General Anatomy, Applied to Physiology and Medicine, Vol. 3 (of 3)

by Xavier Bichat

Hence it is not astonishing that the diseases which especially put in action the organic sensibility and the insensible contractility of the same species, should be so frequent in the mucous organs. All the catarrhal affections, both acute and chronic, all the hemorrhages, various and numerous tumours, polypi, fungi, &c. all kinds of excoriations, ulcers, &c. of which they are the seat, are derived from the various alterations of which their organic properties are susceptible.

It is also to these alterations that must be attributed a remarkable phenomenon, viz. the innumerable varieties the mucous fluids exhibit in diseases. Take for example those that are thrown off from the internal surface of the bronchia, those that are brought up by expectoration, and which we can examine better than others, because they are mixed with no foreign substance; observe how they differ, in the different affections of the chest; sometimes they have a yellowish and as it were bilious tinge; sometimes they are frothy in the vessel which receives them; sometimes they adhere to it with tenacity, and at others they are easily detached from it. Viscid or liquid, fetid or without odour, grey, white, green or even black in the morning, they have a thousand external appearances which evidently denote differences in their composition, differences which chemists have not yet explained to us. I do not speak of the cases where as in phthisis, hemoptysis, &c. foreign substances are mixed with these mucous juices. Now it is evident that all these varieties depend only upon the varieties of the organic sensibility of the bronchial glands or of the membrane upon which they pour out their fluids. According as the property is differently altered in the mucous system, it is in relation with different substances, admits some and rejects others. The same organ, the same vessels can there, according to the state of the forces that animate them, separate from the mass of blood many different substances, rejecting one to-day and admitting it to-morrow, &c.

Do you wish for other proofs of the innumerable varieties which the different modifications of the organic sensibility of the mucous membranes produce in their functions? Observe the urethra; in the ordinary state it lets the urine pass freely; in the excitement in which its forces are in erection, its sensibility repels it and admits only the semen. Who does not know that in one species of epiphora, the mucous passages for the tears are open, and that the diminution only of their vital forces prevents this fluid from flowing in them? The sensibility of the mucous surfaces is oftentimes so altered that their glands refuse to admit every kind of fluid; this happens in the beginning of some peripneumonies, in which expectoration is entirely suppressed, it is always a serious beginning, and even an indication of death, if the state of the sensibility does not change, unless a relaxation, as it is commonly called, takes place.

In general, I think that there are but few systems which deserve, more than this of which we are treating, to fix the attention of physicians, on account of the innumerable alterations of which it is susceptible, alterations which almost always suppose those of the predominant vital properties of this system, as the alterations of the muscular, nervous systems, &c. most often put in action the properties which more particularly belong to them, viz. animal contractility for one, and the sensibility of the same species for the other.

The sensible organic contractility does not appear to be the attribute of the mucous system; yet there is often in it something more than the insensible oscillations which compose the other organic contractility. For example, in the emission of semen, in which there is no agent of impulse at the extremity of the urethra, as in the evacuation of urine, it is very probable that this is spasmodically contracted to produce the jet, oftentimes very strong, which then takes place. The following phenomenon which I have observed in myself appears to belong to the same cause. In gaping, there sometimes escapes from the mouth then wide open, a small jet of fluid, which coming from the lateral parts of this cavity that it passes over, is thrown at some distance; if a surface is then before the mouth, as when we read a book, this fluid is spread in small drops upon this surface; it is the saliva which the excretory duct of Steno throws out with force. Now on the one hand this duct is almost wholly mucous, and on the other it has not at its posterior part a muscular agent of impulse. Perhaps the excretories which pour out their fluids in the deep parts of the organs, exhibit the same phenomenon. We know that the milk is also sometimes subject to a kind of ejection, when it is very abundant, an ejection which supposes a powerful contraction of the lactiferous ducts. In general, these different motions analogous to that of the dartos, of the cellular texture, &c. appear to hold a middle place between those of tone and those of irritability.

Sympathies.

There are few systems that sympathize more frequently with the others than this. Now in its sympathies, it sometimes influences and sometimes is influenced. The first Tissot calls the active mode of sympathy, the second the passive. Let us make use of this classification.

Active Sympathies.

One point of the mucous system being inflamed, irritated or stimulated in any way, all the vital forces can enter separately into action in the other systems.

Sometimes it is the animal contractility that is brought sympathetically into action; thus the diaphragm, the intercostal and abdominal muscles contract to produce sneezing from irritation of the pituitary membrane, or cough from the irritation of the membrane of the bronchia, or from that even of the surface of the stomach, which produces stomachic coughs, which, as we know, have nothing to do with affections of the chest. We know the general spasm that seizes all the muscles the instant a foreign body passes between the mucous edges of the epiglottis. Stones of the bladder and the urethra, by making the cremaster contract sympathetically, produce retraction of the testicle. Physicians might, I think, profit by the knowledge of these mucous sympathies. In apoplexy, in which the bronchia is sometimes filled with mucus that the patient cannot evacuate, the action of ammonia upon the pituitary membrane produces the double effect, 1st, of stimulating the brain as blisters do; 2d, of freeing, by the cough it occasions, the surface of the bronchia, which being obstructed, is an obstacle to the passage of the air.