1 wooden board, 1 glass jar (acts as kidney), 3 plastic pipes (acts as renal pelvis, renal vein and renal artery), thread for attaching the pipes with the board, a small container placed at the bottom acts as urinary bladder, a siphon pump at the back of the board inserted into a jar (acts as heart).
At the first glass jar (kidney) is placed on the top of the wooden board and cotton balls are packed inside the glass jar, and three holes are made below the jar, and one end of each of the three plastic pipes are placed properly into the holes.The two other ends of pipe go to jar fitted with siphon pump (heart). One pipe is called renal artery that take blood from heart towards kidney, another pipe is known as renal vein that carries out blood from kidney and transport it to heart.Third pipe (renal pelvis) from glass jar (kidney) meets with the urethra present in the urinary bladder (small container at the bottom). The holes present in cotton will allow the water to flow out and will eventually collected by renal pelvis and transported to the urinary bladder by ureter.
This in short is the working model of kidney.