Temperature Regulation

R.J. Watkins, D.C. – 1964

Appendix V

 

The gross patterns of temperature regulation are well known, including the hypothalamic centers as both a sensor and control center. These in turn, regulate the gross mechanisms of shivering, perspiration and others. A part of this mechanism includes a general blood volume into the skin. The heat exchange from the skin by radiation, convection, conduction and the added point of evaporation are generally known. Super-imposed upon this general pattern, is another highly significant segmental pattern previously mentioned.

The segmental control of skin blood volume cannot be mediated through the general sympathetic nervous system, the units of which each cover an area of several spinal segments. Our investigations have shown that instead of being only 26 segments from occiput to sacrum base there are frequently two or more demonstrable zones within each vertebral segment. This necessitates a much more localized intrasegmental mechanism. It has been generally assumed that the sympathetic stimulus causes only vasoconstriction of the terminal arterioles within the skin. However, for over 50 years physiologists have been aware of experiments in which the posterior nerve roots have been cut and subsequent stimulation of the distal segment resulted in vaso-dilation of the skin supplied by that posterior nerve roots ganglion. This has been explained as an anti-dromic reflex involving several branches of a single neuron. Regardless of the final decision of the anatomists, we are consistently demonstrating sharply demarcated zones of vaso-motor control within a single vertemere. One of the reasons for using this mechanism as an indicator in monitoring the central neurophysiology is that it is a constantly functioning mechanism quite accessible to us in the immediate area of the spinal column. This gives us the advantage of being able to do several parallel checks with a minimum of patient movement.

This practical method of monitoring the state of the vasomotor control mechanism is in effect a window into the inner workings of the nervous system. On the basis of our experience to this time, we find this to be the most accurate indicator available of a general functional state of a nerve segment in question. The mechanics are then dependent on a method of measuring not the blood volume, but the blood flow through the skin. We have demonstrated many times that after the skin is slapped or pinched there is an immediate flush of blood into the area to leave a red welt. For a few seconds there is an increased local temperature but the gross dilation leaves a stasis so that the temperature is very quickly dissipated in to the surrounding tissues and does not leave a hot spot one might expect. Therefore, we are able to accurately measure heat transferred either into or away from the skin. In this way we are able to monitor the changes in rate of blood flow. Such monitoring is thus of a central nervous system segmental function of vasomotor control which reflects the state of total functional capability of this segment. This monitoring has been done with matched thermisters after a preliminary cooling of the skin with alcohol in order to offset the general warming of the skin under the clothing. If the back has been bared to the open air in the resting state for about 15 minutes, this preliminary chilling is often not necessary. The rate of heat flow through and away from the skin is of sufficient segmental demarcation to make significant graphs.

The usual area of major nerve malfunction or interference results in constriction of the blood flow through the skin and a consequent reduction in the heat transfer. This means that contrary to a popular misconception, the area of nerve involvement is a cold strip instead of a hot strip. Relatively minor and acute conditions are frequently unilateral and can be demonstrated with a differential type of heat detector. More significant, chronic areas of involvement are usually bilateral and do not show up at all on a differential type of indicator. This is an additional reason for using two separate sensors and indicators. This consequently involves a much more expensive two channel recording instrument for doing permanent graphs, but the results are more informative by comparison. The ideal graph with a differential unit is a straight line. The ideal with a dual channel unit is parallel lines. The percentage of total complete correction are about 3% so pattern studies have been done for years. Even their objective is striving toward the ideal straight lines.

Perhaps you have realized already that the temperatures which we are recording are skin temperatures based upon the blood flow and cannot in any way be construed to be “nerve heat”. The caloric changes within a nerve trunk have been demonstrated and are so minute as to be measured with great difficulty at the nerve trunk itself and are impossible to measure from the surface of the skin. The perversion of the function of a nerve segment, however, does result in a definite aberration of the local intra-segmental vasomotor control which is quite probably mediated through the process of a single nerve cell (anti-dromic reflex) thus giving us very close demarcation. Also, you may realize that we are not measuring skin temperature per se but are measuring heat transfer through the skin which is a direct function of the blood flow. Fortunately, this is a mechanism which can be measured before and after each individual contact of your chiropractic technique and it has become a very accurate indicator of the total changes in neurophysiology throughout the various stages of single adjustment.

Occasionally we find a marked immediate improvement has been made after each of several successive contacts. In such cases we have continued in one day with as many as 25 or 30 different contacts before the desired improvement was accomplished. This will be demonstrated later with graphs of actual cases but for the moment is mentioned only to show the immediate practical value of this monitoring method as an indicator; as a window for an insight into the inner working of the neurophysiology by monitoring intrasegmental function of the vasomotor control.

Herein we have attempted to show a brief introduction into the anatomy and physiology involved with this segment of total body temperature regulation. More details of this background with more details on related spinal mechanics will be presented as we become more familiar with the various instruments.