The Lymphatic System

Found Body-Wide, it Offers Protection from Infection and More

Aug 8, 2009 Linda Mundorff

The lymphatic system is primarily known for its ability to protect the body from infection. Nevertheless, it also functions to maintain fluid balance and to absorb fat.

The lymphatic system is composed of lymphatic vessels, lymph nodes, and lymph (fluid), a one-way system that ends at the capillary level of the circulatory system.

The tissues of this system are highly permeable and can absorb fluids and large molecules left behind by the circulatory system.

Function

The function of the lymphatic system is to provide:

• fluid and protein balance
• absorption of fat in the digestive system
• protection against microorganisms and other foreign substances

Lymphatic Vessels

Lymphatic vessels parallel the circulatory system, with one-way valves to prevent back flow. There are two sets of vessels, the superficial ones, which lie below the skin and the deep vessels, which can be found running alongside the deep veins.

The fluid (lymph) flowing through these vessels are filtered and drained via masses of lymphatic tissue called lymph nodes. The lymph leaves the nodes and eventually drains into one of two terminal vessels: the right lymphatic duct and the thoracic duct.

Lymph Nodes

Lymph nodes are composed of clusters of lymphatic tissue that have two purposes, to filter lymph and to house lymphocytes of the immune system. Lymphocytes function to destroy foreign microorganisms and other substances before they have an opportunity to travel to other parts of the body.

Often when a person gets sick the doctor will check the glands in the neck; these glands are actually lymphatic nodes and when overwhelmed with infection become swollen and painful.

Lymphatic Organs

Lymphatic tissue is distributed throughout the body and is a component of the following specialized organs:

• The tonsils
• The thymus
• The spleen

Tonsils

The tonsils are the body's first line of defense against airborne or swallowed microorganisms. The tonsils are located in three different areas of the oral-pharyngeal cavities: the palatine, adenoids, and the lingual tonsils.

Thymus

The thymus is located in the chest behind the sternum and is an important organ of the immune system. At birth, it is quite large and offers protection to the newborn. The gland is active during childhood and after puberty; it begins to shrink and is replaced with connective tissue and fat.

Specialized lymphocytes mature within the thymus. The immune system will trigger the release of these mature cells when needed.

Spleen

The spleen is known as the graveyard for Red Blood Cells (RBC). It filters and cleanses the blood and breaks down old or defective RBCs. The spleen is a vascular organ, which means it contains a lot of blood. The spleen acts as a reservoir for blood and releases it when needed.

Disorders

Many conditions plague this system; with lymphedema being one of the most common. Lymphedema is a disorder of the fluid balance component of the system and is characterized by copious amounts of fluid usually found in the legs and feet. Some suggest that lymph massage would help this condition, but check with your physician before starting this type of massage because in some cases it can worsen the condition.

Diseases and problems with the lymphatic system can impede the body's ability to protect against infection. Moreover, one of the worst prognoses to receive, is that cancer cells have migrated and spread into the lymphatic system.

There are a number of serious conditions associated with this system; ranging from worm infiltration as in Lymphatic Filariasis to a genetic condition found in Milroy Disease. Some other serious diseases are:

• Lymphoma
• Castleman Disease
• Non-Hodgkin's Lymphoma
• Splenomegaly
• Autoimmune diseases
• Hodgkin's Disease

In conclusion, the lymphatic system and its organs are widespread and scattered throughout the body. It functions to service almost every region of the body. Because the vessels of the lymphatic system span the entire body it becomes an easy portal for the spread of cancer and other diseases, which is why disorders and diseases of this system can be so devastating.

The copyright of the article The Lymphatic System in General Medicine is owned by Linda Mundorff. Permission to republish The Lymphatic System in print or online must be granted by the author in writing.

Lymphatic System

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