目的　对人腹外斜肌的神经入肌点定位和肌内神经染色观察，为其临床应用提供形态学资料。  方法　成尸11具定位神经入肌点和5具行Sihler’s 肌内神经染色。  结果　腹外斜肌受下8对肋间神经外侧肌支支配，各个肌齿的神经入肌点距离相应肌齿起端中点(1.54±0.33)cm，位于锁骨中线与第5肋下缘的交界处至腋后线与第11肋下缘交界处的连线上。Sihler’s染色显示支配腹外斜肌的肋间神经外侧肌支入肌后分出小分支分布到各肌齿的起端1/3，然后约在各肌齿的近、中1/3交界处分出2支二级神经分支，即上支与下支，它们分出小分支分布到各肌齿的中间1/3，相邻两个肌齿的上支与下支在各肌齿中远部形成“U”形吻合，从“U”形吻合弓上分出小分支分布到各肌齿的止端1/3。在腹外斜肌上半部，各肌齿的神经分支分布到相应的肌齿，但在腹外斜肌下半部，上一肌齿的远侧下份是由下一肌齿的神经分支(上支)分布。  结论　①为临床上腹壁局部麻醉和术后切口疼痛的神经阻滞提供指导意义；②腹外斜肌中远部从上至下形成“波浪形”的神经分支密集区；③腹部手术切口建议不要超过四个肌齿。

Objective　To locate the nerve entry points to human obliquus externus abdominis and to observe the intramuscular nerve staining to provide morphological data for clinical application.　Methods　The nerve entry points to the muscles were located in 11 adult cadavers and Sihler’s staining technique was applied in  5 adult cadavers.    Results    The obliquus externus abdominis was innervated by the lateral muscular branches of the inferior 8 pairs of intercostal nerves. The nerve entry point to each extended muscle fiber was (1.54 ± 0.33) cm from the midpoint at where the corresponding fiber arose, and was located at the connecting line from the junction between the midclavicular line and the lower margin of the 5th rib to the junction between the posterior axillary line and the lower margin of the 11th rib cage. Sihler’s staining showed that the lateral muscular branches of the intercostal nerves innervating obliquus externus abdominis gave off small branches to the 1/3 beginning of each extended muscular fiber, and then divided into an upper branch and a lower branch, innervating the middle  third of  the serrated origin of each muscle. These 2 nerve branches branched out in the middle third of each fiber, with the upper and lower branches of two adjacent fibers anastomosed, forming a “U” shape at each mid-distal fiber, where small branches were distributed to the 1/3 of the end of each fiber. In the upper half of the external oblique muscle, the nerve branches supplied the corresponding fiber, whereas in the lower half, the distal part of upper fiber was supplied by the nerve branch (upper branch) of next fiber at the lower portion.    Conclusion   ①This study can provide clinical guidance for local anesthesia over the upper abdomen and nerve block for postoperative incisional pain; ②A “wavy” dense area with nerve branches is formed at mid-distal part of the obliquus externus abdominis from the top down; ③It is recommended that the abdominal surgical incision should not cross more than four extended muscular fibers.