Final answer:
The collecting duct is the part of the nephron located in both the renal cortex and renal medulla. It receives filtrate from many nephrons, helps finalize the concentration of urine, and merges into papillary ducts.
Step-by-step explanation:
The part of the nephron located both in the renal cortex and renal medulla that receives filtrate from many nephrons, helps finalize the concentration of urine, and merges into papillary ducts is the collecting duct. The collecting ducts amass contents from multiple nephrons and fuse together as they enter the papillae of the renal medulla.