Lymphatic System

The lymphatic system is a part of the circulatory system, comprising a network of conduits called lymphatic vessels that carry a clear fluid called lymph (from Latin lympha "water goddess") unidirectionally towards the heart. The lymphatic system was first described independently by Olaus Rudbeck and Thomas Bartholin. The lymph system is not a closed system. The circulatory system processes an average of 20 liters of blood per day through capillary filtration which removes plasma while leaving the blood cells. Roughly 17 liters of the filtered plasma actually get reabsorbed directly into the blood vessels, while the remaining 3 liters are left behind in the interstitial fluid. The primary function of the lymph system is to provide an accessory route for these excess 3 liters per day to get returned to the blood. Lymph is essentially recycled blood plasma.

Lymphatic organs play an important part in the immune system, having a considerable overlap with the lymphoid system. Lymphoid tissue is found in many organs, particularly the lymph nodes, and in the lymphoid follicles associated with the digestive system such as the tonsils. The system also includes all the structures dedicated to the circulation and production of lymphocytes, which includes the spleen, thymus, bone marrow and the lymphoid tissue associated with the digestive system.

The blood does not directly come in contact with the parenchymal cells and tissues in the body, but constituents of the blood first exit the microvascular exchange blood vessels to become interstitial fluid, which comes into contact with the parenchymal cells of the body. Lymph is the fluid that is formed when interstitial fluid enters the initial lymphatic vessels of the lymphatic system. The lymph is then moved along the lymphatic vessel network by either intrinsic contractions of the lymphatic passages or by extrinsic compression of the lymphatic vessels via external tissue forces (e.g. the contractions of skeletal muscles). The organization of lymph nodes and drainage follows the organization of the body into external and internal regions; therefore, the lymphatic drainage of the head, limbs, and body cavity walls follows an external route, and the lymphatic drainage of the thorax, abdomen, and pelvic cavities follows an internal route. Eventually, the lymph vessels empty into the lymphatic ducts, which drain into one of the two subclavian veins (near the junctions of the subclavian veins with the internal jugular veins).

Read more about Lymphatic System:  Terminology, Functions, Clinical Significance, Organization, Lymphoid Tissue, Function of The Fatty Acid Transport System, Diseases of The Lymphatic System, Development of Lymphatic Tissue, Lymphatico-venous Communications, History

Other articles related to "lymphatic system, lymphatic, lymphatics":

Nuchal Scan - Development of Nuchal Translucency
11 and 14 weeks of gestation, when the fetal lymphatic system is developing and the peripheral resistance of the placenta is high ... After 14 weeks the lymphatic system is likely to have developed sufficiently to drain away any excess fluid, and changes to the placental circulation will result in a drop in peripheral ... is due to a blockage of fluid in the developing fetal lymphatic system ...
Head And Neck Anatomy - Lymphatic System
... The lymphatic system drains the head and neck of excess interstitial fluid via lymph vessels or capillaries, equally into the right lymphatic duct and the thoracic duct ... The tonsils also are lymphatic tissue and help mediate the ingestion of pathogens ... Together this set of lymphatic tissue is called the tonsillar ring or Waldeyer's ring ...
Lymphatic System - History
... Hippocrates was one of the first people to mention the lymphatic system in 5th century BC ... The first mention of lymphatic vessels was in 3rd century BC by Herophilos, a Greek anatomist living in Alexandria, who incorrectly concluded that the "absorptive veins of the lymphatics," by which he ... breakthrough came when in 1622 a physician, Gaspare Aselli, identified lymphatic vessels of the intestines in dogs and termed them venae alba et lacteae, which is now known as simply the lacteals ...
Lymphology - Diseases of The Lymphatic System
... caused by the accumulation of lymph fluid, which may occur if the lymphatic system is damaged or has malformations ... and metastasis of cancerous cells via the lymphatic system ... Lymphangiomatosis is a disease involving multiple cysts or lesions formed from lymphatic vessels ...
Florence R. Sabin - Biography
... While at Hopkins, Sabin’s observational skills and perseverance in the laboratory captured the attention of anatomist Franklin P ... Mall ...

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