What are the receptacles surrounding renal papillae?

The receptacles surrounding renal papillae are known as minor calyces. These funnel-shaped structures collect urine produced in the renal tubules and transport it to the major calyces, which then lead to the renal pelvis. The minor calyces are located at the tips of the renal pyramids, where the renal papillae project, allowing urine to flow from the renal pyramids into the calyces.