The discovery of modern evolutionary anatomy shows that the persistent median artery in the upper arm is a common variant with an increasing trend. This phenomenon can explain well the transition from the eleven meridians described in the Han silk and bamboo slips to the twelve meridians finalized in Neijing and the addition of the hand- jueyin meridian in Han dynasty. After systematic analysis and comparison, the author proposes the hypothesis that "yin meridians are arteries, and yang meridians are nerve-like structures" to explain the meridian theory prior to acupuncture and acupoints in the Qin and Han dynasties. It is clear that over two thousand years ago, Chinese physicians already described the distribution, physiology, and pathology of the six main arteries and six important nerves in the human extremities. The finding suggests that it was the addition of acupuncture and acupoints that had changed the direction of TCM development in Neijing or later and promoted the maturation of qi and blood, meridians, and zangfu theories.
现代进化解剖学研究表明上臂遗留正中动脉是常见的解剖变异，且有增加趋势。这个现象正好能够解释汉简帛十一脉到《内经》十二经脉的转变和手厥阴经脉的增补。经系统分析对比，笔者提出“阴脉为动脉，阳脉似神经”假说，用以解释在针刺和穴位出现之前的秦汉时期经脉理论。指出早在两千多年前，中国古代医家就描述了肢体的6条主要动脉和6条重要神经的分布、生理和病理。证据提示，可能是由于针刺和穴位的引入改变了《内经》以后的经脉理论发展方向，促进了气血、经络、脏腑归经等理论的形成。.
Keywords: Qin Han medicine; eleven meridians; meridian essence; meridians; persistent median artery; silk book.