What typically occurs when urine flow is blocked?

When urine flow is blocked, one of the physiological responses is the dilation of urine structures that are proximal to the obstruction. This occurs due to the buildup of urine that cannot be expelled from the bladder. As urine accumulates, pressure increases in the renal pelvis and ureters, leading to their swelling and dilation. This is a compensatory mechanism as the body attempts to deal with the obstruction.

The dilation can affect kidney function over time if the obstruction persists, potentially leading to additional complications such as hydronephrosis. Understanding this process is crucial for recognizing and managing conditions that lead to urinary obstruction.