Final answer:
The wide base of a renal pyramid is adjacent to the renal cortex, not the renal pelvis. The renal pyramids are located in the renal medulla and serve as the location where urine collects before moving towards the renal pelvis.
Step-by-step explanation:
The wide base of a renal pyramid lies next to the renal cortex. The renal pyramids are conical structures found within the renal medulla, and their bases are adjacent to the renal cortex. The renal pelvis, which is located in the region called the hilum of the kidney, is the area where the calyces join the ureters. However, it does not lie directly next to the base of the renal pyramid.
The renal cortex is the outer part of the kidney, containing all of the nephrons, some of which have loops of Henle extending into the medulla. The nephrons are the functional units of the kidney, and these are crucial for filtering blood and generating urine.