The lymphatic system is composed of lymph organs, lymph nodes, lymph ducts, and lymph vessels. Lymph organs include the bone marrow, spleen and thymus.
The lymphatic system transports a watery clear fluid called lymph. At the same time, it works in close cooperation with immune system and circulatory system to perform its important functions.
The lymphatic system works with immune system to fight off diseases. Lymphocytes, produced in the bone marrow, circulate throughout the lymphatic system and destroy pathogens that invade our body.
Secondly, the lymphatic system works with the circulatory system to deliver nutrients, oxygen, and hormones. Lymph fluid also removes excess fluid, waste, cancer cells and toxins, and collects or returns interstitial fluid, which thus helps maintain body fluid balance.
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If to explain only mechanically---system is instrumental in drawing off of superfluous liquid from tissue . There are little lymphatic capillaries in all tissues, intercellular solution penetrates and concentrated in them, forming a lymph. Lymphatic capillaries meet in lymphatic vessels which pierce all organs. On the midwalls of vessels there are valves which hinder reverse motion of lymph. Lymphatic ganglions - filters of organism-- are located on motion a lymph.In lymphatic ganglions there are many limphocytes which take an active part in the imunnitive reactions of organism. All lymphatic vessels unite in channels and fall in veins. Therefore solution from tissues again goes back into blood.But it is mechanics only . If you want to know about work of the imunnitive system which is presented by limphatic organs, will ask me once again)