We went to the Vermont State Fair and in several pavilions that had cows, rabbits, and other wild life. We espied several digestive system diagrams - some drawn by children.
This poster had the definition of a cow. In summary it says:
In brief the externally visible features are: two lookers, two hookers,
four stand uppers, four hanger-downers and a swishey-wishey.
This one was of a cow (the fine print is hard to read).
This of course suggested the well-known cow's stomach diagram drawn by Bernie Greenberg to illustrate a new page control locking system for Multics (drawn in 1976).