The meridians correspond to the 12 months of the year similar to astrological tables used for 2,000 years in Western medicine, and to the 12 organs or bodily functions: large intestine, stomach, small intestine, gallbladder, bladder, circulation sex (associated with heart and blood), lungs, spleen, kidney, heart, liver, and “triple- warmer” (associated with respiration, digestion, reproduction). Each meridian is affected by these organs, and its function is to regularize the energy that animates them.
Six of the meridians are situated on the external surface of the limbs; they are traversed by the Yin type of vital energy, and they correspond to the parasympathetic system. Each Yang meridian has a corresponding Yin meridian. These meridians are joined two by two at their extremities by vessels of junction, which are called upon to regularize the excess of energy from a Yang meridian by having it pass into the corresponding Yin meridian. Thus, if there is an excess of energy in the Yang meridian of the stomach, it is drawn off into the Yin meridian of the spleen. The Lo passage points are used for this effect.