CHAPTER II. 



THE LYMPH-NODES. 



General Characteristics of the Lymph-Nodes. 



IT is well, in studying the lesions of the lymph-nodes, to remember that they are 

 structures so placed in the course of the lymph- vessels that the lymph, in flowing 

 toward the larger central trunks, passes through them, undergoing a sort, of filtration 

 as it percolates through the trabecute of the lymph sinuses. If this fact be borne in 

 mind the lesions of the lymph-nodes, which are in the majority of cases secondary, are 

 much more readily understood. Particles of pigment, cells from malignant tumors, 

 fragments of dead or disintegrating cells either free or within phagocytes, red blood 

 cells, bacteria, etc., which in any way get into the lymph-vessels, are carried along 

 until a lymph -node is reached, and here they are, in part at least, deposited among the 

 trabeculse of the sinuses, or are taken up by phagocytic cells, while the lymph passes on 

 and out of the efferent vessels. Soluble toxic substances also are carried into the lymph 

 nodes, often inciting marked and significant alterations. 1 



What is called lymphatic tissue embraces not only the so-called lymph-glands and 

 the less complex but still well-defined structures found in the stomach, intestines, ton- 

 sils, and elsewhere, and called lymph follicles, but als the less well-defined, irregular 

 masses of tissue resembling that of lymph follicles, which, as Arnold has shown (Vir- 

 . chow's Archie, Bd. Ixxx., p. 315; Bd. Ixxxii., p. 394; Bd. Ixxxiii., p. 289; Bd. Ixxxvii., 

 p. 114), is widely disseminated in variable amounts in different parts of the body; in 

 the lungs, beneath the pleura, in the interlobular septa, and elsewhere; in the liver, 

 kidneys, etc. Although the txact nature of these more diffuse masses of lymphatic 

 tissue is too little understood, as indeed is that of the lymph follicles and glands them- 

 selves, there is reason to believe that they are analogous structures and prone to be 

 affected by similar deleterious agencies. It seems better, in view of the fact that the 

 so-called lymph-glands are not glands at all, in the ordinary sense of the word, to call 

 them lymph-nodes, and the smaller masses of lymphatic tissue scattered through various 

 parts of the body lymph-nodules instead of "lymph follicles." 



ATROPHY. 



Atrophy is a very regular occurrence in old age. In this condition 

 the nodes are small, hard, and, unless pigmeuted, light in color. Micro- 

 scopical examination shows a marked diminution in the number of par- 

 enchyma cells, while the reticulnm and the capsule and trabeculae may be 

 thickened. There may be an accumulation of fat around the node in 

 senile atrophy. 



It should be remembered, in this connection, that the lymph -nodes, 

 as well as the lymphatic tissue in general, in children are more volumi- 

 nous than in adults. 



1 For a study of bacteria in normal lymph-nodes see Kalble, Munch, med. Wochen- 

 schr., 1899, p. 622. 



