abnormal juxtaglomerular apparatus morphology abnormal distal convoluted tubule morphology abnormal macula densa morphology 2011-10-11T04:01:54Z MP:0011299 MPheno.ontology any structural anomaly of the specialized group of densely packed epithelial cells marking the origin of the convoluted portion of the distal tubule of a nephron, in contact with the afferent arteriole of the renal corpuscle and contiguous with the juxtaglomerular cells; these cells are tall, thin and columnar, have prominent nuclei, and act as sensors of solute concentration and flow of tubular fluid csmith