renal calyx renal calyx the renal calyces are chambers of the kidney through which urine passes. the minor calyces surround the apex of the renal pyramids. urine formed in the kidney passes through a renal papilla at the apex into the minor calyx; two or three minor calyces converge to form a major calyx, through which urine passes before continuing through the renal pelvis into the ureter. renal calyxkidney, with major and minor calyces labeled near bottom.an image showing just the pelvis and calices of the kidneys, with the rest of the kidney removed, from a dissected cow and seal specimen. these vary greatly in size and number depending on species.detailsprecursorureteric budsystemurinary systemidentifierslatincalices renalesmeshd007670fma284558anatomical terminology function peristalsis of the smooth muscle originating in pace-maker cells originating in the walls of the calyces propels urine through the renal pelvis and ureters to the bladder. the initiation is caused by the increase in volume that stretches the walls of the calyces. this causes them to fire impulses which stimulate rhythmical contraction and relaxation, called peristalsis. parasympathetic innervation enhances the peristalsis while sympathetic innervation inhibits it. clinical significance example of a "staghorn" kidney stone projecting into the renal calyces a "staghorn calculus" is a kidney stone that may extend into the renal calyces. a renal diverticulum is diverticulum of renal calyces.