During the 17th and 18th centuries when traditional Japanese physicians attempted to deduce the workings of the body from outward appearances in accordance with Asian traditional medical beliefs and practices, they used mannequins to explain to patients the effects of medicines.
This model depicts anatomy along the lines of a flow chart rather than a literal representation of different organs. "Hollow" (yang) organs were the gall bladder, stomach, large intestine, small intestine, bladder, and "triple burning or heating system" that regulated the flow of energy through the body. More "solid" (yin) organs were the heart, lung, liver, spleen, and kidney.
At the NMHM (National Museum of Health and Medicine) in Washington DC