Lymph nodes

Lymph nodes [nodi lymphatici (PNA), lymphonodi (PNA, JNA), lymphoglandulae (BNA)] - pinkish-grey soft education round shape, the diameter from 1 to 20 mm, located along the lymphatic vessels. Lymphatic vessels (see) body before falling into one of the major lymphatic ducts usually interrupted by at least one Liter. However, some of the lymph vessels of the liver, thyroid, esophagus and other bodies can directly fall into large lymph ducts, without interruption in the nodes. In humans, there are 460 lymph nodes. In embryo, human L. W. once formed the basic lymphatic vessels. Most early L. W. developing in the sphere jugular and ilio-inguinal lymph bags, in areas where the latter is replaced by connective tissue.
Lymph node (Fig. 1 and 2) has on the one hand impression - gate (hilus). In this place it includes the arteries and nerves, and come veins and lymphatic vessels carrying (vasa efferentia). Bringing lymphatic vessels (vasa afferentia) to HP. with its convex side. L. W. covered in a dense connective tissue capsule, rich in collagen fibers, containing a number of elastic fibers and smooth muscle cells. Inside of the capsule radialno thin trabeculae. In the context of L. W. clearly darker cortical substance (cortex) and lighter brain (medulla).

Fig. 1. The structure of lymph node: 1 - generating lymphatic vessels; 2 - capsule; 3 - trabeculae; 4 - efferent lymphatic vessels; 5 - end-sinus; 6 - nakotne cords; 7 - intermediate sinuses; 8 - secondary nodules; 9 - regional sinus.
Fig. 2. General view of the lymph node person (Bergmann).

Reticular fabric with trabeculae is stroma lymph node. Cortical substance consists of follicles (folliculi lymphatici), most of which are characterized by the presence of bright Central areas, surrounded by peripheral area with a large content of lymphoid cells. These lymphoid nodules called secondary, unlike primary deprived of such centres. Bright Central areas are places neoplasms of lymphocytes (see) and are called centers of reproduction. From follicles inside the site depart strands, called maketime cords and consists of the same cell as the follicles. Between the capsule and trabeculae on the one hand, the follicles and maketime cords on the other are space, called sinuses. There are regional sinus between the capsule and the follicles; intermediate sinuses between follicles, maketime cords and trabeculae and end, or Central, sinus in the field gate site. Makunia cords, trabeculae and intermediate sinuses are the medulla site.
The blood supply L. W. is arteries, come through the gate. They wetas, pass through the trabeculae, penetrating then makunia cords and forming a capillary network around the follicle. Vienna accompany artery or follow yourself, going out in the field gate.
Nerves L. W. follow along the blood vessels and end kostykovichi endings. In L. W. there was also a polyvalent nerves ending on vessels and lymphoid tissue.
In children, number of lymph nodes more, they are closer to each other and relatively larger. With age capsule L. W. thickens, correlations of cerebral cortical substance, the amount of the sinuses. Part of HP. it may be replaced by connective and fat.
Functional significance L. W. is determined by their participation in the processes of blood (see) and protective reactions of the organism (this is confirmed by such demonstrative experiment: in animals from birth was brought up in sterile conditions, L. y. almost do not develop). Flowing through L. y., lymph (see) is enriched by lymphocytes that come into it from the follicles and makalnyh cords. Lymph nodes are active biological and mechanical filter. This property L. W. due to the phagocytic activity of their reticuloendothelial cells. Mechanical filtration is carried out thanks to its original architecture of the ways in which the lymph passes through the site. Plasma cells available in L.U., produce antibodies.
Lymph nodes are located in places where they are exposed muscles in contact with pulsating arterial trunks, etc., It suggests the participation of L. W. in promoting lymph by sucking and pushing it. Due to significant compliance L. W. can adjust the number of lymph, flowing from the organ or area of the body. Especially important is the participation of L. W. in the regulation of lymphatic drainage thoracic and abdominal cavities. L. W. are headers of lymph from private bodies operating in this field. The same L. W. can receive lymph from several organs and, on the contrary, the authority may enter multiple outlet lymphatic vessels, leading to various lymph nodes. The group's L. U. usually lie in the permanent, take lymph from certain areas or organs and are called regional L. W.
Some animals and humans in the thoracic and abdominal cavities are small in size, with dark red nodes, called the haemolymph nodes. Outside they are covered with the capsule, which inside depart trabeculae. The trabeculae in the node from the capsules are artery accompanied veins. The basis of nodes is reticular fabric, the follicles are no special orientation, sinuses are filled with blood. The origin and function of haemolymph nodes are not sufficiently clarified.
Radio isotopic studies of the lymph nodes - see Lymphatic vessels. X-ray L. y.- see Lymphography.