Mucous membrane

“ The mucous membrane in the chronic state of the disease presents a rather dry, indolent and bluish appearance, except that here and there the tissues show more activity of the disease, more especially so over the anal region, due to harsher disturbance during the act of stooling. In the subacute or acute stage of the inflammatory process there is more general redness and puffiness of the mucous membrane, or a swollen condition with increased discharge of mucus and perhaps some blood. ”

“ That these variations distinguish them from serous membranes, whose aspect is everywhere the same, as may be seen by comparing the pericardium with the peritoneum, &c. (2) The sensibility of mucous membranes varies in a very peculiar man [69] ner in their different portions: thus an emetic irritates the stomach, but not the conjunctiva; the pituitary membrane perceives only odours; the mucous surface of the tongue flavours, &c. On the contrary, the contact of all kinds of bodies with the naked serous membranes produces phenomena exactly analogous. ”

“ Every mucous membrane exhibits two surfaces, one adhering to the neighbouring organs, the other free, covered with villi, always moistened with a mucous fluid. Each deserves particular attention.
The adhering surface corresponds almost everywhere with the muscles, either of animal or organic life. The mouth, the pharynx, the whole alimentary canal, the bladder, the vagina, the womb, a portion of the urethra, &c. exhibit a muscular layer embracing on the outside their mucous tunic which is within. ”

“ It is curious to notice how our body is wrapped in membrane. On the outside, is the skin protecting from exterior injury, and, on the inside, is the mucous membrane reaching from the lips to the innermost air cell of the lungs. Every organ is enveloped in its membrane. Every bone has its sheath. Every socket is lined. Even the separate fibers of muscles have their covering tissue. The brain and the spinal cord are triply wrapped, while the eye is only a membranous globe filled with fluid. ”

“ The mucous membrane lining the alimentary tract is the part most subject to pathological alterations, and in this connexion it should be remembered that this membrane differs both in structure and functions throughout the tract. Chiefly protective from the mouth to the cardia, it is secretory and absorbent in the stomach and bowel; while the glandular cells forming part of it secrete both acid and alkaline fluids, several ferments or mucus. Over the dorsum of the tongue its modified cells subserve the sense of taste. ”

“ Such feelings are at their height during an acute mucus storm, which is an indication of increased inflammation in all the inflamed tissues, causing secretion of a great quantity of mucus or membranous casts. No doubt much of the inflammatory exudate from the mucous membrane, from the muscular structure of the organs, and the connective tissue surrounding and supporting the organs, passes into the sigmoidal and rectal canals, while a portion is absorbed into the system. ”

“ A closed end speculum, with a proportionate slot and smooth corners, can be slowly rotated without any difficulty where the mucous membrane is not very loose and baggy and no prominences in the route. ”

“ We cannot, however, ignore the immediate influence of the medium, on recalling the facts above named, or on remembering the further fact that an inflamed surface of skin, when not sheltered from the air, will throw out a film of coagulable lymph. But that the direct action of the medium is a chief factor we are clearly shown by another case. Accident or disease occasionally causes permanent eversion, or protrusion, of mucous membrane. After a period of irritability, great at first but decreasing as the change advances, this membrane assumes the general character of ordinary skin. ”

“ Structure.—The wall is composed of four coats, the mucous membrane, the submucosa, the muscular coats, and the fibrous sheath or tunic. The mucous membrane is pale and is covered with stratified squamous epithelium.
The mucous membrane is loosely attached to the muscular coat by the submucosa. Except during deglutition it lies in longitudinal folds which obliterate the lumen. Opening from the mucosa are lenticular glands, which may be seen on inflating an esophagus and looking through its transparent walls. ”

“ Leucorrhea is merely an abnormal increase of a normal secretion. All mucous membrane secretes mucus in small quantities—enough to keep the membrane moist. When from any cause this secretion is increased, we have what is called a catarrhal condition. As all cavities that communicate with the air are lined with mucous membrane, this catarrhal condition may exist in the nose, the throat, the eyes, the ears, the bowels, or the reproductive organs, and will be named according to the location. ”

“ In chronic inflammation of the rectum and colon there is more or less discharge of mucous, and in some cases of membranous, desquamation, with yellow or bloody mucus. The shreds, cords or complete tubular casts are discharged constantly or at varying intervals. The quantity and character often alarm the sufferer. The discharge is nothing less than a thick, tenacious mucus that had formed a thin coating on the inflamed mucous membrane, and become exfoliated in casts or thin shreds—the result of many years of morbid intestinal exaggerated action. ”

“ The affection of an organ is not a necessary consequence of that of its serous membrane, and reciprocally the organ is often affected and the membrane does not become diseased. For example, in the operation for hydrocele, the testicle remains almost always sound in the midst of the inflammation of its tunica vaginalis. The inflammation of the mucous membrane of the intestines is not a consequence of that of their peritoneal covering ”

“ The entire course of the tortuous nasal canal is lined with mucous membrane, and this membrane is of a highly vascular structure. That is to say, the whole tissue is flushed with blood by a perfect network of vessels, over which the air we breathe passes, and from which it borrows the requisite heat. The mucus which is secreted by the membranes is also advantageous in rendering the atmosphere suitably moist. ”

“ By the hypodermic method of treating mucous sacs some escharotic is employed with the object of causing the absorption of the sacculated mucosa. The object to be accomplished ought to determine the proper strength of any escharotic used. Whatever will absorb the mucous membrane involved in the sac in the slowest and mildest manner is the best remedy or the best way to employ any of the tissue absorbers you might select. ”

“ Applied to the mucous membrane, carbolic acid turns the epithelial covering white; the epithelium, however, is soon thrown off, and the place rapidly heals; there is the same numbing, aconite-like feeling before noticed. The vapour of carbolic acid causes redness of the conjunctivæ, and irritation of the air-passages. [171] If the application is continued, the mucous membrane swells, whitens, and pours out an abundant secretion. ”

“ Preternatural thickening of the membrane is often of very considerable extent: deposition of matter beneath it appears to be confined to the situations of the mucous glands. These glands are found in all states and stages of disease from the least to the greatest enlargement, and from the mere abrasion of their surface to the entire ulceration of their substance. Perhaps one of the glandulæ solitariæ enlarged and covered with inflamed mucous membrane may constitute the only morbid appearance discernible in the intestine ”

“ Bacteria gain admission to the living tissues under natural conditions, by penetrating any of the mucous membranes which they can reach, or by entering open wounds. It may be said in general that an intact epidermis is almost a complete protection against infection, and that an intact mucous membrane is a good protection. ”

“ The construction of these two membranes may easily inform us, without having recourse to fanciful hypotheses, how disease, affecting any part of this membrane, either internally or externally, may pass to any other part and affect the whole; and thus how a faulty digestion in a lady, a disease of the investing or mucous membrane of the stomach, may show itself in eruptions on the face. ”

“ The mucous membrane is, like the skin, well provided with nerves, and has a mode of sensation peculiar to itself. Every villous point indeed has a nervous fibre ramified on it, to give it the necessary sensibility to its own stimuli. ”

“ Muco-serous exudations under one or more layers of the recto-anal mucous membrane finds its way down to the integument around the anus, and being of a very irritating character, greatly increases the inflammatory process in the tissues it comes in contact with. Thus the increased inflammation and blood stasis and the augmented serum unite in hurrying the development of skinny tabs and the more or less capacious muco-cutaneous rugæ and sacs. ”

“ Membranes and substance of brain healthy, but more fluid than natural in the ventricles. Thorax. Mucous membrane of bronchi greatly inflamed and thickened; bronchial tubes full of mucus mixed with pus; pleuræ of left side of chest extensively adherent; substance of left lung healthy excepting some slight patches of hepatization. Abdomen. Mucous membrane of small intestines extremely vascular, in many places presenting the appearance of ecchymosis; at the valve of the colon several small ulcers; other viscera healthy. ”

“ There were cases in which the lower segment of the small intestine, most marked immediately above the ileocæcal valve, extending thence upward, was of a dark reddish-brown color, the mucous membrane being covered with superficial hæmorrhages. In many cases the mucous membrane appeared to be superficially necrosed, and covered with diphtheritic patches. The intestinal contents in such cases were not colorless, but consisted of a sanguinolent, ichorous, putrid fluid. ”

“ Having noticed how distended the blood-vessels of the mucous membrane naturally are, it will not be difficult to understand how slight a disturbance of the balance of blood-supply will be necessary to produce congestion or inflammation of the structure, and such is really the case; and it is because of this that people who have what is called an irritable mucous membrane are so susceptible of cold. ”

“ All mechanical obstructions to the free transit of blood through the heart, lungs, or liver are followed by the same results. A free secretion of mucus into the stomach is one of the most commonly recognized. It is often vomited in large quantities. This alkaline mucus, while it dilutes the digestive juices of the stomach, furnishes favorable conditions for the development of low micro-organisms, which contribute to the fermentative process. We may not duly estimate the effects of these organisms on a mucous membrane softened by long-continued passive hyperæmia. ”

“ The mucous membranes, by the continual secretion of which they are the seat, perform a principal part in the animal economy. They are to be regarded as one of the grand emunctories, by which the residue of the nutriment constantly escapes from the body ”

“ Besides the three strata, which we have just mentioned, the mucous membranes present in their structure a great number of glands and blood vessels. The mucous glands exist in all membranes which bear that appellation: they are situate under their chorion, and even in its substance: they continually discharge, through imperceptible orifices, a mucilaginous fluid, which lubricates their free surface, and defends it from the impression of the bodies with which it is in contact, at the same time that it facilitates the passage of those substances. ”

“ The main passage from the lungs to the outer air is the trachea or windpipe, a tube formed of from sixteen to twenty rings of cartilage, united by tendons and muscular fibres, and lined with mucous membrane. ”

“ I think, that from what occurs in the intestines we cannot infer what takes place in the pituitary and palatine membranes, &c.; because, although analogous, [90] their organization may be different. In these parts we cannot examine the venous blood returning from them, as in the intestines: but, (1) If we consider, that in animals, which have for some time respired oxygen gas, the mucous membrane of the fauces does not exhibit any increase of redness ”

“ It is very difficult to point out with precision the character of the tonic powers of mucous membranes, because, being almost in every part united to a muscular layer, we can hardly distinguish what belongs to the tonicity of the one from what depends upon the irritability of the other; or otherwise, if the mucous membranes be isolated, as in the nostrils, yet their attachment renders the phenomena of their tonic powers very obscure. ”

“ For, as we have said, these glands are always subjacent to the membrane, and [42] are consequently separated by it from the irritating bodies. It appears that the above fact belongs to a general modification of the glandular sensibility, which is susceptible of being put into action by every irritation upon the extremities of the excretory ducts, which will be proved by the following considerations: (1) The presence of food in the mouth produces a more abundant flow of saliva. ”

“ I have called the texture within the ear mucous, though all anatomists call the membrane of the cavities of this organ periosteum. In fact, 1st, we see it evidently continued with the pituitary membrane, by means of the elongation of the Eustachian tube. 2d. We find it constantly moistened by a mucous fluid which this canal serves to convey out, a character foreign to the periosteum, which, like the fibrous membranes, always adheres by both its surfaces. 3d. No fibre can be distinguished in it. ”