Woodcut from Shoushi neijing tushuo (Pictorial Guide to the Internal Mirror of Longevity), a text ascribed to the much-revered physician Bianque, who lived around 500 BCE. This edition was published in 1693 (32nd year of the Kangxi reign period of the Qing dynasty). This image illustrates the relationship between the heart channel of hand shaoyin and the small intestine channel of hand taiyang, i.e. the heart is situated above the diaphragm and the small intestine below it; and the heart and small intestine are linked by a network of channels and tributaries, setting up an exterior-interior relationship.
