kidney cortex morphology trait juxtaglomerular apparatus morphology trait juxtaglomerular complex morphology trait Trait.ontology Any measurable or observable characteristic related to the shape, structure, color, or pattern of the complex of modified smooth muscle cells consisting of juxtaglomerular cells, extraglomerular mesangium lacis cells, the macula densa of the distal convoluted tubule, and granular epithelial peripolar cells; these cells are found in the walls of afferent and efferent glomerular arterioles. VT:0002829