According to Springfield Technical Community College, lymph capillaries collect the fluid that collects in between the body’s cells. This extracellular fluid is created when fluid is forced through the walls of the capillaries because of the high amount of pressure in the system. This fluid makes its way to the lymph capillaries, which transport the fluid to the lymph vessels, where it is reintroduced to the bloodstream.
Lymph is primarily composed of plasma proteins, macrophages, wastes and white blood cells. Unlike the circulatory system, the lymphatic system is open-ended. As explained by the Springfield Technical Community College, lymph enters the lymphatic system at the lymph capillaries and only flows in one direction. Unlike the circulatory system, the lymphatic system operates under extremely low pressure. Valves occur along the length of the lymph vessels, which prevent the liquid from flowing backwards.
Lymph circulation is greatest during periods of exercise, as the movements of the skeletal muscles help propel it along, according to Springfield Technical Community College. This is part of the reason that patients develop edema, or fluid-caused swelling, when bedridden for extended periods of time. If a blockage or break occurs in the lymph vessels, the fluid inside can spill into the surrounding tissues.