Clockwork Heart

Little known fact: the human heart, pictured here in a model by JK Brickworks, has at least 16 gears, a choo choo mechanism and in some cases an escapement. This is all kept running by a small reactor located in the lower abdomen and lubricated by Bio Lubrication OOzing Dilution, or B.L.O.O.D. This explains the age old tradition of giving a heart shaped box full of mechanical parts (later changed to chocolate) to loved ones.