Microscopy of structures surrounding typical acupoints used in clinical practice and electron microscopic evaluation of acupuncture needles

Abstract

Although the general functionality and structures of acupoints have been studied, there has been little insight into their underlying morphology and physical characteristics. We describe the microanatomical structures surrounding acupoints, the electron microscopic appearance of the needles, and the physical effects of acupuncture needling on the fascia. We injected heparinized blood solution through thin needles at seven known and commonly used “sweat acupoints” in eight fresh, unembalmed, cryopreserved human cadavers to mark the needle positions, and later, during histological examination, to identify them. After the solution was injected, samples were dissected and prepared for histological examination. We examined 350 cross‐sections of five different paraffin wax sections from each acupoint microscopically. Acupuncture needles were photographed and superimposed on the cross‐sectioned tissues at similar magnifications. Needles were also examined under a scanning electron microscope to judge the roughness or smoothness of their surfaces. A greater conglomeration of nerve endings surrounded the acupoints than in tissues more than 1–3 cm distant from them. Nerve endings and blood vessels were in close contact with a complex network of membranes formed by interlacing collagen fibers, and were always enclosed within those collagen membranes. Nerve endings were found within hypodermis, muscles, or both. Scanning electron microscopy demonstrated the three‐dimensional shapes and sizes of the needles, and the degree of roughness or smoothness of their polished external surfaces. We demonstrate a delicate arrangement of nerve endings and blood vessels enclosed within complex collagen membrane networks at acupoints within the hypodermis and muscle. This arrangement could explain why needling is an essential step in the acupuncture process that provides favorable outcomes in clinical practice.

Accuracy of injection pressure measurement at peripheral nerves using high-resolution 40 MHz ultrasound in an anesthetized porcine model

“…First, fluid injected at high-pressure liquid is directed towards compliant intraneural fat, which offers much less resistance than fascicular tissue 27. In this scenario, injectate does not enter the fascicle but instead exits towards the intraneural fat and provides an element of safety 16.…”

Electroacupuncture for mild-to-moderate dry eye: study protocol for a multicentre, randomised, single-blind, sham-controlled trial

“…In terms of body points, ST36, LI4 and LR3 are frequently prescribed for all sorts of diagnosis patterns based on network analysis. 53 The association rules analysis also shows that TE23 and LI4 can be used as the core point groups in treating DE. 52 The latest meta-analysis also suggested that 2–3 times of acupuncture per week for 21–30 days might be the most appropriate option for managing DE.…”

“…Among them, BL2, TE23, EX-HN5 and ST2 are the most commonly used periocular points in treating DE 51 52. At the local points, a mass of nerve endings and blood vessels are distributed in the hypodermis and muscles, interlacing with the collagen fibres 53. Benefiting from this microanatomical structure, EA at BL2 and EX-HN5 can effectively stimulate the periocular nerves.…”

“…Benefiting from this microanatomical structure, EA at BL2 and EX-HN5 can effectively stimulate the periocular nerves. In terms of body points, ST36, LI4 and LR3 are frequently prescribed for all sorts of diagnosis patterns based on network analysis 53. The association rules analysis also shows that TE23 and LI4 can be used as the core point groups in treating DE 52.…”

“… 51 52 At the local points, a mass of nerve endings and blood vessels are distributed in the hypodermis and muscles, interlacing with the collagen fibres. 53 Benefiting from this microanatomical structure, EA at BL2 and EX-HN5 can effectively stimulate the periocular nerves. In terms of body points, ST36, LI4 and LR3 are frequently prescribed for all sorts of diagnosis patterns based on network analysis.…”