The lymphatic system is a network of vessels found throughout the body. A system that works to drain excess and unnecessary fluid from tissues, the Lymphatic system is an essential function for human life. The system works to provide a balance of fluids and helps the body defend itself against microbial organisms including, viruses, diseases, and fungi. Lymphatic can be found throughout the human body except for the nervous system. Consequently, the lymphatic system works together with the circulatory system; wherever there are lymph vessels, blood vessels can also be found. Lymph vessels carry a substance called lymph. Lymph is described as a fluid that is typically clear. The fluid is made up of water, protein, molecules, salts, glucose, urea, lymphocytes, and other substances, which is resembled to blood plasma. Parts associated with the lymphatic system can be found close to gastrointestinal tracts, including bone marrow, spleen, thymus gland, lymph nodes, lymphatic tissue, and tonsils. Most of the body’s important organs have lymphatic tissue like the heart, liver, skin, lungs, and intestines.
The lymphatic system has three major functions:
- To fight immunity and filtering the body of waste
- Return or circulate materials from the lymphatic system and into the blood stream
- Process the movement of hormones, nutrients, and oxygen
Movement of Fluid
The essential task of the lymphatic system is the movement of fluids. Lymph moves slowly throughout the body, slower than blood flow. This is because lymph does not have a pump to help fluid move and circulate throughout the body. Instead, lymph is pushed along by skeletal contractions and respiration. The lymph is drained into lymph capillaries. Lymph capillaries flow in one direction and is open ended. From the capillaries the lymph passes to the lymphatic vessels and through the lymph nodes.
The thoracic duct is a major lymphatic vessel. It goes through the chest and empties through a large vein on the left side of the neck. The vessel starts at the lower spine, collecting lymph from various parts of the body, including the left side of the body and the rest of the extremities. The extremities include the limbs, lower chest, pelvis, and abdomen. The right lymphatic duct empties through a large vein on the ride side of the neck. It gathers lymph from the neck, chest, and arm.
Filtration of the Lymphatic System
Without the lymphatic system, the body’s tissues and organs would swell from excess fluid, allowing harmful organisms to attack the body. As a result, it is important for the system to filter out harmful bacteria and waste, keeping the body free from pathogens. Lymph nodes provide the important function of filter. Lymph nodes are made up of tissues, networked together to form a mesh. Afferent lymphatic allows lymph to enter the node and work its way into an entry called sinuses; flowing into the cortical sinuses and into the medullary sinuses. Macrophages, phagocytic cells which lines the sinuses, attack and kill things like bacteria, damaged cells, dead tissue, foreign matter, and unwanted protein. Macrophages destroy these things by taking in lymphocytes that produces an immune response and creating antibodies.
Circulation and Return of Fluids
Filtered lymph is always returned and recirculates back in to the blood stream and circulatory system. Cleaned and reusable lymph is able to leave the node through the efferent lymphatic. The efferent lymphatic allows the lymph to return to the vein through the lymph trucks. It is the lymph trunks that enable the fluid to enter the thoracic duct and the right lymph duct, two primary ducts of the system. The lymph is divided among the two ducts according to the areas in which they originated. Consequently, all lymph that came from the left side is released into the thoracic duct while the right lymph duct receives lymph from the right side. From the subclavian vein, the lymph is able to reenter the blood stream.
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