PATHOLOGY

Detailed explanation-1: -One-dimensional, lubrication-theory analysis shows that peristalsis can pump urine from kidney into the bladder only at relatively low mean rates of urine flow. Under these circumstances isolated boluses of urine are propelled steadily through the ureter (assumed uniform) by the contraction waves.

Detailed explanation-2: -Ureteral peristalsis is the process by which urine is propelled from the kidney to the bladder, and is generated secondary to contraction of the smooth muscles in the wall of the ureter (1).

Detailed explanation-3: -As the urine is collected in the renal pelvis, the pelvic pressure increases and initiates a peristaltic contraction that is propagated along the ureter to the bladder. The peristaltic wave can move urine against an obstacle, with a pressure of up to 50–100 mm Hg.