The lymphatic system is an vital part of the immune system . The central function of the lymphatic system is to filter out and remove waste from body tissue. These waste products may include dead cells, pathogens, and toxins. The lymphatic organs include the lymph nodes, spleen, and thymus. These organs are connected by a network of lymphatic vessels, which act like drainage vessels. These vessels run almost parallel to the blood vessels. The lymph vessels structures are porous and allow immune cells and fluids to move easily between the blood and lymphatic systems. Waste from the bloodstream is able to leak into the lymphatic vessels, like a drainage tube. The lymphatic vessels are filled with a clear fluid called lymph that flows around the body tissue. Lymph fluid bathes body tissue and carries in nutrients. This lymph "bath" as it is referred to, also serves to remove waste materiel and excess fluids from body tissues. The lymphatic system allows immune cells access to tissue throughout the body. The lymphatic system is lined with lymph nodes shaped like small beans. You can easily feel your lymph nodes under your arms, on the sides of your neck, and in the groin. The lymph fluid flows through the lymph nodes carrying the waste products collected from the body tissue and blood. These waste products are filtered out as they flow through the lymph nodes. In this way, the lymph nodes serve as a filter to remove pathogens such as viruses, bacteria, or other foreign matter.. Once caught in the lymph nodes, pathogens are destroyed by white blood cells. When the body is fighting an infection, a lymph node will swell because of the ongoing battle. In addition to being a filtration system, the lymph nodes produce and store white blood cells. Furthermore, when needed, immune cells are released into the lymphatic vessels where they are able to make their way into the blood stream. In this way, the lymphatic system offers the immune cells roadways to access to all body tissue, filters out pathogen waste products, and makes and stores white blood cells the kill trapped pathogens.
The organs of the lymphatic system play a central role in the development of the cascade of differentiated immune cells. The white blood cells, or lymphocytes, originate from stem cells located in the red bone marrow at the middle of our bones. However some immune cells travel to other organs to mature. One of these organs is the thymus, which is located just above the heart. The thymus gland is largest in the early teens and then slowly shrinks in old age to about the size of a grape. T-cells travel from the bone marrow to the thymus where they then develop fully. B-lymphocytes leave the bone marrow and travel to the spleen and lymph nodes, where they continue to produce.
Another organ of the lymphatic system is the spleen. The spleen serves to store and filter blood. This filtration removes and recycles abnormal and dead blood cells. When microbes and toxins are removed , they can activate a specific immune response.
To summarize, the lymphatic system plays a vital role in body's defense system, by using its body wide drainage vessels it is able to filter and destroy trapped pathogens and remove waste products. In addition, the lymphatic system is able to produce and deploying immune cells as needed.