Channel chart of the dorsal and spinal area, woodcut illustration from Cai ai bianyi (The Mugwort Gatherer's Companion), published in 1805 (10th year of the Jiaqing reign period of the Qing dynasty).
In this image, the paths of the channels of the back and spine are represented by lines on a schematic outline drawing. The central line corresponds to renmai (the Director Vessel, also translated as Conception Vessel); the four lines arranged in pairs on either side all correspond to the bladder channel of foot taiyang.
