Crescent are derived from which of the following

Refer Robbins page no Pg 921dahe glomeruli are large and hypercellular. The hypercellu- larity is produced both by proliferation of cells in the mesangium and so-called endocapillary proliferation involving capillary endothelium and infiltrating leukocytes. The glomeruli have an accentuated "lobular" appearance due to the proliferating mesangial cells and increased mesangial matrix (Fig. 20-16). The GBM is thickened, and often shows a "double- contour" or "tram-track" appearance, especially evident in silver or PAS stains. This is caused by "duplication" of the basement membrane (also commonly referred to as splitting), usually as the result of new basement membrane synthesis in response to subendothelial deposits of immune complexes. Between the duplicated basement membranes there is inclu- sion or interposition of cellular elements, which can be of mesangial, endothelial, or leukocytic origin. Such interposition also gives rise to the appearance of "split" basement mem- branes (Fig. 20-17A). Crescents are present in many cases