That's why doctors check for swollen lymph nodes sometimes called swollen "glands" in the neck when someone has a sore throat.
This is called lymphadenopathy. Reviewed by: Larissa Hirsch, MD. Larger text size Large text size Regular text size. What Are the Spleen and Lymphatic System? What Does the Spleen Do? The body also uses the spleen as a place to store blood and iron for future use. What Does the Lymphatic System Do? Antigens and Antibodies Antibodies also known as an immunoglobulins are Y-shaped proteins produced by B-cells,that bind to specific antigens on the surface of foreign objects such as bacteria and viruses.
This identifies and 'tags' the foreign object as 'non-self', signalling other immune cells to attack them. Hormones and the Immune System There are several hormones generated by the immune system. These hormones are generally known as lymphokines. Steroids and corticosteroids components of adrenaline suppress the immune system. Cancer Focus Metastatic spread of cancer via the lymph nodes Lymph nodes close to the primary tumor are often the first site of metastases spread of cancer.
Lymph node metastases are rarely life threatening, but their detection is a prognostic factor for many types of cancer as it shows the tumor has developed the ability to spread. Tumor cells may travel via the lymphatic system and spread to to lymph nodes and distant organs. Sentinel Lymph Node Biopsy A dye is injected near the primary tumor to identify the position of the sentinel lymph node the first lymph node to which cancer cells are most likely to spread as the lympatic system drains fluid away from the tumor.
The sentinel node is surgically removed and a pathologist checks for the presence of cancer cells. SLNB is most frequently used to help stage breast cancer and melanoma. It is a less extensive operation compared to standard lymph node surgery.
Immunosuppression This is reduced activity or efficiency of the immune system and its ability to fight infections and other diseases. Certain diseases such as AIDS or lymphoma can cause immunosuppression. It is also a common side-effect of anticancer chemotherapy, leading to cancer patients having an increased risk of infections during treatment. Lymphoma A general term form for malignant disease of the lymphatic tissue characterized by abnormal, uncontrolled cell growth.
There are a number of types of lymphoma, including Hodgkin Lymphoma, with most other types classed together as Non-Hodgkin Lymphoma. Hodgkin Lymphoma A malignancy of the lymphatic tissue that occurs most often in males, and the peak incidence is between ages 15 and It is characterised by progressive, painless enlargement of the lymph nodes, spleen, and general lymph tissue. In Hodgkin Lymphoma Reed-Sternberg cells a specific type of lymphocyte become abnormal and grow in an uncontrolled way.
There are many different types of NHL. Some grow very slowly, whilst others grow quickly and need aggressive treatment. These can rapidly multiply and release antibodies in response to bacteria, viruses, and a range of other stimuli from dead or dying cells and abnormally behaving cells such as cancer cells.
The blood in our blood vessels is under constant pressure. All of the fluids and its contents that leak out into the tissues as well as waste products formed in the tissues, and bacteria that enter them through our skin are removed from them by the lymphatic system.
When the lymphatic system does not drain fluids from the tissues properly, the tissues swell, appearing puffy and uncomfortable. If the swelling only lasts for a short period it is called oedema. If it lasts longer more than about three months it is called lymphoedema. The lymphatic vessels are found everywhere in our body.
Generally, more active areas have more of them. The smaller lymphatic vessels, which take up the fluids, are called lymph capillaries. The larger lymphatic vessels have muscles in their walls which helps them gently and slowly pulsate. These larger lymphatic vessels also have valves that stop the lymph flowing back the wrong way.
Lymph vessels take the lymph back to the lymph nodes there are about of these in total , which are found in our arm pit and groin as well as many other areas of the body such as the mouth, throat and intestines. The fluid that arrives in the lymph nodes is checked and filtered. Most of it continues on to where the lymphatic system from most of our body the left arm, tummy, chest, and legs empties out at the left shoulder area.
Lymph from the right arm and face and part of the right chest empties into the blood at the right shoulder area. The spleen is located in the abdominal tummy area on the left side, just under the diaphragm.
It is the largest of our lymphatic organs. The spleen does many things as it filters and monitors our blood. As well as removing microbes, the spleen also destroys old or damaged red blood cells. They have many functional roles in the body, most notably:. The red bone marrow and thymus are considered to be primary lymphoid organs, because the majority of immune cells originate in them. Bone marrow is a soft, gelatinous tissue present in the central cavity of long bones such as the femur and humerus.
Blood cells and immune cells arise from the bone marrow; they develop from immature stem cells haemocytoblasts , which follow distinct developmental pathways to become either erythrocytes, leucocytes or platelets. Stem cells rapidly multiply to make billions of blood cells each day; this process is known as haematopoiesis and is outlined in Fig 2. To ensure there is a continuous production and differentiation of blood cells to replace those lost to function or age, haematopoietic stem cells are present through adulthood.
In the embryo, blood cells are initially made in the yolk sac but, as development of the embryo proceeds, this function is taken over by the spleen, lymph nodes and liver.
Later in gestation, the bone marrow takes over most haematopoietic functions so that, at birth, the whole skeleton is filled with red bone marrow. Red bone marrow produces all erythrocytes, leucocytes and platelets.
Haematopoietic stem cells in the bone marrow follow either the myeloid or lymphoid lineages to create distinct blood cells Fig 2 ; these include myeloid progenitor cells monocytes, macrophages, neutrophils, basophils, eosinophils, erythrocytes, dendritic cells and platelets , and lymphoid progenitor cells T-lymphocytes, B-lymphocytes and natural killer cells. Some lymphoid cells lymphocytes begin life in the red bone marrow and become fully formed in the lymphatic organs, including the thymus, spleen and lymph nodes.
As puberty is reached and growth slows down, physiological conversion occurs, changing red bone marrow to yellow bone marrow. This entire process is completed by the age of 25 years, when red bone marrow distribution shows its adult pattern in the bones. However, under particular conditions, such as severe blood loss or fever, the yellow marrow may revert back to red marrow Malkiewicz and Dziedzic Any disease or disorder that poses a threat to the bone marrow can affect many body systems, especially if it prevents stem cells from turning into essential cells.
A growing number of diseases can be treated with a bone marrow transplant or haematopoietic stem cell transfer; this is often achieved by harvesting suitable donor stem cells from the posterior iliac crests of the hip bone, where the concentration of red bone marrow is highest. The thymus gland is a bi-lobed, pinkish-grey organ located just above the heart in the mediastinum, where it rests below the sternum breastbone. Structurally, the thymus resembles a small bow tie, which gradually atrophies shrinks with age.
In pre-pubescents, the thymus is a relatively large and very active organ that, typically, weighs around 40g, but in a middle-aged adult it may have shrunk sufficiently to be difficult to locate. Each of the two lobes of the thymus is surrounded by a capsule, within which are numerous small lobules — typically measuring mm in width — which are held together by loose connective tissue.
Lobules have two distinct areas:. In addition to being a major lymphoid organ, the thymus is also recognised as part of the endocrine system because it secretes a family of hormones collectively referred to as thymosin; this is a group of several structurally related hormones secreted by the thymic epithelial cells. These hormones are essential for normal immune function and many members of the thymosin family are used therapeutically to treat cancers, infections and diseases such as multiple sclerosis Severa et al, T-cells originate as haematopoietic stem cells from the red bone marrow Fig 2.
A population of these haematopoietic stem cells infiltrate the thymus, dividing further within the cortical regions of the lobules then migrating into the medullary regions to mature into active T-cells; this process of T-cell maturation is controlled by the hormone thymosin.
The importance of these cells is apparent in patients who have depleted T-cell populations, such as those infected with HIV. This process allows mature T-cells to distinguish foreign, and therefore potentially pathogenic, material from antigens that belong to the body.
It has been demonstrated that removal of the thymus may lead to an increase in autoimmune diseases, as this ability to recognise self is diminished Sherer et al, Diseases of the thymus include thymic cancer and myasthenia gravis MG.
MG occurs when the thymus produces antibodies that block or destroy the muscle-receptor sites, causing the muscles to become weak and easily tired. It most commonly affects muscles that control the eyes and eyelids, resulting in droopy eyelids and difficulty making facial expressions; chewing, swallowing and speaking also become difficult. In most cases of either MG or thymic cancer, thymectomy is recommended.
Patients who have had a thymectomy may develop an immunodeficiency known as Good syndrome, which increases their susceptibility to bacterial, fungal and viral opportunistic pathogens; this condition is, however, relatively rare.
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