How does urine travel from collecting tubules to the renal pelvis?

In the human renal system, urine travels from the collecting tubules to the renal pelvis through a structured series of collecting cavities. The process follows this path:

• Collecting Tubules to Papillae: Urine produced in the nephrons flows into the final collecting tubules, which open onto the renal papilla of each renal pyramid.12
• Minor Calyxes: The urine exits the papillae and enters the minor calyxes, which are small, cuplike cavities that collect the fluid.123
• Major Calyxes: The minor calyxes drain into two or three larger cavities known as major calyxes.12
• Renal Pelvis: Finally, the major calyxes open into the renal pelvis, a funnel-shaped expansion that serves as the initial reservoir before the urine moves into the ureter.412

This movement is facilitated by peristaltic movements—rhythmic waves of muscle contraction—that begin in the minor calyxes and help propel the urine toward the bladder.41