The trigon of the bladder is formed by the two urethral slit openings and the urethral orifice, the trigon of the bladder. So basically, it is formed by two slit-like urethral orifices and the internal urethral opening. So if there is a bleeding from the ureter as seen on this patient's cystoscopy, suggests an origin of upper urinary tract problem. It is from the kidney or from the ureter. So in contrast, if there is a lower urinary tract bleeding, like a trauma or infection, it actually originates in the bladder or the urethral lesion as the source and typically directly visualized upon insertion of a cystoscope through the urethra into the bladder. So the etiology of upper urinary tract bleeding is often identified based on the signs and symptoms that you are in the question stem. So for example, such as flank pain, suggests of ureteric stone, as any of the symptoms associated with hypertension and proteinuria, then glomerular disease. If fever and pyuria is given, then pyelonephritis. In the absence of any of the above findings, then we should think of renal papillary necrosis should be considered as a cause of bleeding of the upper urinary tract and this condition is characterized by infarction of the renal medullary vessels leading to sloughing of renal papilla and gross hematuria. So what I want to say is the bladder trigon is formed by two slit-like urethral orifices and the internal urethral opening. Blood within the urethral orifices suggests an upper tract bleeding originating from the kidney. Rule out the possibilities using the symptoms in the stem. If not, in the absence of any of such findings, you have to put the answer as renal papillary necrosis. this concept i want as small sticky notes yiu can just write a text dont make visual sticky note HY NBME level topper note quick q solving