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LYMPHATIC SYSTEM
Secondly the lymphatic organs play an important part in the immune system, having a considerable overlap with the lymphoid system. Lymphoid tissue is found in many organs, particularly the lymph nodes, and in the lymphoid follicles associated with the digestive system such as the tonsils. The system also includes all the structures dedicated to the circulation and production of lymphocytes, which includes the spleen, thymus, bone marrow and the lymphoid tissue associated with the digestive system.
The blood does not directly come in contact with the parenchymal cells and tissues in the body, but constituents of the blood first exit
the microvascular exchange blood vessels to become interstitial
fluid, which comes into
contact with the parenchymal cells of the body. Lymph is the fluid that is
formed when interstitial fluid enters the initial lymphatic vessels of the
lymphatic system. The lymph is then moved along the lymphatic vessel network by
either intrinsic contractions of the lymphatic passages or by extrinsic
compression of the lymphatic vessels via external tissue forces (e.g. the
contractions of skeletal
muscles). Eventually, the
lymph vessels empty into the lymphatic ducts, which drain into one of the two subclavian veins (near the junctions of the subclavian veins with the
internal jugular veins).
LYMPHATIC SYSTEM DISORDERS
The lymphatic system is a network of tissues and
organs. It is made up mainly of lymph
The
lymphatic system clears away infection and keeps your body fluids in balance.
If it's not working properly, fluid builds in your tissues and causes swelling,
called lymphedema. Other lymphatic system problems can include
infections, blockage, and cancer.
LYMPH NODES AND CANCER METASTASIS
Metastatic lymph node cancer, cancer cells from a malignant
tumor of a distant organ
travel to the lymph nodes via the lymphatic or blood vessels and lodge within
the lymph nodes, where they continue to proliferate. These cells, when examined
under a microscope, are seen to resemble the cancer cells of the organ from
where they originated.
LYMPHOMAS
Lymphoma is a cancer of the lymphocytes, a type of cell that forms part of the immune system. Typically, lymphoma is present as a solid tumor of lymphoid cells. Treatment might involve chemotherapy and in some cases radiotherapy and/or bone marrow transplantation, and can be curable depending on the histology, type, and stage of the
disease. These malignant cells often originate in lymph nodes, presenting as an enlargement of the node (a tumor).
It can also affect other organs in which case it is referred to as extranodal
lymphoma. Extranodal sites include the skin, brain, bowels and bone. Lymphomas
are closely related to lymphoid leukemias, which also originate in lymphocytes but typically
involve only circulating blood and the bone marrow (where blood cells are generated in a process termed haematopoesis) and do not usually form static tumors. There are
many types of lymphomas, and in turn, lymphomas are a part of the broad group
of diseases called hematological neoplasms.
Thomas Hodgkin published the first description of lymphoma in 1832,
specifically of the form named after him, Hodgkin's
lymphoma. Since then, many
other forms of lymphoma have been described, grouped under several proposed
classifications. The 1982 Working formulation
classification became very popular. It introduced the category non-Hodgkin lymphoma
(NHL), divided into 16 different diseases. However, because these different
lymphomas have little in common with each other, the NHL label is of limited
usefulness for doctors or patients and is slowly being abandoned. The latest
classification by the WHO (2008) lists 70
different forms of lymphoma divided in four broad groups.
Although older classifications referred to histiocytic
lymphomas, these are recognized in newer classifications as of B, T or NK cell lineage. True histiocytic malignancies are rare and are classified as sarcomas.
LYMPHADENITIS
Lymphadenitis is an inflammation of the lymph nodes.
The lymph nodes, also called lymph glands, are part of the lymphatic system.
The lymphatic system is part of the immune system, and the lymph nodes produce
cells that help the body fight infections.
Blood/Lymph Disorder Spotlight
Inflammation
of the lymph nodes can arise due to infections or to non-infectious causes.
Infectious causes of lymphadenitis include both viral infections, such as HIV or upper
In
lymphadenitis, the nodes will swell near the site of an underlying infection,
inflammation or tumor. Symptoms of lymphadenitis include hard, swollen or
tender lymph nodes. In general, if the nodes are hard and immovable, cancer may
be a possible cause, but most cases of enlarged lymph nodes do not represent
cancer. Nodes that are softer and more pliable most likely result from an
infectious or benign process.
Tonsillitis
Tonsillitis is inflammation of the tonsils most commonly caused by a viral or bacterial
infection. Symptoms of tonsillitis include sore throat and fever. While no treatment has been found to shorten the
duration of viral tonsillitis, bacterial causes such as streptococcal pharyngitis are treatable with antibiotics. It usually takes one to three weeks to
recover.
MONONUCLEOSIS
Mononucleosis ("Mono", glandular fever, and, colloquially, the "kissing disease") is a disease most commonly caused by Epstein-Barr virus (EBV). EBV affects lymphocytes are white blood cells involved in the adaptive immune system. mononucleosis can also be caused by cytomegalovirus (CMV), a herpes virus most commonly found in body fluids. While CMV can cause mononucleosis, 85% of the cases are Associated with EBV. The disease can be found in Anyone But Is Most Commonly Contracted by adolescents and young adults ages 15-35. While CMV can cause mononucleosis, 85% of cases are associated with this virus. The disease can be found in anyone, but is most commonly contracted by teenagers and young adults ages 15-35.
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