Alveolus

“ First, other congeries of glands occupy but a particular part of the system, or constitute a particular organ, as the liver, or kidneys; but those glands, which secrete the mucus, and perspirable matter, which are called capillaries, are of very great extent; they receive the blood from the arteries, separate from it the mucus, which lines every cell, and covers every cavity of body; and the perspirable matter, which softens and lubricates the whole surface of the skin, and the more extensive surface of the air-vessels, which compose the lungs. ”

“ The pathological process in the majority of cases in the adult is interstitial new formation, very often evoked by antecedent catarrhal inflammation. At first small spindle-shaped and round cells appear and develop into connective tissue, among the fibres of which blood-vessels are freely produced; the septa of the alveoli are thickened and the alveoli themselves compressed. In any morbid process in the lungs, such as tubercle, sarcoma, or cancer, the alveoli act as the inter-fascicular spaces of the connective tissue. ”

“ Extensive effusions of serum, lymph, and pus, mixed in different proportions, will take place in the serous cavities of the body, and become infiltrated in the cellular membrane, accompanied with very slight indications of inflammatory action. The colouring matter of the blood will also sometimes become effused with its other parts; but when this is the case, the blood will be found to have lost its coagulating power: in this respect presenting a direct contrast to the effusion from a healthy wounded vessel. ”

“ The Alveoli.—The alveoli, or air cells, are the small divisions of the infundibula (Fig. 36) . They are each about one one-hundredth of an inch (1/4 mm.) in diameter, being formed by the infolding of the infundibular wall. This wall, which has for its framework a thin layer of elastic connective tissue, supports a dense network of capillaries (Fig. 37) , and is lined by a single layer of cells placed edge to edge. By this arrangement the air within the alveoli is brought very near a large surface of blood, and the exchange of gases between the air and the blood is made possible. ”

“ In the middle of the day, there was a liquid greyish white evacuation, resembling pus in its odour, consistence, and appearance, mixed with some clots of putrified blood. Death occurred during the following night.
Post-mortem appearances. The mucous membrane of the eyes, nose, and mouth, was red or violet, and covered by a very abundant thick mucus. The lungs were of a dark colour, with some black patches, but still crepitant. The left ventricle of the heart presented several brown stains, resembling ecchymoses, which penetrated into its tissue. ”

“ The epithelium lining the alveolar walls is the seat of cloudy swelling, becomes less closely attached, and undergoes proliferation, with the formation of large epithelial elements. The morbid product filling the alveoli is composed in varying proportions of these latter elements, of the richly cellular bronchial secretion which has been sucked in from the bronchioles, of leucocytes, and much more rarely of red blood-corpuscles which have escaped from the pulmonary capillaries, and finally of fibrillated exudation. ”

“ With the Production of new Vessels by internal Membranes or Glands, without Fever.
Where inflammation is produced in a small part, which has not great natural sensibility, the additional sensation does not produce an increased action of the arterial system; that is, the associated motions which are employed in the circulation of the blood, those for instance of the heart, arteries, glands, capillaries, and their correspondent veins, are not thrown into increased action by so small an addition of the sensorial power of sensation. ”

“ The capillaries widen into small veins, the veins into larger ones, and finally into the great hollow veins, the superior and inferior vena cava, which bring back the dark blood to the right side of the heart, to start again on its journey to the lungs for purification. The processes which go on in the lesser and greater circulation are, in a manner, the reverse of one another.
The skin acts as an excretory organ, much in the same way as the lungs and kidneys do ”

“ In these mild attacks, which occur frequently in adults, the part affected may be the base of the lung, but more commonly it is the root, the apex, or the lower anterior portion of the upper lobe. The anatomical condition is probably one of congestion, with extension of catarrhal inflammation into the alveoli without any preceding collapse, and with a varying degree of implication of the walls of the vesicles and of epithelial accumulation in the alveoli, though the process may not always go on to the production of fully-formed pneumonic nodules, such as above described. ”

“ The alterations in an inflamed tissue are first those of congestion, distention of the blood vessels, and exudation of the fluid of the blood into the surrounding fibers, with, however, a more nearly complete stagnation of the blood; fibrin, or lymph, a plastic substance, is thrown out as well, and the cells, which we have seen to be living organisms in themselves, no longer carried in the current of the blood, migrate from the vessels and, finding proper nutriment, proliferate or multiply with greater or lesser rapidity. ”

“ Human blood, as is well known, shows the buffy coat in some states of inflammation. But it may also occur in anæmia. [2] And it may well make our profession humble to reflect that in days within living memory buffing of the clot was regarded as an indication for further withdrawal of the vital fluid by venesection.
To return from this digression: adhesiveness of the corpuscles, both red and white, was seen in the vessels of an irritated area of the frog's web, as in blood outside the body. ”

“ The pure and impure blood are never mingled, and all the blood has to pass through the lungs and be oxygenated every time it makes the complete circuit. This perfect circulation, with aerial respiration, produces more rapid chemical changes in the blood and tissues, and consequently the higher temperature of the "warm-blooded" animals. In the embryonic stages of the heart, the septum dividing the auricles is slowly formed, and an aperture exists for a time, called the foramen ovale. Cases rarely occur of human subjects in which the opening persists. ”

“ Sinus occipitalis externa The trunk of the internal facial vein receives the blood of the internal mandibular vein. The internal mandibular vein emerges from the alveolar canal of the inferior jaw bone and receives branches from the muscles of mastication.
The vena retis mirabilis temporalis passes out of the eye cavity and lies between the internal facial vein and the external facial vein, and passes around the os quadratum and the os pterygoideum. It receives veins from the outer ear region, lacrimal gland, eyelids, and the spheno-temporalis. ”

“ The colour of this fluid in the arteries is of a florid hue; but somewhat darker in the veins, except in those of the lungs, in which it is of a lighter cast. When exposed to the open air, the blood gradually separates into two parts, namely, the serum, or a yellowish, sometimes greenish fluid, and the crassamentum, or cake, which resembles a red mass swimming distinctly on the top. The latter contracts greatly in its dimensions, and increases in solidity; properties which depend on the state of the individual at the time when the blood is drawn. ”

“ The veins of elderly people become turgid or distended with blood, and stand prominent on the skin; for as these do not possess the elasticity of the arteries, they become distended with accumulation of blood; when the heart by its lessened excitability does not contract sufficiently forcibly, or frequently, to receive, as fast as usual, the returning blood; and their apparent prominence on the skin is occasioned by the deficient secretion of fat or mucus in the cellular membrane; and also to the contraction and coalescence and consequent less bulk of many capillary arteries. ”

“ It has been already shown that the blood, when in a natural condition, has a tendency to coagulate around pus, and, probably, many other fluids, even out of the body (Experiments i, v) , [Pg 8] and that this property is exercised in a still more remarkable manner in the living vessels (see Experiments vii, viii) . Foreign matter, even after it has got into the veins, may then, by the same means, be prevented from proceeding farther towards the centre of circulation. The process that takes place under such circumstances, is strictly analogous to union by the first intention. ”

“ The fugitive paleness, which accompanies the coldness of the extremities, is owing to a less quantity of blood passing through the capillaries of the skin in a given time; where the absorbent power of the veins is at the same time much diminished, a part of the blood lingers at their junction with the capillary arteries, and a bluish tinge is mixed with the paleness; as is seen in the loose skin under the eye-lids, and is always a mark of temporary debility. ”

“ Such, for instance, is the preservation in the adult of the foramen ovale between the auricles of the heart, or of the open ductus arteriosus by which blood of the pulmonary and body circulation may mingle. In case of the veins also an arrangement of vessels is often found in the adult which is due to the persistence of a truly embryonic condition. ”

“ The arteries fork and branch out in every direction, until they terminate in millions of little veins smaller than the finest hairs, and these running together make bigger veins, through which the blood is carried to the lungs. In the veins it flows steadily, because the capillary veins, the ones like hairs, are so small that the spurts can't be felt beyond them. The blood in the veins is thick and dark, because it has taken up all the impurities from the system ”

“ When, during life, one tissue is separated from another, as the periosteum from the bone, or the cuticle from the skin, or the mutual cohesion between different tissues is sensibly weakened, we find it to be owing to the intervention of serous fluid which does not belong to their healthy state; and this, together with increased vascularity, or redness and heat, and pain, is enough to bespeak the presence of inflammation. ”

“ The disease will appear at once in various spots, which will become rapidly disorganized, while the surrounding textures will remain unaltered, either in structure or colour. The appearances observed upon dissection will vary according to the part attacked, and the stage of development in which the disease is found.
The lungs are the organs in which the successive changes may best be observed. When puriform fluid has entered the circulation, the first appearance produced in the structure of the lungs, is that of one or more congested or dilated veins [33] of very small diameter. ”

“ These glands in the hibernating animal have many more alveoli than in the feeding animal, though this, again, may have been due to the difference in age.
The lining of the roof of the mouth is essentially the same as that of the tongue. The glands are found only in the posterior region. The slight differences in the papillæ here found may easily be due to the difference in age.
The œsophagus shows the usual layers for that region. Its epithelium is partly ciliated in the anterior part. The muscularis mucosa is very scant in the anterior region. ”

“ In this group, the cells are agglutinated by the serum of all the other groups, while their serum contains no agglutinin whatever. These groups never change. They are what you might call the 'finger-prints of the blood.'
“As a baby is developed in the embryo,” Kennedy went on, “the specific agglutinability of the red cells, call agglutinogen, appears first and is usually present at birth. The specific agglutinative power of the blood-serum, called agglutinin, which is to characterize the individual through life, may be absent at birth and may not appear for some months.” ”

“ It is an organized texture containing blood vessels, glands and nerves. It is composed of several layers; the outside, called the epidermis, is not supplied with blood vessels, and is produced by the under layers.
The glands of the skin are first, those which secrete the perspiration. This is poured out to keep the temperature of the body even, also to rid the circulation of many injurious substances. Then there are glands which secrete an oily matter which aids in preserving the softness and pliability of the skin. These glands are called sebaceous glands. ”

“ The exciting cause of the inflammation in such cases appears to be conveyed by means of the contents of the vessels to the vessels themselves. But, as in post-mortem examinations, the changes produced in the vessels are much more easily recognized than the alterations in their contents, the former have of late years almost exclusively occupied the attention of pathologists. The cases in which constitutional symptoms follow inflammation of the veins, will be found to divide themselves principally into three large classes. 1. Those in which one of the larger veins has been opened. ”

“ The rosy drop of the face of some drinking people is produced like the gout described below, in consequence of an inflamed liver. In these constitutions the skin of the face being exposed to greater variation of heat and cold than the membranes of the liver, possesses more mobility than those hepatic membranes; and hence by whatever means these membranes are induced to sympathize, when this sensitive association occurs, the cutaneous vessels of the face run into greater degrees of those motions, which constitute inflammation, than previously existed in the membranes of the liver ”