The Lymphatic System Was Once A Well Guarded Secret

I have written a number of columns about the ability of our bodies to perform without our interference.  Whether it be breathing, circulation, absorption, digestion, excretion, healing, infection control, or immunity, we are fortunate that each of these vital involuntary functions is not left for us to command.  As examples, imagine having to remember to breath every few seconds (normal respiration rates are 12 to 16 times a minute), or to make sure your heart beats 100,000 times a day,  or to recognize an invading foreign substance that attaches to our lungs.  We would certainly not survive. There was, however, one other system I had neglected.  I am referring to our lymphatic system and it is finally receiving growing acclaim and well deserved attention by the medical profession.  This system is often referred to as our built in self cleaning apparatus and this network of vessels, tissues, and organs helps the body rid itself of invading microbes, other foreign materials and remove waste. 

The lymphatic system is a part of the circulatory system composed of conduit networks. These networks are known as the lymphatic vessels. These are vessels that bring a clear liquid to the heart. Thomas Bartholin and Olaus Rudbeck first described this system during the 17th century. Unlike the cardiovascular system the lymphatic system is not closed.  Lymph flows in one direction toward the heart. The system  works with the blood vessels and the heart to help bring back a significant portion of the liquid lost during blood circulation. By doing so, your body can ensure balanced electrolytes through fluid homeostasis in your body.

The lymph is the watery fluid that flows through the vessels of the system. This may be considered as the closest counterpart of the blood from the circulatory system. This liquid is responsible for the transportation of white blood cells and other similar immune system components. Essentially, the lymph is also composed of a considerable amount of plasma and other liquid components of the blood.

Lymph nodes are organized collections of lymphoid tissues where the lymph passes through before they return to the main blood flow. These are found in intervals along the entire lymphatic system. The lymph node components are essentially similar to the components of the kidneys. A lymph node is typically composed of the following: (1) cortex; (2) medulla; and (3) hilum.  Numerous afferent (conducting inward) lymph vessels can bring in the lymph and makes their way through the inner parts of the lymph nodes. The liquid is then drained out using the efferent (conducting outward) lymph vessel.  White blood cells inside the nodes, called lymphocytes, attack and destroy disease causing microbes. This process causes the lymph nodes to become inflamed when an infection is present.

According to James Rosenthal in his book about the lymphatic system, its’ most important function is to transport and collect the transport tissue fluids. The transport tissue fluids typically come from the intracellular spaces. These intracellular spaces, in turn, are found in most of the tissues in your body. After bringing the fluids to these regions, this system then brings the fluids back to the circulatory system through the veins.  The lymphatic system also assumes an important role when it comes to the return of plasma proteins to the blood stream. This is important because the plasma proteins contain the blood components that significantly aid in wound healing and skin layer regeneration. This is because the plasma proteins contain the necessary substances that can help produce the reinforcing agents to help stop blood clotting. These substances can also help produce the temporary layer that can help prevent the entry of more foreign bodies into your system.

Unlike the cardiovascular system, which is powered by the heart, the lymph system lacks a pump.  Instead it relies on the body’s movements.  When muscles contract, they help push the fluid through the lymph vessels.

The lymphatic system is more than just a drainage system, it includes organs that product protective lymphocytes, such as bone marrow and the thymus gland (located between the lungs) as well as organs where the white blood cells do their job of destroying microbes. Tonsils (another part) trap germs that are inhaled or ingested, while tissues in the lining of the gastrointestinal tract destroy pathogens that attempt to escape the large intestine.

Final Thoughts

Here are a few hints from a recent Health magazine to support the lymphatic system: (1) exercise, muscle movement help pump lymph throughout the body, (2) practice deep diaphragmatic breathing, which stimulates the thoracic duct, the largest lymph vessel in the body, (3) drink enough water or fluids to be well hydrated, (4) get proper rest, (5) avoid exposure to cleaning products and pesticides, and (6) gently massage your skin using a brush with firm, natural bristles to encourage lymph flow.  Use long, circular motions starting at the ankles and moving toward the heart.

Max Sherman is a medical writer and pharmacist retired from the medical device industry.  His new book “Science Snippets” is available from Amazon and other book sellers. It contains a number of previously published columns.  He can be reached by email at  maxsherman339@gmail.com.