Channel chart: yinqiao mai (Yin Heel Vessel), Chinese woodcut

Woodcut illustration, showing the path of yinqiao mai (Yin Heel Vessel), from Jingmai tu kao (Illustrated Study of the Channels), published in 1878 (4th year of the Guangxu period of the Qing dynasty). Yinqiao mai is one of the Eight Extraordinary Channels (qi jing ba mai). It originates at the zhaohai (Shining Sea) point, at the back of the navicular bone of the foot (rangu), traverses the inner ankle, and runs upwards along the inside of the lower limbs into the genital area. It ascends within the thoracic cavity to the supraclavicular fossa (quepen, the Broken Basin), then ascends again to emerge in front of the renying (Human Welcome) point alongside the Adam's Apple. It passes through the cheeks into the eye sockets where it joins the taiyang channel and Yangqiao mai (Yang Heel Vessel). Pathological changes in this channel are thought to cause somnolence (shishui).

Picture title: Chart showing the path of yinqiao mai (Yin Heel Vessel). Other lettering: It starts behind rangu (the navicular bone of the foot), runs up the inner ankle, goes straight up to the groin, enters the genitalia, ascends inside the chest, enters the clavicular fossa (quepen, the Broken Basin), travels up to the Adam's Apple, intersects with chongmai (Penetrating vessel), ascends to emerge in front of renying (Human Welcome), joins at the inner canthus of the eye.