General information about the reception

For perception of stimuli coming both from the external environment from different organs of our body, are of special education - receptors. Densely scattered all over the body, they keep the Central nervous system aware of all the events.
In the evolution of the receptor apparatus has achieved a significant degree of specialization, adapting to the perception of certain stimuli. An example of such a pronounced differentiation can serve as visual, auditory, olfactory receptors, which is characterized by extremely low threshold to adequate stimulation and practically does not respond to inadequate irritation.
Skin receptors (the so-called surface sensitivity) do not differ in such perfection. To surface sensitivity include tactile, cold, heat and pain. According to a widespread view, each of these types of sensitivity correspond to their receptors, separate pathways and specific cortical centers. Projection receptors on the skin called "sensitive points". In accordance with the above mentioned kinds of sensitivity there are tactile, cold, heat and pain points.
As is known, in relation to the pain receptors there are two diametrically opposite points of view. According to some authors, irritation any receptor may, at the proper intensity to cause pain. Others, on the contrary, believe that there are special pain receptors. They are free nerve endings. However, the question about the existence of an independent system of pain sensitivity is highly controversial.
Until comparatively recently, some foreign authors (Kantorovich, 1932; Walkhoff, 1939) argued that the tooth has one form of sensitivity, pain, and especially widely represented in the pulp and enamel-dentinal the border, and healthy dentin differs low sensitivity to pain. To external stimuli, it becomes extremely sensitive only after the loss of enamel cover, not immediately but after some time.
Our research of the sensitivity of dentin showed that enamel-dentinal border painful far from all over and that the dentin areas are deprived of sensitivity.
As stated, the threshold of irritation electric current in a perfectly healthy teeth, and when neuritis alveolar nerves or after anesthesia and very intense irritation cause tactile sensations.
Thus, the presence of tactile sensitivity in the teeth is not in doubt. In favour of this point of view, and says the following well-known fact: in the event mouth, neuritis alveolar nerves, wiring or infiltration anesthesia appears numbness tooth, which is seen as paresthesia associated with tactile feeling.
The feeling teeth cold is a phenomenon familiar to everyone. When applied to the vestibular (or speaking) the surface of the pick cotton ball moistened with water temperature below 20 degrees, there is a pronounced feeling cold. When water temperature is below the 11th appears mixed feeling cold and pain. The water temperature is above 40 degrees calls in the cutters are feeling the heat, and above 60oC - mixed feeling of warmth and pain.
Consequently, the tooth has all kinds of skin sensitivity - pain, tactile, cold and heat. However, this sensitivity is characterized by a certain originality and has a number of features typical of hyperpathia: painful, explosive nature of pain, the disparity between the power of irritation and power of feelings (light touch probe to the naked neck or pulp can cause a very sharp pain, not the adequate intensity of irritation), expressed by the radiation of pain (a painful, far spreading pain in diseases of the tooth is well-known), a relatively high consequence (incurred after thermal or mechanical irritation pain lasts for several minutes after removal of stimulus), the ability to distinguish only the extreme temperature irritation (relatively clear feeling of heat or cold tooth occurs only when exposed to relatively high or low temperatures, in contrast to, for example, the skin), imperfection localization sensations (sick very often can't tell the patient tooth, often specifying it in the opposite jaw). All this gave us the reason to assume that the tooth peculiar protomoteca sensitivity.
Systematic observations over the sick, suffering from causalgia, the so-called sympathalgia, often with vasomotor and trophic disorders, and on patients who have had expressed phenomenon of hyperpathia, has long led us to the conclusion that between these forms are not qualitative and quantitative differences, all these types of pathology due to violations of the sympathetic innervation sensitive systems of the body, or, in other words, violations of the sympathetic innervation of those or other analyzers. The sympathetic nervous system, performing their adaptation and trophic role in the body, regulates and sensitivity, adjusting and adapting it to the perception of many stimuli. Violation of the sympathetic component sensitive innervation occurs or hyperpathia, or "sympathalgia", or causalgia.
The presence of hyperpathia (or protomotional sensitivity) in perfectly healthy teeth indicates imperfect sympathetic innervation dental tissues.
In the teeth occurs special, apparently, only one of them is peculiar feeling is set on edge. The latter appears under the influence of acids, operating not only on the teeth, but also on the mucous membrane of the oral cavity and causing irritation many receptors, including taste. For the study of sensations that occur in isolation in the tooth, we used the following methodology. Subject to study teeth were covered with cotton rolls and thoroughly dried. Moisten a cotton ball with a solution of citric acid, within 2-3 minutes rubbed in a specific area of the tooth (cutting edge, chewing surface, hillocks, vestibular surface). Under the action of citric acid at the surveyed had a sensation of numbness, as after anesthesia, which is often combined with more or less pronounced feeling of pain in the teeth the gnashing jaws. These unpleasant sensations in some people passed quickly, others kept many hours. Thus, the edge is a complex feeling, due to the simultaneous different receptors irritation of the tooth. Along with this we saw people with 3 minutes of rubbing citric acid did not cause no symptoms. These people stated that they are set on edge appears only under the influence of large doses sour, with moderate and passes quickly. The occurrence or absence of mouth, fast or slow disappearance of emerging experiences indicate the different barrier functions enamel, about the different speeds of exchange processes between the hard tissues of teeth and saliva.