What does the pelvis of the kidney refer to?

The pelvis of the kidney is referred to as the area where urine is collected before it enters the ureter. This structure is essentially a funnel-shaped cavity located within the kidney, forming part of the renal collecting system. Once urine is produced in the nephrons of the kidneys through a filtering process, it drains into the renal pelvis. From there, the urine is directed into the ureter, which transports it to the bladder for storage.

This anatomical feature plays a crucial role in the overall urinary system, serving as a conduit for urine and ensuring that it moves efficiently from the kidney to the ureter. Therefore, understanding the function of the renal pelvis is essential for grasping how the kidneys contribute to the excretion of waste and regulation of bodily fluids. Other components noted in the answer choices, like the outer region, filtering system, and hormone production, refer to different aspects of kidney anatomy and function, but they do not accurately describe the specific purpose of the pelvis of the kidney.