He was born in the Lithuanian town he served as, he graduated from Chernigov gymnasium and in 1853 he entered the medical faculty of the University of Warsaw, but not satisfied with the teaching of physiology, went to the famed University of Kyiv, but here the teaching of physiology seemed narrow. Finally at the University of Berlin he becomes a specialist, a neurologist, and in 1864 receives the degree of doctor of medicine in St. Petersburg. Now more in Leipzig, in the "world of school" by Ludwig. Here old Dr. Ilya Fabian Gottlieb Zion receives from the great Carl Friedrich Wilhelm Ludwig the research topic " Innervation of the heart: regulation of circulation". As usual Ludwig involved in the experiments, which decide to put in rabbits. Was it a Fluke or Ludwig already knew something?
For a start was required to expose the wandering and sympathetic nerves. The easiest way to do it on the neck, where both nerve lie under the skin (on the sides of the trachea one vagus and one of the sympathetic nerves on each side). To them fit and common carotid artery, one of which is entered cannula connected to the gauge system Ludwig. Now the work begins with nerves.
And then, it was found that on each side of the trachea the animal has not two, but three nerve, the third quite thin. What is it? A variant of development, ugliness? No, in any case, not the ugly : the rest of rabbits was also the third nerve. Specific features of rabbits?
The preparation has shown that new nerve enters into the chest and gives many branches heart and the aorta. Central end nerve reached complex ways oblong brain, where Ludwig and his students found vasomotor center, regulating blood pressure. Wanted to know what does "third nerve". For a start it is cut and have not noticed nothing: neither the frequency of the heart or blood pressure has not changed, the breath of the parish remained without change. Then at the annoying electrodes laid the peripheral end of the nerve, but on and off power did not affect the circulation of the rabbit. It became obvious that the nerve - sensitive, and physiological reactions can be expected only in response to irritation its Central segment. Here he lies on electrodes is included current and brings one of the most important discoveries in physiology.
"Central" irritation of the open-Zion and Ludwig nerve led to immediate and extremely important consequences. First of all, your blood pressure to rapidly and deeply fell (three times!). The fall was so significant that even the diameter of the aorta decreased with the naked eye. The second effect of the irritation of nerve was small ischemia of heart contractions. Immediately the question arose: is not reduced if the pressure due to this ischemia? The response was immediate: after transection heart twigs stray nerves blood pressure in response to irritation of the "third nerve" fell as intensively as in the case of integrity of vagonov and heart rate at this time did not become less. It means that the pressure in the arteries did not drop as a result of reduced cardiac output, and due to the reduction of the resistance of the vascular blood flow. Scientists immediately on the operating table determine what the vessels involved in the reduction of blood pressure. This became clear when Zion drew attention to unexpected detail: the rabbit intestine during reduce blood pressure became redder, his vessels expanded. One could assume that the vascular pool guts becomes more go for blood at the time when the Central irritation raw nerve. This assumption required additional evidence, as both could expand and other vessels.
The bowel was denervated, and then the effect of lowering the pressure in the arteries to reproduce failed: initial suspicion was confirmed.
So, open doubles sensitive nerve of the heart and aorta, which excitation leads to reflex reduce blood pressure by reducing prekapilliarnae hydrodynamic resistance mainly in the vessels of the intestine. Zion and Ludwig rated their opening correct as opening nervous reflex regulation of blood pressure. They believed (and quite rightly)that sensitive nerve endings in the heart and the aorta excited when the pressure in this area, and this causes a reflex reaction - lowering vascular resistance. All this reflex apparatus was regarded as a system of self-regulation of blood pressure in the pulmonary circulation. Nerve received a beautiful Latin name the neuros depressor Cordis, i.e. the nerve of the heart, lowering pressure. It was opening feedback - such term shall enter in the XX century Norbert Wiener.
This article Ziona and Ludwig (1866) it became clear that they opened reflex mechanism that supports (among others) the constancy of the internal environment of the body. The idea of the necessity of such consistency was shortly before it made a great French physiologist Claude Bernard. The constancy of the environment means constancy of acidity (pH), chemical composition, temperature, and many other indicators.
Naturally, the internal environments vary depending on rest or physical work, health or illness, etc., One of the most important parameters of blood circulation, providing homeostasis, i.e. the constancy of the internal environment is blood pressure. First of all, it is cause the blood circulation.
Next, from blood pressure depends on the pressure at which the blood is included in the capillary, and hence, the pressure at the exit from the capillary. Therefore, the blood pressure should be adjusted especially vigilantly, and no matter how varied other indicators circulation (heart rate, blood, heart release), blood pressure remains the least vulnerable value, the most constant, such as body temperature, which influences the course of biochemical reactions, metabolism in the body.
After the opening of Zion and Ludwig and observations Claude Bernard, who found that vascular tone is determined by the activity of the sympathetic vascular centrifugal nerves, established view of vascular regulation as exclusively on reflex. This is not entirely accurate, it was subsequently discovered what is now called the autoregulation of blood vessels - about which we talked in the Preface, though not exhausted issue. So, we not say that the vessels are sensitive not only to mechanical tension, but also to speed the flow of blood in their veins. If the blood flow is accelerated, then the potential difference between the inner and outer membranes of the heart changes and increases the sensitivity of vascular muscles to nerve influences. And the sensitivity of the vascular wall to changes in pressure, and changes in its responsiveness to the nerve impulses under the Effect of the deceleration or acceleration of blood flow - all the properties of the vessel wall. However it was found out much later. And while'll leave on time with Karl Ludwig. Zion goes home, inspired by their success, new ideas, hopes, knowledge, ability to work as Real Physiologists... He is bringing to Russia the worldview Ludwig, developed it in cooperation with Dubois-Reymond, Helmholtz and the Bridge and was most clearly expressed in a letter Dubois: "the Bridge and I - we swore to reveal the truth that the body is not any other powers besides the physical and chemical".
Goodbye, Leipzig, goodbye, Thomas Church, where there is an organ playing Johann Sebastian Bach, goodbye, Auerbach-Keller, whose walls were autographs of Goethe, forgiving, Professor Ludwig...
Petersburg. Shaded rain silhouettes familiar streets and clouds without end. Here, in this city, just left, bypassing censorship, separate edition Sechenovsky "Reflexes of the brain". Three years ago Zion read them in "Medical Bulletin" - special edition where this explosive work not attracted the attention of the authorities. Now, the result may be different. Physiology became the sedition, it is hoped that Ivan Mikhailovich will not burn beams damp straw along with three thousand copies of his books in the midst of the Senate square...
Fate did not indulge Ziona, despite his brilliant scientific progress. Ilya Fabian Gottlieb enrolled as a Privat-docent of the Petersburg University. Privat-docent - this is a part-time position. Who held her usually assigned teaching optional course with optional visit, without tests and examinations. Privat-docent, however, not everyone is allowed to do experimental work, to which he devoted himself Zion. This time he went together with his brother (also a doctor) in Berlin laboratory, Dubois-Reymond. Brothers supposed to find out action of the sympathetic nerves of the heart.
The work was terminated unexpectedly pleasant event: the Paris Academy of Sciences has decided to celebrate a remarkable finding Ilya Fabian Gottlieb Ziona and Karl Wilhelm Friedrich Ludwig first Monotonously prize.
Paris. Meeting with Claude Bernard and President of the Paris Academy of Sciences Mariam that, solemnly awarded the prize Ludwig and Zion. And... interrupted studies are underway. In 1867 out of print article brothers Zion on the effect of excitation of the sympathetic nerves of the heart. Irritation of these nerves leads to the strengthening and increase of heart.
Finally laureate Monotonously prize of the first degree, author of two of the most important discoveries of the century, Privat-docent of Zion, shaded already world fame, returned to St. Petersburg University.