'x' transports urine from kidney to the urinary bladder and 'y' transports urine from the urinary bladder to outside.
x - ureter, y - urethra
The ureter transports urine from kidney to the urinary bladder and urethra transports urine from the urinary bladder to outside. Blood reaches the kidney through renal artery and the filtered blood is pumped back through renal vein.