《黄帝内经·灵枢·经脉》
它的一条别行的支脉，在偏历穴处别行而出，然后就沿着手臂上行，经过肩髃穴所在的部位，再向上走行，而到达曲颊，进而斜行到牙根部并联络之。另一别出之脉，入耳中，而与耳部的宗脉会合。如本络脉发生病变，属实的，会出现龋齿、耳聋；属虚的，会出现牙齿发冷，膈间闭塞。治疗时，可取本经别出的偏历穴。
其别者，入耳，合于宗脉。实则龋聋，虚则齿寒痹隔。取之所别也。手少阳之别，名曰外关。
One of its separate branches diverges at the Pianli point and then runs up along the arm, passing the spot where the Jianyu point is and continuing upward to reach Qujia, after which it goes obliquely to the roots of the teeth to connect to them. Another separate branch enters the ear and joins the ear's zong pulse. If this branch pulse gets ill, a solid condition will cause decayed teeth and deafness, while a hollow condition will cause cold teeth and obstruction between the diaphragm. When treating, the Bianli point, which is this meridian's separate branch, can be used.