The Renal Pelvis and Calyces

Publisher Summary This chapter discusses the functionality of renal pelvis and calyces. The renal pelvis and calyces are embedded in the fatty tissue of the sinus renalis. They conduct urine to the upper ureter. The degree to which the conduit function of the calyces and pelvis is active or passive is incompletely understood. The observable contractile activity of both structures and the low-grade pressure fluctuations often detected in the pelvis speak for an active function. The structural organization of the funnel-shaped pelvis varies somewhat among mammals, being an intrarenal structure in the dog. In humans, some pelvises are extrarenal and may expand freely, while others are intrarenal. The relationship of calyceal contraction to pelvic contraction is variable. Calyceal emptying may occur simultaneously with pelvic emptying, independent of pelvic emptying, or in coordination with pelvic emptying.