By Riva Preil
Approximately 10% of water that exits the capillaries and enters the interstitial space at the arterial end of the capillary does NOT return at the venous end due to pressure related factors (refer to Starling’s Equation for more details). This “extra” water (referred to as the lymphatic load) enters the lymphatic system at lymphatic capillaries to the venous angles (the junction of the left subclavian vein and the internal jugular vein). The lymphatic system meets the circulatory system at the venous angles, and it is where the extra water is returned to the circulatory system.
Furthermore, certain molecules, including fats from the digestive system and certain large proteins, are TOO LARGE to travel through the narrow diameters of the circulatory vessels. Instead, they travel through the larger lymphatic vessels along with the water.
Now, moving on to the title of this blog…It would be impossible to explain the lymphatic system without mention of our ever so crucial LYMPH NODES. Lymph nodes are small oval shaped organs that contain white blood cells, T cells, and B cells which are responsible for fighting infection and are a component of the immune system). All lymph fluid travels through a series of lymph nodes, which are also responsible for filtering the lymphatic fluid. There are approximately 600 lymph nodes in the average adult human body.