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*Pathology of the Lymph Nodes*

Updated on December 23, 2015

Lymphatic System

The lymphatic system can be thought of as a drainage system needed because, as blood circulates through the body, blood plasma leaks into tissues through the thin walls of the capillaries. The portion of blood plasma that escapes is called interstitial or extracellular fluid, and it contains oxygen, glucose, amino acids, and other nutrients needed by tissue cells.The lymphatic system removes this fluid and these materials from tissues, returning them via the lymphatic vessels to the bloodstream, and thus prevents a fluid imbalance that would result in the organism’s death.

The most interesting thing about the Lymphatic system is that in addition to serving as a drainage network, the lymphatic system helps protect the body against infection by producing white blood cells called lymphocytes, which help rid the body of disease-causing microorganisms. The organs and tissues of the lymphatic system are the major sites of production, differentiation, and proliferation of two types of lymphocytes the T-lymphocytes and B lymphocytes, also called T cells and B cells. Although lymphocytes are distributed throughout the body, it is within the lymphatic system that they are most likely to encounter foreign microorganisms. The second most interesting thing about the Lymphatic system is the absorption of fats and fat-soluble vitamins from the digestive system and the subsequent transport of these substances to the venous circulation. The mucosa that lines the small intestine is covered with fingerlike projections called villi. There are blood capillaries and special lymph capillaries, called lacteals, in the center of each villus. The lymphatic system begins as a series of sacs 108 at the points of junction of certain of the embryonic veins. These lymph-sacs are developed by the confluence of numerous venous capillaries, which at first lose their connections with the venous system, but subsequently, on the formation of the sacs, regain them.



Lymphatic System

Breasts are made up of fat, supportive (connective) tissue and glandular tissue containing lobes. The lobes (milk glands) are where breast milk is made. They connect to the nipple by a network of fine tubes called milk ducts. It’s common for a woman’s breasts to be a different size or shape from each other. They also feel different at different times of the month. For example, just before a woman’s period, her breasts may feel lumpy. As a woman gets older, her breasts may become smaller and feel softer.

Sometimes, cancer can spread through the lymphatic system. If the cancer cells spread outside the breast, they are most likely to go to lymph nodes in the armpit. You will usually have tests on the lymph nodes to look for cancer cells. There are also lymph nodes near the breastbone and behind the collarbone.

As lymph moves from its origin in the tissue spaces toward the thoracic or right lymphatic ducts and then into the venous blood, it is filtered by way of moving through lymph nodes, which are located in clusters along the pathway of lymphatic vessels. Some of these nodes may be as small as a pinhead, and others may be as large as a lima bean. With the exception of a comparatively few single nodes, most lymph nodes occur in groups or clusters in certain areas. The structure of the lymph nodes makes it possible for them to perform two important immune functions: defense and white blood cell formation. Lymph nodes are lymphoid organs because they contain lymphoid tissue, which is a mass of developing lymphocytes and related cells. Lymphoid organs such as lymph nodes, tonsils, thymus, and spleen are important structural components of the immune system because they provide immune defense and development of immune cells.

Although small in size, the thymus plays a central and critical role in the body’s vital immunity mechanism. First, it is a source of lymphocytes before birth and is then especially important in the “maturation” or development of a type of lymphocyte that then leaves the thymus and circulates to the spleen, tonsils, lymph nodes, and other lymphoid tissues. These T-lymphocytes, or T cells, are critical to the functioning of the immune system and are discussed later. A group of hormones secreted by the thymus, called thymosins influences the development of T cells. The thymus appears to complete much of its work early in childhood, reaching its maximum size at puberty. The thymus tissue is then gradually replaced by fat and connective tissue, a process called involution. By age 60, the thymus is about half its maximum size and is virtually gone by age 80 or so.

Lymph Nodes

Because these glands are probably not swollen and because they are likely to be dangerous even if they are there isn't necessarily a specific cure that addresses these concerns directly. There has been some studies that show anxiety can lead to swollen lymph nodes.

The lymphoid lobule is the basic anatomical and functional unit of the lymph node. The smallest lymph nodes may contain only a few lobules or even just one, while large lymph nodes may contain a great many. Lymphoid lobules are arranged side-by-side and radiate capsad from the hilus. Each lobule has a bulbous apex and a base of slender cords that gives it a medusoid appearance. Lobules are anchored in the hilus by their vascular roots but they are otherwise separated from the capsule by the subcapsular sinus. Stimulated T lymphocytes proliferate in the paracortex and enlarge it but do not produce structures analogous to germinal centers. The peripheral DCU and the interfollicular cortex also serve as transit corridors for lymphocytes migrating to and from the B and T cell areas. Plasma cell precursors produced by B cell proliferation migrate to the medullary cords where they mature and secrete antibodies that are released into the lymph

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Dendritic cells (DCs) are potent APCs that collect and process antigens from tissues, carry them to lymph nodes and present them to T-cells to initiate primary immune responses. DCs originate in the bone marrow and then spread to all the tissues of the body except the brain, eyes and testes. There are several different populations of DCs, including the Langerhans cells of the dermis and a recently described population in the intestine that endocytizes apoptotic cells. In the tissues, immature DCs sample the local antigens and then migrate to lymphatic vessels to be transported in the lymph to the draining lymph node.

Lymph Nodes

Removal Of The Lymph Nodes

Lymphadenectomy is surgery to remove the lymph nodes. This surgery is done to see if cancer has spread to a lymph node. Some lymph nodes are located near the surface of the body, while others are deep in the abdomen or around organs, such as the heart or liver. With this type of surgery anesthesia is used. Then an incision is made in the skin over the lymph nodes to be removed. The type and also the depth of the incision varies depending upon the location of these lymph nodes. The lymph nodes are removed along with nearby lymphatic tissue and some underlying soft tissue.

It is important to keep your system healthy so that in general you are healthy yourself. Keeping yourself hydrated, refraining from smoking, drinking and use of recreational drugs is the best way. If you have any feeling that your Lymph Nodes might be swollen please visit your MD so that they can provide a great care.

Thanks, M

Lymphatic System

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© 2015 Mahsa S

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    • mahsa setareh profile image
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      Mahsa S 19 months ago

      Thank you I'm glad that this article was helpful for you

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      Maya 19 months ago

      Thanks, helpful article.