(2)Classification(EM)Depending on the continuity of both the endothelial sheetand thebasal lamina,divided into3types:Continuous capillaryFenestratedcapillarySinusoidal capillary
(2) Classification (EM) Depending on the continuity of both the endothelial sheet and the basal lamina, divided into 3 types: Continuous capillary Fenestrated capillary Sinusoidal capillary
a. continuous capillary:ContinuouscapillaryBasementEndothelialcell membranejunctionuANucleusTrancytosisvesiclesEndothelialcellsbeneathbasementmembrane
a. continuous capillary:
tight junction*Endothelialprojections*Plasmalemmalvesicles:the pinocytotic vesiclesforlargemoleculetrans-cellmembranetransportation.transendothelialchannels*Enzymesystem
* tight junction * Endothelial projections * Plasmalemmal vesicles: the pinocytotic vesicles for large molecule transcell membrane transportation. transendothelial channels * Enzyme system
Weibel-Paladebody*Endotheliacontain specialtubular organelle,the Weibel-NPalade(WP)bodies, whichreleaseFactorVilll relatedantigen tofacilitatebloodclotting whenblood vesselsbreak.7* Distribution:muscle tissue,connective tissue
* Endothelia contain special tubular organelle, the WeibelPalade (WP) bodies, which release Factor VIII related antigen to facilitate blood clotting when blood vessels break. * Distribution: muscle tissue, connective tissue
b.fenestrated capillary:FenestratedcapillaryTrancytosis vesiclesuFenestrationsFenestratedorporesporesUDBasementEndothelialcellmembrane(cut)junctionBasementmembrane
b. fenestrated capillary: