Extraglomerular mesangial cells are part of the juxtaglomerular apparatus, along with the macula densa cells of the distal convoluted tubule and the juxtaglomerular cells of the afferent arteriole.
Among the elements that make up the juxtaglomerular apparatus are extraglomerular mesangial cells, macula densa cells from the distal convoluted tubule, and juxtaglomerular cells from the afferent arteriole.