（长三丈二尺，左回叠积十六曲。胃之下口，小肠上口也，在脐上二寸，水谷于是入焉。再
下一寸水分穴，则小肠下口也，至是泌别清浊，水液入膀胱，滓秽入大肠）《灵枢》曰∶手太阳之脉，走于小
指之端（少泽穴也），循手外侧（小指本节前谷穴也，本节后陷中后溪穴也），上腕（臂下、掌上节处曰腕。
腕前起骨下陷中腕骨穴也，当腕中陷处，阳谷穴之次），出踝中，直上循臂骨下廉，出肘内侧两筋之间（循臂
骨下廉阳谷等穴，出肘内侧两骨尖陷中小海穴。此处捺之，应于小指之上），上循 外后廉（行手阳明、少阳
之外），出肩解，绕肩胛，交肩上（肩后骨缝曰肩解，即肩贞穴。肩胛，即 俞、天宗等处也。肩上，秉风、
曲垣等穴也。左右交于两肩之上，会于督脉之大椎。滑氏曰∶脊两旁曰膂，膂上两角曰肩解，肩解下成片骨
曰肩胛，即肩膊也），入缺盆，络心（自缺盆由胸下行，入膻中，络心，心与小肠为表里也），循咽，下膈，
抵胃，属小肠（自缺盆之下，循咽下膈，抵胃，下行当脐上二寸之分，属小肠，此行于内者）；其支者，从缺
盆循颈上颊，至目锐 ，却入耳中（其支行于外者，出缺盆，循颈中之天窗，上颊后之天容，由颧 以入耳中
听宫穴也，手太阳经止于此）；其支者，别颊，上 ，抵鼻，至目内 ，斜络于颧（目下为 。目内角为内 。
颧，即颧骨下颧 穴，手太阳自此交目内 ，而接乎足太阳经）。其别，名曰支正，上腕、五寸，内注少阴；
其别者，上走肘，络肩 。其正指地，别于肩解，入腋走心，系小肠。其筋起于小指之上，结于腕，上循臂内
廉，结于肘内锐骨之后，弹之应小指之上，入结于腋下（手小指上外侧，少泽穴也，上行结于手腕外侧腕骨、
阳谷之次，上循臂内侧，结于肘下锐骨之后小海之次，但于肘尖下两骨罅中，以指捺其筋，则酸麻应于小指之
上是验，又由肘上 外廉，入结于后腋之下，皆刚筋也）；其支者，复走腋后廉，上绕肩胛，循颈出走太阳
之前，结于耳后完骨（其支者，自腋下与足太阳之筋合，走腋后廉，上绕肩胛，行肩外俞、肩中俞，循颈中天
窗之分，出走太阳经筋，自缺盆出者之前，同上结于耳后完骨之次）；其支者，入耳中；直者，出耳上，下结
于颔，上属目外 （此支者，自颈上曲牙，入耳中听宫之分；其直者，上行至耳上，会于手少阳角孙之分；其
前而下者，循颐，结于颔，与手阳明经筋合；其前而上者，属目外 ，瞳子 之次，与手足少阳之筋合也）。
是动则病嗌痛颔肿，不可回顾，肩似拔， 似折。是主液所生病者，耳聋，目黄，颊肿，颈颔肩 肘臂外后廉
痛。盛者人迎大再倍于寸口，虚者人迎反小于寸口也。
The small intestine is three zhang and two chi in length, coiling to the left with sixteen folds. The lower opening of the stomach is the upper opening of the small intestine, located two cun above the umbilicus, where water and food enter. One cun below this is the Shuifen (Water Division) acupoint, which marks the lower opening of the small intestine. Here, the small intestine separates the clear from the turbid: liquid fluids enter the Bladder, while waste matter enters the Large Intestine.
The *Ling Shu* states: The Hand-Taiyang [Small Intestine] meridian travels to the tip of the little finger (Shaose, SI 1), follows the ulnar side of the hand (Qian Gu, SI 2 before the proximal interphalangeal joint; Hou Xi, SI 3 after it), ascends to the wrist (the junction of the lower arm and palm is called the wrist. Wangu, SI 4 is in the depression below the raised bone at the front of the wrist, situated in the central depression of the wrist, next to Yanggu, SI 5), exits the malleolus, goes straight up along the medial border of the forearm bone, emerges between the two tendons on the medial side of the elbow (following the medial border of the forearm bone past Yanggu, etc., emerging into the depression between the two bony prominences on the medial side of the elbow, Xiaohai, SI 8. Pressing here elicits a sensation in the little finger), ascends along the posterior lateral border of the upper arm (running outside the Hand-Yangming and Hand-Shaoyang meridians), emerges from the shoulder joint (the bony cleft behind the shoulder is called Jianjie, corresponding to Jianzhen, SI 9. The scapula includes areas such as Tianliao and Tianzong. The shoulder region includes Bingfeng and Qu Yuan. The left and right meridians intersect above both shoulders and converge at Dazhui, GV 14 of the Du vessel. Mr. Hua noted: The sides of the spine are called Lü; the two angles above Lü are called Jianjie; the flat bone below Jianjie is the scapula, i.e., the shoulder blade), enters the Supraclavicular Fossa (Quepen), and connects with the Heart (descending from Quepen through the chest into Danzhong, connecting with the Heart; the Heart and Small Intestine are interior-exteriorly related), follows the pharynx, passes through the diaphragm, reaches the Stomach, and belongs to the Small Intestine (from below Quepen, following the pharynx through the diaphragm to the Stomach, descending to the area two cun above the umbilicus, belonging to the Small Intestine; this is the internal course); its branch, from Quepen, follows the neck up to the cheek, reaches the outer canthus of the eye, then re-enters the ear (this branch runs externally, exiting Quepen, following Tianchuang in the neck, ascending to Tianrong behind the cheek, entering the Ear-Auditory Palace [Tinggong, SI 19] via the zygomatic arch, where the Hand-Taiyang meridian ends); another branch diverges from the cheek, ascends to the infraorbital region, reaches the nose, arrives at the inner canthus of the eye, and obliquely connects with the zygoma (the area below the eye is the zygoma. The inner corner of the eye is the inner canthus. Zygoma refers to the Qiangliao acupoint below the zygomatic bone; the Hand-Taiyang meridian intersects here at the inner canthus, connecting with the Foot-Taiyang meridian). Its collateral is named Zhizheng, ascends five cun above the wrist, and internally injects into the Hand-Shaoyin [Heart] meridian; its other collateral ascends to the elbow and connects with Jianzhen. The main trunk descends vertically, diverges at Jianjie, enters the axilla, travels to the Heart, and ties to the Small Intestine.
The Hand-Taiyang sinew system originates above the little finger, knots at the wrist, ascends along the medial border of the forearm, knots behind the sharp bone inside the elbow, and when flicked, the sensation responds above the little finger; it enters and knots in the axilla (on the lateral aspect of the little finger is Shaose, SI 1; ascending, it knots at the lateral wrist near Wangu, SI 4, and Yanggu, SI 5; ascending along the medial forearm, it knots near Xiaohai, SI 8, behind the sharp bone below the elbow. If one presses the tendon in the gap between the two bones below the elbow tip, the numbness responding in the little finger confirms this. It then ascends along the posterior lateral border of the upper arm and enters to knot below the posterior axilla; these are all rigid sinews); its branch again travels along the posterior border of the axilla, ascends around the scapula, follows the neck, and emerges anterior to the Foot-Taiyang sinew system, knotting at Wan Gu behind the ear (its branch merges with the Foot-Taiyang sinew system from the axilla, travels along the posterior axillary border, ascends around the scapula, passing through Jianwaishu and Jianzhongshu, follows Tianchuang in the neck, emerges anterior to the Foot-Taiyang sinew system originating from Quepen, and converges above at Wan Gu); its branch enters the ear; the straight portion emerges above the ear, descends to knot at the mandible, and ascends to belong to the outer canthus of the eye (this branch ascends from the neck to Quya, entering Tinggong in the ear; the straight portion ascends to above the ear, meeting the Jiaosun point of the Hand-Shaoyang meridian; the branch that moves forward and downward follows the chin, knots at the mandible, and merges with the Hand-Yangming sinew system; the branch that moves forward and upward belongs to the outer canthus, next to Tongziliao, merging with the sinew systems of the Hand and Foot Shaoyang meridians).
When this meridian is disturbed, it causes pain in the throat and swelling of the mandible, inability to look back, a feeling as if the shoulder is being pulled out, and a feeling as if the elbow is broken. This meridian primarily governs diseases generated by fluids, such as deafness, yellow eyes, swollen cheeks, and pain along the posterior lateral border of the neck, mandible, shoulder, elbow, and arm. In excess conditions, the Renying pulse is twice as large as the Cunkou pulse; in deficiency conditions, the Renying pulse is smaller than the Cunkou pulse.