STRUCTURE OF LYMPH GLANDS 



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or lymph sinus (Fig. 597). Running across it are a number of finer trabeculse of retiform con- 

 nective tissue, the fibers of which are, for the most part, covered by ramifying cells. 



On account of the peculiar arrangement of the frame-work of the organ, the gland pulp in the 

 cortical portion is disposed in the form of nodules, and in the medullary part in the form of rounded 

 cords. It consists of ordinary lymphoid tissue (Fig. 598), being made up of a delicate net-work 

 of retiform tissue, which is continuous with that in the lymph paths, but marked off from it 

 by a closer reticulation; it is probable, moreover, that the reticular tissue of the gland pulp and 

 the lymph paths is continuous with that of the trabeculse, and ultimately with that of the capsule 

 of the gland. In its meshes, in the nodules and cords of lymphoid tissue, are closely packed 

 lymph corpuscles. The gland pulp is traversed by a dense plexus of capillary bloodvessels. 

 The nodules or follicles in the cortical portion of the gland frequently show, in their centers, 

 areas where karyokinetic figures indicate a division of the lymph corpuscles. These areas are 

 termed germ centers. The cells composing them have more abundant protoplasm than the 

 peripheral cells. 



The afferent vessels, as stated above, enter at all parts of the periphery of the gland, and after 

 branching and forming a dense plexus in the substance of the capsule, open into the lymph sinuses 

 of the cortical part. In doing this they lose all their coats except their endothelial lining, which 

 is continuous with a layer of similar cells lining the lymph paths. In like manner the efferent 

 vessel commences from the lymph sinuses of the medullary portion. The stream of lymph carried 

 to the gland by the afferent vessels thus passes through the plexus in the capsule to the lymph 





FIG. 598. Lymph gland tissue. Highly magnified, a, Trabeculse. b. Small artery in substance of same, 

 c. Lymph paths, d. Lympji corpuscles, e. Capillary plexus. 



paths of the cortical portion, where it is exposed to the action of the gland pulp; flowing through 

 these it enters the paths or sinuses of the medullary portion, and finally emerges from the hilus 

 by means of the efferent vessel. The stream of lymph in its passage through the lymph sinuses 

 is much retarded by the presence of the reticulum, hence morphological elements, either normal 

 or morbid, are easily arrested and deposited in the sinuses. Many lymph corpuscles pass with 

 the efferent lymph stream to join the general blood stream. The arteries of the gland enter 

 at the hilus, and either go at once to the gland pulp, to break up into a capillary plexus, or else 

 run along the trabeculse, partly to supply them and partly running across the lymph paths, 

 to assist in forming the capillary plexus of the gland pulp. This plexus traverses the lymphoid 

 tissue, but does not enter into the lymph sinuses. From it the veins commence and emerge 

 from the organ at the same place as that at which the arteries enter. 



The lymphatic vessels are arranged into a superficial and a deep set. On the 

 surface of the body the superficial lymphatic vessels are placed immediately 

 beneath the integument, accompanying the superficial veins; they join the deep 

 lymphatic vessels in certain situations by perforating the deep fascia. In the 

 interior of the body they lie in the submucous areolar tissue, throughout the whole 

 length of the digestive, respiratory, and genito-urinary tracts; and in the- subserous 

 tissue of the thoracic and abdominal walls. Plexiform networks of minute lym- 

 phatic vessels are found interspersed among the proper elements and bloodvessels 

 of the several tissues; the vessels composing the net- work, as well as the meshes 

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