The lymphatic system is a major component in the body's immune system and its main function is to aid the body in fighting off disease.
The lymphatic system also absorbs fats or lipids from the intestine and helps transport them to the blood.
The lymphatic system works together with the cardiovascular system to help return fluids that may have escaped from the blood vessels back into the bloodstream, in this way it helps in maintaining the body's fluid balance.
In simpler terms, the lymphatic system is the body's drainage system.
The thymus, spleen, bone marrow and Mucosa-associated lymphoid tissue (MALT) all comprise the lymphatic system along with lymph nodes.
Lymphatic tissue such as MALT occurs throughout the body and is generally named according to location, for example lymphoid tissue in the gut is referred to as GALT (gut associated lymphoid tissue) and bronchial lymphoid tissue is known as BALT or bronchial/tracheal associated lymphoid tissue and so on.
The purpose of lymphoid tissue is to protect the body from antigens and to fight off disease.
Lymph nodes are the most visible part of the lymphatic system and their main role is to produce lymphocytes for fighting off disease.
Lymphocytes are a type of white blood cell.
The lymphatic system resembles the circulatory system of the body in the way it is intricately made up of numerous channels and ducts that run parallel to blood vessels.
Lymphatic vessels merge into a main channel at the end of their journey and this is known as the thoracic duct.
Lymph makes its final journey into the heart and is then pumped to the lymph nodes.
The largest organ in the lymphatic system is the spleen.
Its function is to store and collect red blood cells and proteins as well as white blood cells or lymphocytes.
The spleen also filters undesirables from the blood.
Bone marrow is another vital component in the lymphatic system; its primary job is to produce red and white blood cells.
Bone marrow is found in the central shaft of bones and consists of connective tissue and cells.
The thymus is an organ that produces the body's first immune cells.
It begins to shrink in size as the body matures into adulthood.
Disorders of the Lymphatic System in Dogs: Lymphoma: Also known as lymphosarcoma, is a cancer of the white blood cells.
It is one of the most common cancers that affect dogs and can affect one or more parts of the lymphatic system.
Chemotherapy is the most commonly prescribed form of treatment.
Lymphadenopathy: Lymphadenopathy results in the swelling of the lymph nodes; it can be representative of lymphosarcoma but can also be caused by other factors.
Reactions to vaccinations or chronic inflammation can result in enlarged lymph nodes.
Lymphadentitis: This condition occurs when the lymph nodes are inflamed.
It can affect one or several lymph nodes depending on cause.
Wounds, infections and tumors can cause lymhpadentitis.
Lymphangitis: Is an inflammation of the lymph vessels.
Foreign bodies, trauma and infections can cause this condition and it can occur concurrently with lymphadentitis.
Lymphedema: This disease is caused by the accumulation of lymph in the soft tissues.
It affects the limbs and can be extremely painful and debilitating.
Certain breeds such as Labrador retrievers, poodles and Great Danes are susceptible to a congenital form of the disease.