所属栏目:组织学与胚胎学
Epithelialtissuesarecomposedofcloselyaggregatedpolyhedralcellswithverylittleextracellularsubstance.Animportantfeatureofepitheliaistheirpolarity:theyhaveafreesurfaceandabasalsurfacethatrestonthebasalmembrane.Sincebloodvesselsdonotnormallypenetrateanepithel ......(本文共 1229 字 ) [阅读本文] >>