Our present thorough knowledge of the combined disturbances and phenomena, that play their part in the vessels and tissues, of the body during the inflammatory action in living tissue is due to the unremitting toil of Professor Cohnheim. He was the first to speak from facts, as they presented themselves to his eye under the microscope. It was he who had the genius that suggested the examination of the whole process of inflammation, in the living tissues under the microscope. This he accomplished by narcotizing a frog, and while alive, but insensible to pain, a portion of the peritoneum or mesentery, which is almost transparent, so that the circulation may be plainly seen, was fastened with pins upon an ingeniously-devised rack or stage. The inflammation is now excited by etching the membrane with a little acid and a sharp needle, and then the object is placed under the microscope. If the operator is careful, so as not to tear or crush the vessels or tissues, and preserves the moisture, by spraying with warm water from time to time, the circulation and the abnormal processes of inflammation that are going on, may be observed and studied with great exactness for several hours. I will now describe what may be seen in the field of the microscope.
The first change to be observed is in the vascular system and within the vessels themselves; this begins with a widening of the small arteries, then of the smaller capillaries and veins. This increases the current of blood with greater velocity through the widened vessels. Sooner or later this rapidity of the current lessens; there is a marked slowness to be observed in the stream. The single or separate blood cells, which in the beginning of the observation could not be distinguished, can now be distinctly seen, especially in the veins and small capillaries, in which, from the slowness of the current, the blood accumulates. In the veins there now appears at the periphery of the current a pellucid plasmatic layer, in which there are white blood cells, that have separated themselves from the main current; the white cells either float slowly along or adhere to the walls of the vessels. This phenomenon the Germans term “Randstellung der Farblosen Blut Körperchen,” which means, bordering of white blood corpuscles. Not long after the “bordering” of white cells, a change takes place in the cells themselves, that is very interesting. The white cells become elongated and spear-shaped at one extremity, which pierces the wall of the vessel, and after a little while the sharp extremities will appear on the outer surface of the wall of the vessel, and a little later on, indeed, the entire protoplasmic cell will have emigrated into the tissue, outside of the vessel. Or, in other words, the colorless blood cells will have passed through the walls of the vein or capillary, and this constitutes an extravasation.
The first extravasated cells will soon be followed by others in great quantity, so that in six to eight hours veins and capillaries are surrounded with white corpuscles. In their normal destination these become organized into fibrous or granulation tissue; and for this reason, an organ that is the seat of chronic inflammation becomes immensely enlarged from this inflammatory accretion. We can now readily appreciate why the womb, liver or kidneys become augmented in size from inflammatory processes. Indeed, this applies to all growths and even to bone, and if a part is injured by a cut, accident or disease of some sort, precisely the same processes are at work to repair the lost tissue. It cannot fail to become apparent at once, that to understand the phenomena of inflammation is to possess the key that opens to our understanding the operations not only of most diseases, but of the healing processes of wounds and injuries. In the course of the experiment we see also red blood corpuscles transude, which are always accompanied with more or less fluid or plasma.
The above detailed account seems to explain in a clear manner the different cardinal symptoms that have become recognized features of inflammation since the time of Galen. The great vascular activity explains the redness, swelling and increased temperature. The pain can be traced to the pressure from the exudation, to which the delicate nerve filaments were exposed, while lessened function would be the natural result of nerves or tissues so compromised.
I made an attempt to initiate the reader into the science of inflammatory processes and if I have succeeded in making myself understood, then I am satisfied with having imparted a most useful lesson, because there is no process in the entire field of disease that is so general; it is almost safe to say that with the exception of functional diseases, there is perhaps no class of diseases with which an inflammatory process is not more or less associated. This is true of consumption, which is an inflammatory process excited by and around the bacilli or micro-organisms, and these inflammatory nodules are called tubercles. The growth of a cancerous tumor is associated with an inflammation. The development of a common boil is an illustration of an inflammation, breaking down or destroying part of the tissue which is inflamed. It is the same in inflammation of the lungs or pneumonia as it is in ordinary catarrh; the differences that are presented to the eye are only modifications of degree and peculiarities that are due to the difference of the tissues of which the organ or membrane is composed.
CHAPTER XI.
URETHRITIS AND NEURALGIA OF THE URETHRA.