The Lymphatic System
What is lymph anyway?
It is wise to get an understanding of the circulatory system if you want to understand the lymphatic system. As blood is pumped throughout the body by the heart, it brings oxygen and nutrients to all the cells as it passes out of the tiny arteries called capillaries. When the blood plasma passes out of the capillary walls and into the surrounding tissues, it is called interstitial fluid. At the cell walls, we see an exchange of nutrients, oxygen and metabolic waste products into and out of the cells. After this exchange, most of the plasma reenters the capillaries and begins it travel back to the heart through the veins. A very small percentage of this fluid returns via the lymphatic system.
This plasma (now called lymph) contains proteins that are too large to enter the capillary walls and therefore cannot return through the blood system. Removal of this protein is essential because proteins attract water to themselves; therefore excess protein in the interstitial spaces causes fluid swelling or edema. Lymph vessels collect this protein-rich fluid as well as waste products, bacteria, viruses, inorganic substances, water and fat.
Unlike the circulatory system, which depends on the heart to circulate blood, lymph vessels move the fluid using hundreds of tiny muscular units contracting throughout the lymph vessels as well as physical movement of the body to encourage fluid flow. This flow enables the lymph vessels to transport the numerous substances to lymph nodes which can then filter and process them. The action of these muscular units can be compromised or stopped due to surgery, radiation, trauma, burns, infections, substantial swelling, fatigue, stress, or age. When the lymph circulation stagnates, fluids, proteins and toxins accumulate, and cellular happiness is significantly compromised.
As the fluids accumulate under the skin, they can cause a swelling called lymphedema.