A lymph node is a small ball-shaped organ of the immune system. They can be distributed widely throughout the body including the armpit, stomach/gut and lower limbs and they are all linked by lymphatic vessels. Lymph nodes are garrisons of B, T, and other immune cells. Lymph nodes are found all throughout the body, and act as filters or traps for foreign particles. They are important in the proper functioning of the immune system.
Lymph nodes also have clinical significance. They become inflamed or enlarged in various conditions, which may range from trivial and common, such as a throat infection, to life-threatening such as cancers. In the latter, the condition of lymph nodes is so significant that it is used for cancer staging, which decides the treatment to be employed, and for determining the prognosis.
Lymph nodes can also be diagnosed by a biopsy whenever they are inflamed. Certain diseases affect lymph nodes with characteristic consistency and location.
Pathogens, or germs, can set up infections anywhere in the body. However, lymphocytes, a type of white blood cell, will meet the antigens, or proteins, in the peripheral lymphoid organs, which includes lymph nodes. The antigens are displayed by specialized cells in the lymph nodes. Naive lymphocytes meaning the cells have not encountered an antigen before enter the node from the bloodstream, through specialized capillary venules, known as high endothelial venules. After the lymphocytes specialize, they will exit the lymph node through the efferent lymphatic vessel with the rest of the lymph. The lymphocytes continuously re-circulate the peripheral lymphoid organs and the state of the lymph nodes depends on the type of infection. During an infection, the lymph nodes may expand due to intense B-cell proliferation in the germinal centers, a condition commonly referred to as "swollen glands". The lymph nodes function to filter and monitor the lymph for foreign particles.
Human lymph nodes are bean-shaped and range in size from a few millimeters to about 1-2 cm in their normal state. They may become enlarged due to a tumor or infection, or inflamed due to leukaemia. Lymphocytes, also known as white blood cells, are located within honeycomb structures of the lymph nodes. Lymph nodes are enlarged when the body is infected, primarily because there is an elevated rate of trafficking of lymphocytes into the node from the blood that exceeds the rate of outflow from the node. Secondarily it can be as a result of the activation and proliferation of antigen-specific T and B cell clonel expansion. In some cases, they may feel enlarged because of a previous infection; although you may be healthy you may still be able to feel them enlarged.
Lymph nodes also have clinical significance. They become inflamed or enlarged in various conditions, which may range from trivial and common, such as a throat infection, to life-threatening such as cancers. In the latter, the condition of lymph nodes is so significant that it is used for cancer staging, which decides the treatment to be employed, and for determining the prognosis.
Lymph nodes can also be diagnosed by a biopsy whenever they are inflamed. Certain diseases affect lymph nodes with characteristic consistency and location.
Pathogens, or germs, can set up infections anywhere in the body. However, lymphocytes, a type of white blood cell, will meet the antigens, or proteins, in the peripheral lymphoid organs, which includes lymph nodes. The antigens are displayed by specialized cells in the lymph nodes. Naive lymphocytes meaning the cells have not encountered an antigen before enter the node from the bloodstream, through specialized capillary venules, known as high endothelial venules. After the lymphocytes specialize, they will exit the lymph node through the efferent lymphatic vessel with the rest of the lymph. The lymphocytes continuously re-circulate the peripheral lymphoid organs and the state of the lymph nodes depends on the type of infection. During an infection, the lymph nodes may expand due to intense B-cell proliferation in the germinal centers, a condition commonly referred to as "swollen glands". The lymph nodes function to filter and monitor the lymph for foreign particles.
Human lymph nodes are bean-shaped and range in size from a few millimeters to about 1-2 cm in their normal state. They may become enlarged due to a tumor or infection, or inflamed due to leukaemia. Lymphocytes, also known as white blood cells, are located within honeycomb structures of the lymph nodes. Lymph nodes are enlarged when the body is infected, primarily because there is an elevated rate of trafficking of lymphocytes into the node from the blood that exceeds the rate of outflow from the node. Secondarily it can be as a result of the activation and proliferation of antigen-specific T and B cell clonel expansion. In some cases, they may feel enlarged because of a previous infection; although you may be healthy you may still be able to feel them enlarged.
