A Loop System along Skin with Transmitted Pilomotor Line for Vibrating Regulation of whole Body Function
Authors: Liu Li-Yuan 
Published: November 2021

In Chinese traditional medicine (CTM), meridians are described as a set of linear and longitudinal pathways along body skin. Acupuncture at acupoints provoke signals that transmit along the pathway and arrive to focal organs, which can treat more than one hundred of diseases. The pathway has been proved by modern anatomical and physiological researches. Linear structure and activity: There exist a loop system along body skin, consisted of a complex of sympathetic-arrector pili muscles (AP muscles) and concentrated mast cells in the rats. Along certain skin pathway, abundant sympathetic endings distribute within the AP muscles, which are appeared as sympathetic-substance lines (SSL) by macro-autoradiography. Under the line, mast cells are densely distributed. After shaving rat’s hairs, the new hairs firstly grow along some lines and loops, called hair-loop-lines (HLL). Acupuncture or injection of α receptor agonist at an acupoint produce a pilomotor line and simulate strong acupuncture effect, accompanying with neurogenic inflammation along the line in the rats. These three lines are coincident each other. The pilomotor line can be blocked by local injecting of α receptor antagonist, by crosscutting off skin or by applying procaine along the line, or by peritoneal injecting of cromoglicate. All these suggest that the pilomotor line along the SSL is the pathway for transmitting acupuncture signals independently and then producing acupuncture effect. Mechanism of linear transmission: The local piloerection stimulates the nerve nets of sympathetic endings and low threshold mechanical sensitive C-fibers around the hair follicles, whose excitation transmit to adjacent hair follicles by cross innervation and provoke new piloerection and neurosecretion respectively by axon reflex. Excited peripherical endings of C-fibers release neuropeptides (SP and CGRP) that stimulate mast cell degranulation. The released histamine stimulates C-fibers to produce gentle itch and further release of neuropeptides from C-fibers. Moreover, histamine stimulates AP muscle contraction. Thus, a positive feedback loop along hair follicles—C-fibers—mast cells is initiated and the pilomotor is enhanced and transmitted, accompanying histamine-mediated inflammation and sensation. The diffusion of released NA and histamine to adjacent skin also play important role in the transmission. Both axon reflex and diffusing action are united to cooperation for chain transmission of acupuncture signals. Mechanism of acupuncture effect: The acupuncture effect does not unidirectionally increase or decrease, but oscillate periodically, with about 28 min per circle. It is assumed that acupuncture leads the whole-body function change undulately and every organ in the body finds their own balance point through vibration. Therefore, acupuncture is auto-regulation, bi-regulation and vibrating regulation. The vibration is assumed by periodically excited and inhibited afferent signals from pilomotor line that lead periodical oscillation of whole CNS and the following oscillation of whole-body function.As a sum, under the guidance of CTM, a novel and unknown linear system hidden along skin have been discovered, which play an important role in the horizontal and integrative regulation on whole-body function, as expected in the integrative physiology. Importantly, there is a new type of mechanical transmission of signal.