Which structure delivers urine to a minor calyx?

The structure that delivers urine to a minor calyx is the papillary duct. The papillary ducts, also known as the ducts of Bellini, are located at the tips of the renal pyramids within the kidney. They receive urine from the collecting ducts and drain it directly into the minor calyces, which are small, cup-like structures that collect urine prior to its flow into the major calyces and subsequently to the renal pelvis.

In this context, the collecting duct does play a role in urine production, but its primary function is to collect urine from multiple nephrons and transport it to the papillary duct rather than directly to the minor calyx. The ureter is responsible for transporting urine from the kidney to the bladder, while the Loop of Henle is involved in the concentration of urine within the nephron, but does not participate in the delivery of urine to the calyces. Thus, the papillary duct is the correct structure that conveys urine to the minor calyx.