abdomen anus appendix belly blind gut bottomless pit brain cecum colon core deep space deeps depths duodenum endocardium entrails foregut gaping depths giblets gizzard gut guts heart hell hindgut infernal pit innards inner mechanism insides interior internals intestine intestines inwards jejunum kidney kishkes large intestine liver liver and lights lung midgut nether world outer space perineum pump pylorus rectum small intestine spleen stomach ticker tripes underworld unfathomed deeps unknown depths vermiform appendix viscera vitals works