelayerofcuboidalorlowcolumnarcellroundnucleusbasophiliccytoplasmlocatedonthesurfaceofbonetissueEM:fineprocessesrichinRER,Golgicomplex---function:ⅰ.synthesizebonecollagenfiberandgroundsubstance-osteoidⅱ.releasematrixvesicle:0.1umindiametermembrane-coatedfunction:promotecalcificationc.osteocyte---structure:flattenedcellwithmultiplelongthinprocesseslocatedinbonelacunaandbonecanaliculusbasophiliccytoplasmadjacentcellsconnectinbonecanaliculusbygapjunctions---function:Maintainbonematrixd.osteoclast---structure:LM:multinuclearlargecell,30-100um6-50nucleiacidophiliccytoplasmlocatedatperipheralpartofboneEM:ruffledborder-processeslightzone:--undertheruffledborder--microfilamentprimarylysosome,pinosomeandsecondarylysosomeRER,mito.andGolgi---function:dissolveandabsorbbonematrix②Bonematrix---organicmatter:bonecollagenfiber-collagenousfiber(typeIcollagen)groundsubstance:glycosaminoglycan---inorganicmatter:bonesaltsHydroxyapatitecrystal:Ca10(PO4)6(OH)2pin-shapedlongitudinalarranged*bonelamella:bonematrixarrangedinlayersatdifferentdirection2)ArchitactureoflongboneLongboneisanorgan,madeupofbonetissue(shaftandepiphyses),periosteumandendosteum,bonemarrow①shaft:consistsofcompactbonea.circumferentiallamella:/outerconcentrically-arranged/inneraroundinnersurfaceofboneb.Haversiansystem(osteon):/cylindricstructure,3-5mm/centralcanal:N,BV,CT/Haversianlamella:4-20layersc.interstitiallamella:/irregularlamella/remnantofHaversianorcircumferentiallamella*perforatingcanal:/transversecanal/connectwithHaversiancanal②epiphyses:composedofspongybone---trabeculae:formedbyparallelly-arrangedlamellaformaspongy-likednetwork---Bonemarrow:hemopoietictissue③periosteumandendosteum:CTmembrane---periosteum:DCTouterlayer:morefiberbundlesformperforatingfiberinnerlayer:richinBV,Nandosteoprogenitorcells---endosteum:thin,alayerofosteoprogenitorcellandCT---function:providenutritionandosteoblastforbonegrowthandrepairing3)osteogenesisSelfstudy!
