According to the classic physiology, any body response evoked with the participation of the central nervous system is called a reflex. It includes afferent, intermediate and efferent parts. The understanding of the reflexion principle seemed to solve the fundamental problems of the curative effects of acupuncture. At first it seems to be explicable and may be used to explain most of the clinical results /functional normalization of the visceral organs and some vegetative reactions and muscular tonus changes/. At the same time there are some physiological phenomena, where the reflexion interaction doesn't exist in its classic variant. Here, first of all we must speak about antinociceptive system activity in the first (spinal) segmental portion.

It is known that gate control machanism structurally and functionally in the 1-4 Rexed layers has no reflexion interaction. The gate control activity is one sensor flow controlling /inhibition of nociceptive flow/ by another.

Another variant of the classic reflexion conception is trigemino-corporal sensory interaction. Sensory flow from the trigeminal complex is stated (Durinian R.A., 1976) to exert some significant effect on the corporal sensory flow. This interaction may result both in mutual inhibition and enhancement of one flow by another.

In our experience this principle is widely used. Another example of sensory interaction may be the use of auricular points for curative purposes. Five sources of afferent innervation of the floor of the auricle is a unique model of interrelation of different cranial nerve sensory systems. The reflexion responses of such interaction are significantly limited in numbers as compared to the generating physiologic phenomena which have no reflexion nature. Strictly speaking, the appearance of the auricle floor active points is also explained by sensory interaction in truncus cerebri by a change of excitability and neurotrophic control of the receptor groups in the ear.

It is common knowledge that auricular acupuncture points are not very active in the norm and are not revealed as a rule.

These important clinical and physiologic comparisons make it possible to assume that the reflexion in phenomenon in the clinical evidence of acupuncture is a part of more prevalent way of physiological reactions of afferent (sensory) interaction. The sensory interaction being the most universal way of physiological function regulation has some significant "advantages" before the reflexion one from the structural and functional point of view. The reflexion response of the body (system) is a precise result of the varying and wide sensory interaction, the complete justification of its biological nature!

Mechanisms of sensory interaction are universal. Predominantly they present presynaptic inhibition and cascade augmentation due to inlet signal multiplication.

Postsynaptic inhibition and hyperpolarization mechanisms of the postsynaptic membrane are known to be more predominant in the reflexion activity. Taking this into consideration the regulated afferent flow, made by the doctor, is a basis of acupuncture while the reflexion interaction is a part of this interaction.