Lymphatic vessel

A lymphatic vessel is an anatomical vessel and comparable to a blood vessel. However, it is not responsible for the transport of blood, but for the removal of tissue located in the liquid ( lymph ), including small amounts of proteins. In the lymphatic nodes are switched as a filter stations.

Anatomy

The lymphatic system can be broadly divided into four vessel types that differ from one another in structure, function and size:

• The lymphatic capillaries (also initial lymphatics ) begin finger -shaped intercellular space ( interstitium ) and consist of like roof tiles overlapping endothelial cells that form an approximately 50 microns large lumen. The lymphatic capillaries are fixed in the surrounding tissue with so-called Ankerfilamenten. These consist of microfibrils deposited on endothelial cells that bind to elastic fibers of the interstitial connective tissue. In addition to anchoring it cause the vessel lumen is kept open. In the lymph capillaries lymph formation takes place by absorption of the present in the interstitial tissue fluid. The lymphatic capillaries represents the smallest unit in the lymphatic system
• The lymph from several lymph united to the next larger lymphatic vessels, the precollectors. The precollectors carry lymph to the collectors. Take an intermediate position between lymphatic capillaries and collector, since they are involved in both the formation of lymph (ie, tissue fluid record ) and occasionally have muscle cells and thus can contract for propulsion of lymph.
• Several precollectors combine to form a collector. The collectors of the first set, only existing as the lymph transport lymph dar. The structure is similar to those of the veins having a three-layered wall structure and flaps similar to those in the venous blood vessels. By the flaps that are located at regular intervals ( approximately vessel diameter x 10), a back flow of lymph is prevented, thus ensuring a centrally directed lymph. The section between two flaps called lymphangion. Its designation as " Lymphherzchen " stems from the fact that the Angione at certain intervals contract (at rest about 10-12x/Minute ) and further squeeze the lymph in the next section. Be divided into the collectors: superficial collectors ( epifasziales system ): You are in the subcutaneous adipose tissue and take the lymph from the skin and the skin.
• Deep collectors ( subfasziales system ): You are within the fascia ( intrafaszial ) in the extremities and the trunk wall and take the lymph from muscles, ligaments, joints and bones.
• Viscera collectors ( visceral system ): take the lymph from the intestines.

Lymphatic vessels that lie in the same plane (eg superficial collectors in the subcutaneous fat tissue) are interconnected by so-called anastomoses. Lymphatic vessels, which lie in different planes (e.g., superficial and deep collectors) are connected to one another by so-called Perforanzgefäße.

Anastomoses are used among other things as diversions. If the lymph flow is interrupted in a larger vessel, the lymph flows through the anastomoses in an adjacent, connected with him, lymph vessel. Thus, a liquid accumulation and resultant lymphedema be avoided.

About the Perforanzgefäße There is a continuous flow of liquid, usually from the deep to the superficial lymphatics large instead (unlike the venous blood vessels where the blood flow usually deep runs from superficial after ). This property is made, inter alia, in the manual lymphatic drainage, a form of massage to benefit. Here the lymph flow of the superficial lymphatic vessels is supported and encouraged whereby the deep lymphatic vessels are better emptied by gentle massage.

Task

The lymphatic system is, among others, for the repatriation of stranded tissue fluid (ie not re- absorbed by the blood vascular system fluid) and protein molecules in the venous circulation responsible. Moreover, it has immunobiological tasks. As part of the digestion of fat, a major part of the absorbed from food grease is packed by the enterocytes of the small intestine in chylomicrons and transported via the lymph to the blood. Blockages in the lymphatic system or excessive demand the return transport capacity (eg venous congestion due to right heart failure ) have Lymphödembildungen result.

The protein transport back is important, because in accumulation of protein molecules in the interstitial colloid osmotic pressure would rise in the interstitium and increasing their efforts would that blood fluid from the capillaries passes into the interstitial space. This leads to a lack of volume ( hypovolemia ), at worst, a life-threatening shock.