Did you know that your breathing habits may positively affect your lymphatic system?
Let’s begin with a review of the anatomy and functioning of the lymphatic system. Closely related to the cardiovascular system both anatomically and functionally, the lymphatic system is composed of capillaries; larger lymphatic vessels, called collecting vessels; the lymph fluid itself; lymph nodes; and numerous lymphatic ducts.
The journey of the lymphatic fluid looks like this: lymph fluid is picked up from the cells, where it travels via the lymphatic capillaries to the collecting vessels, then up to the lymphatic ducts, where it is filtered and returned to the bloodstream.
What is this lymph fluid? It is a fluid that is the byproduct of cellular function and respiration. It is extra, or interstitial, fluid containing bacteria, fat and proteins, fluid that remains between the cells which was not picked up by the bloodstream. It is a waste by-product discharged from the cells. This clear and colorless fluid is then transported to the lymph nodes, where it is filtered and cleaned of foreign substances, bacteria, proteins and other large particles. From the nodes, the lymph travels to the ducts, formed by the convergence of lymph vessels. They include the lumbar duct, the common duct that empties into the cisterna chyli, the cisterna chyli, the thoracic duct, the left jugular and subclavian ducts and the right lymphatic duct.*
Lymph, then, travels from the cells to the capillaries, to the nodes, through the ducts, to empty in the large blood vessels located at the base of the neck, where it is emptied back into the bloodstream. However, unlike blood, lymph moves in only one direction through a variety of parallel mechanisms:
- hydrostatic pressure;
- valves to prevent back flow;
- voluntary muscle contractions throughout the body;
- respiratory movements that create alternating pressures within the chest cavity (pressures created by the contraction and relaxation of the diaphragm and respiratory muscles);
- contractions of the abdominal wall upon forceful exhalation — vigorous exercise, coughing, sneezing — creating a positive pressure in the cisterna chyli that pushes the lymph up towards the large veins in the neck;
- pulsations of adjacent blood vessels throughout the circulatory system.*
Three liters of lymph enter the bloodstream every 24 hours. Since muscle contractions aid lymph flow, you can see how important general exercise is to aid turnover in your lymphatic system. Furthermore, the thoracic duct, cysterna chili, the lumbar duct and the common duct are all very near the diaphragm, our primary breathing muscle. The thoracic duct passes through an opening in the diaphragm.
On an anatomical level at the very least, you can see how deep breathing exercises may have a direct and positive impact on lymphatic flow. Deep breathing exercises create greater pressures within the chest and abdominal cavities. Additionally, through the contractions of the diaphragm and abdominal muscles, a positive pressure is created in the trunk to further push the lymph upwards towards their emptying ports in the neck.
Another reason to get moving and to do pranayama — powerful breathing exercises!
*Information taken from Anatomy by Ernerst W. April and Grant’s Atlas of Anatomy. Please note also that the above information is not comprehensive of the entire lymphatic system, which also includes the spleen and lymphocytes.