glomerular endothelium fenestra A large plasma membrane-lined circular pore that perforates the flattened glomerular endothelium and, unlike those of other fenestrated capillaries, is not spanned by diaphragms; the density and size of glomerular fenestrae account, at least in part, for the high permeability of the glomerular capillary wall to water and small solutes. glomerular endothelial cell fenestration GO:0036053 2011-12-12T10:53:24Z GEnC fenestration pore complex