Lymph is called fluid that circulates through lymphatic vessels. It is a colorless or slightly yellowish liquid similar to blood plasma. Lymph, along with lymph vessels and lymph nodes, form the lymphatic system, a very important part of the immune system.
Formation and composition
Lymph is formed by draining excess fluid from blood vessels into the interstitial and intercellular space. This excess is collected by the lymphatic capillaries, small vessels that drain into larger vessels that eventually lead to channels that empty into the subclavian veins.
in the lymphatic circulation there is no conduction organ like the heart in the blood circulation. Lymph movement occurs more slowly as it is pushed by pulsations from nearby arteries, muscle movements and movements of the extremities.
The composition of lymph is similar to blood plasma. It is a clear, sometimes slightly yellowish, low-protein, lipid-rich liquid that does not contain red blood cells. Among the main substances that we can find in the lymph are:Various plasma proteins Lipids, mainly long-chain fatty acids that are absorbed in the intestine fibrinogen lymphocytes Cell debris metabolic waste germs cancer cells
In addition to lymphocytes, which represent 99% of the cells that can be found in lymph, we can find other leukocytes such as macrophages and granulocytes. These cells, very important in the immune system, are formed from the lymphoid cells of the bone marrow.
The amount of lymph in the human body is variable and largely depends on the amount of blood. It is estimated that in an average adult there can be between 2 and 2.4 liters of lymph.
Lymph has mainly two functions, an immune function and a metabolic function.
Lymphocytes make up 99% of lymph cells and can be found in large numbers in the connective tissue network within lymph nodes. This network works like a mesh that filters the lymph and here lymphocytes have an easier time getting in contact and destroying bacteria, viruses, cancer cells and substances that can pose a threat to the body; lymph nodes and lymph are therefore part of the immune system.
In its metabolic role, lymph participates in the absorption of some nutrients in the intestine, mainly long-chain fatty acids. It also participates in the collection of interstitial fluid and its return to the bloodstream. Included in this collection are residual substances that the cells excrete into the interstitial environment and that pass through the lymph into the bloodstream. Through the circulatory system they will be eliminated by various routes, for example urine.
As a biological fluid, lymph is useful in some diagnostic tests. For example, lymph node biopsies as well as lymph studies can be done to look for disease-causing pathogens or for the diagnosis of some types of cancer.
Lymphatic drainage also explains, for example, why drugs and vaccines given intramuscularly work: a substance is injected between muscle tissue and is picked up by the lymph, which slowly carries it into the bloodstream.
o Lymphatic massage It is a technique that requires professional training and seeks to ensure that the lymph drains and flows correctly to remove pathogens from a diseased area and thus promote health. When lymph does not flow properly, the anterior area of the body can become swollen due to the buildup of interstitial fluid, known as edema. In addition to the liquid, toxins and waste accumulate; all of these can cause pain, inflammation and influence other health problems.