A lot vs. Alot: 9 Grammatical Pitfalls
renal pelvis n.
A hollow flattened funnel-shaped expansion of the upper end of the ureter into which urine is discharged before entering the ureter.
enlarged upper end of the ureter, the tube through which urine flows from the kidney to the urinary bladder. The pelvis, which is shaped somewhat like a funnel that is curved to one side, is almost completely enclosed in the deep indentation on the concave side of the kidney, the sinus. The large end of the pelvis has roughly cuplike extensions, called calyces, within the kidney-these are cavities in which urine collects before it flows on into the urinary bladder.