Human lymphatic system
The lymphatic system of a person is a huge network of the smallest vessels, which are combined into larger, and sent to the lymph nodes. Lymphatic capillaries permeate all human tissues, as well as blood vessels. Connecting with each other, the capillaries form the smallest network.
Through it, fluid, protein substances, metabolic products, microbes, as well as foreign substances and toxins are removed from the tissues. In the lymph that fills the lymphatic system, there are cells that protect the body from invading microbes, as well as foreign substances. Together, the capillaries form vessels of different diameters. The largest lymphatic duct flows into the bloodstream.
The lymph nodes
Lymph nodes are formed by a round or oval shape with sizes ranging from 1 millimeter to 2 centimeters. The lymph node is a barrier to the spread of both infection and cancer cells. It produces lymphocytes – protective cells that are actively involved in the destruction of foreign substances and cells.
Thus, the lymph nodes are located in the elbow, axilla, knee, and inguinal region. The lymph nodes of the neck provide protection against infections and tumors of the head and organs located in the neck. A huge number of lymph nodes is located in the abdominal and chest cavity. Lymphocapillaries permeate organs as well as superficial tissues. Lymph nodes, which are located along the blood vessels, perform the same function.
Causes of lymphadenopathy
An enlarged lymph node indicates a problem in the area that the node “serves”. Most often, an increase in the lymph node is due to infection, less often it is a consequence of a tumor lesion. When purulent processes, as a rule, there is an acute lymphadenitis – inflammation of the lymph node. There is an inflammatory process due to microbes from wounds located in the service area of the lymph node.
The main manifestation is an increase in the lymph node, the appearance of pain when it is palpating. If a purulent process occurs over the lymph node, the skin may redden. If at this moment the open cavity is not opened, the lymph node membrane is broken and the pus penetrates into the surrounding tissues. There is a serious complication of lymphadenitis – phlegmon.
In children, an increase in lymph nodes in tuberculosis is one of the most characteristic manifestations of infection. Most often increases the lymph nodes of the chest cavity. Rarely marked increase in the lymph nodes of the neck (popularly called scrofula). A frequent cause of lymph node enlargement in children is cat scratch disease. The causative agent of this infection is a microbe called Bartonella. Carriers are bacteria cats. From scratches, microbes spread through the lymphatic vessels and enter lymph nodes, which grow and become painful.
Non-healing purulent cancer and an enlarged nearby lymph node should always suggest a cat scratch disease, as the cause of such a condition. In acute respiratory viral infections (ARVI) in children, an increase in several groups of lymph nodes may be observed. This is a consequence of an excessive response of the immune system to the invasion of viruses into the body. As a rule, lymph nodes in such cases increase slightly and painful when palpating.
Causes of an increase in the inguinal lymph nodes
In venereal diseases, in particular in syphilis, an enlarged lymph node, usually in the groin area, is preceded by the appearance of an ulcer on the genitals, a hard chancre. Unlike other infectious diseases with syphilis, an enlarged lymph node can be painless. A long-term increase in several groups of lymph nodes may indicate diseases such as brucellosis, listeriosis, mononucleosis, and HIV infection.
Tumor lesion of the lymph nodes can be the result of both lymphoproliferative diseases, when the tumor initially comes from the lymph node, and the result of a metastatic lesion. Lymphogranulomatosis and lymphosarcoma primarily refers to lymphoproliferative diseases. Lymph nodes in these diseases increase to 3-4 cm, and sometimes more, while becoming dense. When feeling such lymph nodes are painless. With an initial increase in intrathoracic and intra-abdominal lymph nodes, lymphoproliferative diseases may not be recognized immediately.
Metastatic lymph node damage is observed in a number of diseases. In this case, the tumor cells enter the nodes through the lymphatic ducts. Multiplying, they lead to an increase in the lymph node. Most often metastasizes to lymphatic breast cancer, melanoma, thyroid cancer, laryngeal cancer, cancer of the tongue, rectal cancer, lung cancer. In metastatic lesions, the lymph node is thick and painless.
An increase in the inguinal lymph nodes happens when:
- melanoma of the skin and squamous cancer of the skin of the lower extremities, lumbar and gluteal region;
- Rectal cancer;
- Cancer of the vulva;