What structure collects urine from the kidneys?

The correct answer is that the renal pelvis is the structure that collects urine from the kidneys. The renal pelvis is a funnel-shaped cavity located in the center of each kidney. It serves as the primary conduit for urine, allowing it to flow from the collecting ducts within the kidneys into the ureters.

The renal pelvis acts as a collection point; once urine is formed in the renal nephron, it drains into the renal pelvis before being transported to the bladder via the ureters. This structure plays a crucial role in the urinary system by facilitating the proper flow of urine and preventing backflow through its muscular walls.

Understanding the function of the renal pelvis is essential since it also helps in diagnosing certain kidney conditions, such as hydronephrosis, where urine builds up due to an obstruction in the urinary tract.