In general, people understand the three main highway systems in the human body, the arteries, the veins and the nerve cell pathways carrying sensory messages to the brain and motor command back out; however, there is a fourth you don’t often hear described. Your LYMPHATIC SYSTEM works silently and continuously in your best interest. The major components of this system are the lymph fluid, lymph vessels, lymph nodes (including tonsils) ,thymus gland, spleen and bone marrow. Lymph fluid is derived from the liquid portion of the blood, the plasma consisting of water, proteins, salts, lipids (fats) and white blood cells (WBC). This liquid continuously bathes every cell; serving the dual purpose of maintaining fluid balance within the tissues and providing a delivery system for immune cells to combat recognized invaders such as bacteria and viruses, even other types of pathogens. This fluid then returns to the blood steam through a series of minuscule channels terminating in the chest near the heart. Components of this irrigation system include lymph nodes acting as filters of cellular debris from damaged or aging cells, collectors for tiny fat particles from the digestive system, even screens to trap migrating cancer cells before they can initiate a generalized spread. Lymph nodes are “home” for the lymphocytes generated from the bone marrow. They patiently bide their time like pac man in ambush waiting for any intruder.
Tonsils(adenoids) are the most obvious of this node system. Located at the back of the throat and behind the palate, their lymphocytes and macrophages are the guardians, the Horatio at the bridge, at the entrance to both the lungs and the digestive system. Unfortunately they are prone to becoming overwhelmed by whatever pathogen they meet, becoming so grossly enlarged they obstruct the airway requiring removal, a common malady mostly in preadolescent children.
Other components are the Thymus gland in the upper chest promoting the development of T-lymphocytes which in turn stimulate the main body of immune cell formation, the Spleen, the largest member of this system serving the dual purpose of blood cell reservoir and expunging old red blood cells, and the bone marrow itself site of stem cells from which immature lymphocytes spring. These migrate to the lymph node system where they mature and become your faithful guardians. Lymphocytes can be divided in to two broad groupings…B cells that form antibodies and T cells that wake up the entire immune system on demand.
The system works quietly and flawlessly to a great extent but it does have its own diseases. Lymphocytes can become cancerous themselves, fortunately rarely, as Hodgkin’s and non-
Hodgkins lymphoma. Oncology medicine advances have made this a largely controlled malady with substantial life expectancy prognosis.
As well, there is a complication of leg and arm surgery where multiple lymph nodes have been removed or damaged impairing lymph flow causing painful and disfiguring swelling of the limb beyond the surgical scar. The condition is titled LYMPHEDEMA and unfortunately represents an unavoidable complication in about 25% of women requiring more radical mastectomy for breast cancer. It is estimated there are upwards of 100,000 women with this post surgical complication and another 100,000 Canadian men and women with lymphedema from other types of procedures. There is no cure for this condition but a stocking sleeve can significantly reduce the swelling and discomfort. There is a rather expensive pneumatic pump system which has proven effective but is not generally available outside of hospitals in Canada. Newer surgical techniques wherein “sentinel” nodes are selectively biopsied at time of breast surgery is reducing the incidence of this affliction for many women.
Lymphedema in the lower limb constitutes a different challenge. It is sometimes seen after extensive vein surgery and with the combination of an already compromised vein drainage in lower limbs where gravity driven tissue pressures are already a factor especially in the elderly, and the diabetic, tissue breakdown and ulceration are often experienced. At present, the most effective management is a properly fitted orthotic stocking and diligence regarding early reporting and intervention where skin surface breakdown is observed
In perspective though, for the substantial majority, our lymphatics will remain a reliable silent life partner never reminding us of their vigilant attendance to our safety and protection. Now that is truly the best of friends.
Written by: Dr. David Carll