abnormal juxtaglomerular apparatus morphology abnormal juxtaglomerular cell morphology 2011-10-11T04:05:39Z MP:0011300 MPheno.ontology abnormal (renal) granular cell morphology abnormal J-G cell morphology any structural anomaly of the specialized smooth muscle cells that synthesize, store, and secrete renin and are found in the wall of each afferent arteriole of a kidney glomerulus near its point of entry adjacent to a macula densa; J-G cells are distinguished by their granulated cytoplasm and play a critical role in the renin-angiotensin system and thus in renal autoregulation csmith