“… the lymphatic system is no less essential than the blood circulatory system for human health and well-being.”

Lymphs are a part of blood circulation, the Lymphatic system is the sewer of our bodies. Its task is to return the interstitial fluid of blood plasma that isn’t absorbed back to the blood flow and has dripped between cells through capillary action. The lymphatic system also collects the metabolic waste developed in tissues, moving it first to the veins and then along to the liver where it is processed. Together with blood circulation the Lymphatic system is in charge of the immune system, protecting our bodies from viruses and bacteria. By moving the lymph through at least one lymph node at a time, the lymphatic system is taking care of the immune system by loosening lymphocytes and therefore removing microbes from the body. Lymphatic vessels also take care of the absorption of edible fats.

Lymphatic vessels start next to the capillaries as solid capillary branches, these then join together as bigger lymphs. They run next to blood vessels usually surrounding the veins with small lymph branches. Lymphs move the lymphatic fluid from the tissue in the lower limbs, pelvis and intestines through the cisterna chyli and along to the biggest collection of lymphatic vessels in the body, located in the thoracic duct (ductus thoracicus). The lymph of the intestines moving to the thoraric duct under the chest is coloured white by long-chain fats in the small intestine. Otherwise the lymph is usually clear, since it consists mostly water, proteins, fats, salts, white cells and micro organisms. The lymphs from the left side of the upper body go to the joint between the left jugular vein and subclavian vein, where the thoraric duct also releases the lymphs into circulation of the Lymphatic system. From the right side of the head, the right arm and a part of the chest the lymph returns to circulation via lymph duct through the right subclavian vein.

The Lymphatic system and blood circulation are in tight interaction with each other.

The blood circulation and lymphatic system are the two biggest fluid circulation systems in our bodies. Even though they share a lot of similarities and were documented by Hippocrates (circa 460-370 BC) they have been studied very differently by the medical and scientific communities. Blood circulation has been widely researched, but the lymphatic system has gotten a lot less attention from the medical community. Therefore its significance for our bodies has been largely overlooked.

The study of the lymphatic system has been inadequate, since imaging the lymphs is challenging. However, new techniques for imaging these small, clear lymphs have been developed, and thanks to the newer equipment, the significance of the lymphatic system is becoming clearer to us. This will also open up new opportunities for studying the brain and allow us to explore the role of a dysfunctional lymphatic system in several diseases.

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