Nervous system of human uterus during labor

Today it is a rather obvious fact, that the uterus during labor does not have any elements of nervous system, in particular, nerve endings and conductors that could participate in the direct regulation and modulation of the contracting activity of myometrium. Basing on our own research and the literature material we have come to understanding that the physiological process of uterus denervation is one of the organic indications of uterus maturation. The very factthatthe smooth muscle cell of myometrium or the cell structures of the vascular system of uterus have areceptor apparatus, able to react on neuromediators too, does not give us the right to state that uterus during labor has a system of straight nervous regulation of the contracting activity of myometrium and respectively gives us the basis to state that a system of humoral control of this action is functioning during the labor process. It is the sixth fundamentally important proposition.

Nevertheless, many text books and publications still continue teaching some compromising concept that the human uterus has a special conducting system, identical to the heart conducting system from the morphological and physiological point of view. The modern way of the concept is greatly presented in works by Professor Ermoshenko B. and co-authors as well as in the Main National Guide. The main idea of the concept - that is, by the way, is fifty years old - is quite simple. Uterus has a sinus node (similar to pacemaker) that generates impulses able to start the contracting of the cells of myometrium. With the help of high-permeable contacts the latter unite into some huge functional syncytium. It means that cells of myometrium themselves become a system “conducting” this impulse. We have recently analyzed this speculative concept full of error limits and assumptions in detail. We have once again confirmed those proverbial facts stating that during the fifty-year old existence of the sinus node concept its actual presence in uterus still has not been detected. Secondly, we have shown that gap junctions unite only part of myocites and only in small cylindrical beams proving that emergence of a “functional syncytium” in myometrium during delivery is out of question. Nevertheless, in conclusion of the review Ermoshenko B. and co-authors write the following - “…we have every reason to say about a conducing system of uterus with its main defference from the analogical system of heart being in the absence of documented (annotated) pacemaker. If it is not going to be detected over there we will have to agree with the opinion of Savitsky G. stating that the contractions of smooth muscle cells are caused by the peaks of maximal stretching stipulated by the dynamics of the blood flow in the venous channel of myometrium. Seven years have passed since the review by Ermoshenko B. and co-author was published. Pacemaker in uterus is still not found and we dare to ensure the reader that it never will be, if it is a matter of a separate morphofunctional lump that manages the contracting activity of myometrium. Myometrium does not “need” it because each of the myocites has its own pacemaker ensuring the contracting activity (autorythmics) of the cell.

Дата добавления: 2015-10-30