《黄帝内经·素问·阴阳别论》
五时各有五脏的阳脉，所以五时配合五脏，则为二十五种阳脉。
所谓阴者，真脏也。见则为败，败必死也。
The five yang-channels are determined by the five movements, so the five movements correspond to the five zangs, which equals twenty five yang-channels.