At the center of the body’s immune system is a system called the lymphatic system. Like blood vessels, it is a network that travels throughout the body, transporting lymph fluid through lymph vessels from the ends of the body to a central outlet that connects to veins.
Blood oozes out of the capillaries and delivers oxygen and nutrients to the cells. Still, the water that does not make it back into the blood vessels again is called tissue fluid, and this tissue fluid taken up by the lymph vessels is called lymphatic fluid. The lymphatic vessels collect the tissue fluid and transport it to the veins as lymphatic fluid, which allows the blood to circulate in the body without significantly reducing its volume.
The main components of tissue fluid are plasma and lymphocytes from the blood, but bacteria, viruses, and cellular waste are also taken into the lymph vessels. Lymph nodes located in various lymph vessels act as a checking station, filtering the lymph fluid to prevent pathogens such as bacteria and viruses from entering the veins.
About 600 to 700 lymph nodes are distributed throughout the body, where various types of white blood cells, which are immune cells, gather to attack and dispose of bacteria and viruses that reach the nodes. For example, the tonsil, one of the lymph nodes, can swell up when you have a cold. It is a sign that the lymphocytes are fighting against pathogens.
The lymphatic system collects waste and excess water, so if the lymph’s flow is impaired, the body will also become swollen, and the immune system will weaken. If you feel cold and sluggish along with swelling, there is often a problem with lymph flow. Lymphatic massage and sauna are well–known ways to improve lymphatic flow, but only moving your legs can also be effective. Make sure to walk often in your daily life to promote the flow of lymph fluid.