Lymph node

“ Vascular lesions can be seen in the heart, kidney, lung, liver, nervous system, skeletal muscle, and synovial membranes. Cellular response to infection by E. rhusiopathiae consists predominantly of mononuclear leukocytes and macrophages. Neutrophils may appear but do not predominate. Purulent lesions are not characteristic of E. rhusiopathiae infection.
Affected lymph nodes usually show acute hyperplastic lymphadenitis, with hyperemia and hemorrhage. In some nodes there may be evidence of thrombosis and necrosis of small blood vessels and capillaries. ”

“ These capillaries then unite to form the lymph vessels and these then convey the lymph to the subclavian veins. The lymph is a colorless fluid and contains numerous blood corpuscles known as lymphocytes. But in those lymphatic vessels, which have their origin in the walls of the small intestines, the lymph, especially during digestion, contains a great amount of fat, so that it has a milky appearance, and for this reason the lymphatics of this region, have been termed lacteals. There are two main lymphatic trunks, the one on the left side is called the thoracic duct. ”

“ But when I come to examine the distribution of the lymphatics in the different situations in which elephantiasis occurs, I find a difficulty, from a mechanical point of view alone, of explaining how the obstruction which is necessary to produce a complete lymph stasis can occur. Looking again at the illustration of the superficial lymphatics of the leg, at what point in the limb can a single worm be situated so that the lymph-stream would carry the ova so as to obstruct the whole of the superficial inguinal glands? ”

“ Whatever enters the lymph may, if small enough, pass through the glands and be swept along with the current, but the structure of the gland is, in a mechanical sense, a filtering apparatus, interrupting the free current of the fluid and retaining the coarser particles. The lymph in passing through the glands derives constituents not previously possessed, but, nevertheless, the retention of elements which for a time might arrest the dissemination of hurtful material may eventually convert the gland into a new source of infection. ”

“ A distinguished pathologist at Vienna, Professor Paltauf, who was the coroner's physician of the city and had a large number of these sudden deaths to investigate, found that in most of the cases one abnormal condition was constantly present. This consisted in an enlargement of the lymph glands all over the body. The lymph glands in the neck were involved, also the tonsils and lymphoid tissue at the back of the throat, the series of lymph glands in the groin, and, finally, there was a hypertrophy of the lymphoid tissue that occurs all along the intestinal tract. ”

“ Most people who are not critically ill need to walk at least 200 yards twice a day, with assistance if necessary, if only to move the lymph through the system. The lymphatic system is a network of ducts and nodes which are distributed throughout the body, with high concentrations of nodes in the neck, chest, arm pits, and groin. ”

“ In nearly every tissue and organ of the body there is a marvelous network of vessels, called the lymphatics. These are busily at work taking up and making over waste fluids or surplus materials derived from the blood and tissues generally. The lymphatics seem to spring from the parts in which they are found, like the rootlets of a plant in the soil. They carry a turbid, slightly yellowish fluid, called lymph, very much like blood without the red corpuscles. The lymph is carried to the lymphatic glands where it undergoes certain changes to fit it for entering the blood. ”

“ The collection of the lymph from organs is much more difficult to effect, and hence has not, to the present, been so extensively studied. We will consider first variations in the amount of the thoracic duct lymph. Lymph is always flowing along the thoracic duct, and if the body is at rest, it has been shown that this lymph is coming practically entirely from the intestines and liver, chiefly, moreover, from the liver. ”

“ Along their course the lymphatics frequently pass through glands,—hard, pinkish bodies of all sizes, from that of a hemp seed to an almond. These glands are often enlarged by disease, and then are easily felt.
The Lymph, which circulates through the lymphatics like blood through the veins, is a thin, colorless liquid, very like the serum. This fluid, probably in great measure an overflow from the blood vessels, is gathered up by the lymphatics, undergoes in the glands some process of preparation not well understood, and is then returned to the circulation. ”

“ Under this condition of an increased excitement in the peritoneal or other serous membrane, coagulable lymph is discharged into its cellular tissue, and a thickening of it takes place; until at length the operation of paracentesis, which in the early stage of the disease was attended with only inconsiderable inconvenience, becomes an adequate cause of a still higher inflammation, which terminates perhaps in suppuration; and, in the post mortem examination the serous fluid is found so mixed with coagulable lymph, and purulent matter, as to give a whey or milk-like appearance to the mass. ”

“ Not only is deglutition difficult, but it is difficult to open the mouth sufficiently to inspect the fauces, and attempts to do so cause much pain. The lymphatic glands, which lie in the inflamed area and participate in the inflammation, are greatly enlarged by hyperplasia, the round granular lymph-cells multiplying so abundantly that the glands increase to many times their normal size. Most of the tumefaction is, however, due to extension of the inflammation to the connective tissue of the neck. ”

“ Sometimes none can be found; rarely are they abundant. In the same case they are sometimes present, sometimes absent. Centrifuging the blood is not of much assistance. Dutton and Todd have emphasized the value of lymphatic-gland puncture and examination of the aspirated lymph, particularly in the earlier stages of the disease when the glands are soft and before they have become sclerosed; then the trypanosomes are fairly abundant in the lymph. An ordinary hypodermic syringe suffices to aspirate a sufficiency of lymph. ”

“ For my own part, I am of opinion that the small-pox is a disease of the lymphatic system only, and my opinion seems to be confirmed by the impossibility of communicating [Pg 76] the infection by inoculating with the blood. Be this as it may, it is indisputably true, that the crude lymph is sufficient to give the infection, and that there is no necessity to draw blood at the time of incision. Add to this, the frequent tumour of the lymphatic glands in the axilla soon after the operation. ”

“ If it retains the capacity of growth or of stimulating a like growth, there results a more or less complete transformation of the gland into a morbid tissue like that from which the fragments came. Adjoining lymph-glands may become infected from the first, until eventually an entire series becomes more or less completely transformed into morbid growths. A like invasion of the lymphatic glands may take place through a continuous extension along the lymph-vessels ”

“ The glands act as filters, arresting not only inert substances, such as blood pigment circulating in the lymph, but also living elements, such as cancer cells or bacteria. As it passes through a gland the lymph is brought into intimate contact with the leucocytes, and in bacterial infections there is always a struggle between the organisms and the leucocytes, so that the glands may be looked upon as an important line of defence, retarding or preventing the passage of bacteria and their products into the general circulation. ”

“ By the formation of false membrane, the symptoms may be so much increased as to cause speedy dissolution; but in many cases the patient’s strength is not altogether exhausted, and the extraneous substance by its irritation causes frequent and violent attempts to expectorate, by which the lymph is not unfrequently expelled either entire or in irregular portions; the relief thereby afforded, though considerable, is in general temporary, for lymph is speedily redeposited, or there is a profuse muco-purulent expectoration, and the patient succumbs. ”

“ Many undergo a fatty degeneration, and as they lie in lymph-spaces their conversion into an emulsion permits a removal of the mechanical obstruction to the flow of lymph through the spaces in which they were accumulated. The red blood-corpuscles are destroyed, their pigment being dissolved by the surrounding fluid and removed in the course of the circulation and excretions, or it becomes transformed into granules or crystals, which may remain in the place of their formation, or be transferred, within amoeboid cells, to remote parts of the body. ”

“ Like blood it clots, but clots badly, only forming a soft clot which quickly contracts. The lymph collected from a lymphatic before it has passed through a lymph gland contains a few leucocytes, and though the number of lymphocytes is greater in the lymph after it has flowed through a gland it is never very great. In normal states there are no red blood corpuscles.
The total solids amount to 3.6 to 5.7%, the variations depending upon the amount of protein present. The lymph during hunger contains only a minute quantity of fat. ”

“ Under the influence of the muscular system comes not only the blood but the lymph. The lymphatics form a subsidiary system of small valved vessels, and drain the tissues of the excess of lymph, which transudes from the capillaries of the organs during functional activity, or in consequence of venous obstruction. The larger lymphatics open into the veins at the root of the neck. It is chiefly by the compressive action of the skeletal and visceral muscles, and the aspirating action of the respiratory pump, that the lymph is propelled onwards. ”

“ But in some instances, when no lymph is previously effused, and no cyst is formed, the matter is not confined, but pervades the cellular substance extensively, and is generally followed by more or less sloughing of that tissue, and by great constitutional disturbance. This most frequently occurs in patients of a debilitated habit, in whom the incited action has been so slight as not to cause the effusion of lymph, by which nature usually sets bounds to the suppurating process. ”

“ The lymphatics far exceed the veins in number and perform a function similar to the veins, gathering waste material from the tissues, also the digested food called chyle, from the stomach and intestines. The lymphatic vessels, also the lacteals which absorb the chyle, all pass through glands, which are extremely numerous, where certain deleterious substances are extracted from the lymph before it is emptied into the blood stream. ”

“ Successive additions of cells continue to block these channels, and finally the passage of lymph through the gland becomes impossible, and then begins that secondary increase of the lymph-cells in the gland resulting from their inflammatory proliferation.
"In scrofulous inflammation," say Cornil and Ranvier,7 "there is a remarkable tendency to permanent infiltration of the affected tissue. In simple inflammation (i.e. inflammation in non-scrofulous persons) the infiltration is a temporary condition which terminates in suppuration, in organization, or in resolution." ”

“ An accessory cause can sometimes be observed where a local irritation gives rise to swelling of the adjacent lymphatic glands and this goes on to distinct lymphadenoma.
Lesions in the Lymph Glands. The hyperplasia may affect but a single group of glands, more commonly a number of groups, and often nearly all. In one case only of leukæmia in the lower animals, a dog, has Nocard failed to find the lymph glands affected. In the horse he has found the sublumbar glands alone weighing 14.5 kilogrammes, 11 k. and 8 k. They compressed the posterior aorta and vena cava and had caused extensive ascites. ”

“ The inguinal glands are early involved, and after a time the internal lymph glands follow. The enlargements are at first painless, but in the later stages symptoms are caused by pressure on the surrounding organs, and when the disease starts in the deeper structures the first symptoms may be pain in the chest and cough, pain in the abdomen, pain and oedema in the legs. The glands may increase until they are as large as eggs, and later may become firmly adherent one to another, forming large lobulated tumours. ”

“ Termination of inflammation.—Like congestion, inflammation may terminate by resolution. In this case the exuded lymph undergoes chemical change, and the products are absorbed and carried off by the blood vessels and lymphatics, to be thrown out of the body by the kidneys, liver, the glands of the skin, and the other excretory organs. The cells, which have wandered into the neighboring tissues from the blood vessels, gradually disappear or become transformed into fixed cells. Those which are the result of the tissue cells, wakened into active life, follow the same course. ”

“ The frequent infection of the pharyngeal, bronchial, mediastinal and mesenteric lymph glands has been already sufficiently noticed, and if the other groups suffer less it is mainly because the tissues from which they derive their lymph are less frequently infected. An intimate knowledge of the different groups of lymph glands is a most essential prerequisite to the diagnosis of tuberculosis in life, and no less to a satisfactory post mortem examination. ”

“ The study of their development shows that they grow into the tissue as a closed system of minute tubes, which indicates that in all probability they remain permanently closed. If we trace the lymphatic vessels towards the thorax we find that in some part of their course they terminate in structures known as lymphatic glands. From these again fresh lymphatic vessels arise which carry the fluid towards the main lymph-vessel, the thoracic duct. ”