Lymphatic vessels. They are structures within the lymphatic system . They transport the lymph from the tissues to the superior vena cava, collecting excess liquids, to avoid congestion.
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- 1 function
- 3 types of lymphatic vessels
- 4 Sources
Transport lymph —a clear fluid that is 90% water, protein molecules, salts, fats, lipids, lymphocytes, and other substances— from the tissues throughout the body. They are present in almost the entire body, with the exception of the Central Nervous System , bone marrow and cartilage .
- They are open at one end that communicates with a vein or artery.
- They communicate with each other, forming a network of small vessels called lymphatic capillaries. This structure is found in loose connective tissue. They differ from blood capillaries in that they begin in the tissues, have a blind end, and have more permeable walls. On their way, the lymphatic capillaries join each other to form thicker lymphatic vessels. The thoracic duct is the largest lymphatic vessel in the body; It is responsible for collecting the lymph that comes from the vessels throughout the body, with the exception of the upper right area, which is collected by the right lymphatic vessel and deposited in the right subclavian vein and empties it into the left subclavian vein.
- Internally they contain semilunar valves, which allow the movement of the lymphonly in one direction, that is, these valves open when the lymph goes to the heart and close when this liquid wants to go back, thus avoiding reflux.
- The lymph nodesare a kind of tiny encapsulated nodules, which purify the lymph before incorporating it back into the blood. They filter the lymph to eliminate toxins and also produce antibodies, which is why they are an important part of the immune system, thanks to the lymphocytes. They have a size between 0.5 and 1 cm.
- The circulation of the lymph is slower than that of the blood, since it is only driven by the muscles that surround the lymphatic vessels.
- The lymphatic heart or lymphangion is the segment within the lymphatic vessels, located between the two valves.
- The thoracic duct.
types of lymphatic vessels
- Afferent lymphatic vessels: carry lymph within a lymph node.
- Efferent lymphatic vessels: transport lymph out of the lymph node. From the latter, the lymph may travel to another lymph node, return to a vein, or be transported to a larger lymphatic duct. The lymphatic ducts drain the lymph into one of the subclavian veins and thus returns to the general circulation.