Lymph is called fluid that circulates through the lymphatic vessels. It is a colorless or slightly yellowish liquid composition similar to blood plasma. The lymph, together with the lymphatic vessels and lymph nodes, make up the lymphatic system, a very important part of the immune system.
Formation and composition
The lymph is formed by drainage of excess fluid coming out of the 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 driving organ like the heart in the blood circulation. The movement of the lymph occurs more slowly as it is pushed by the pulsations of the nearby arteries, muscle movements and movements of the extremities.
The composition of lymph is similar to blood plasma. It is a clear liquid, sometimes slightly yellowish, low in protein and rich in lipids 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 from the intestine
- fibrinogen
- lymphocytes
- cell debris
- metabolic waste
- germs
- cancer cells
Besides 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 a average adult there may be between 2 and 2.4 liters of lymph.
Functions
The 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 inside the lymph nodes. This network acts as a mesh that filters the lymph and here the lymphocytes have an easier time coming into contact and destroy bacteria, viruses, cancer cells and substances that may pose a threat to the body; lymph nodes and lymph, therefore, are part of the immune system.
In its metabolic role, lymph participates in the absorption of some nutrients in the intestinemainly long chain fatty acids. It also participates in the collection of interstitial fluid and its return to the blood circulation. Included in this collection are waste substances that the cells excrete to the interstitial medium and that through the lymph they pass into the blood circulation. 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, they can be done lymph node biopsies as well as studies of the lymph to look for pathogenic agents that cause a disease or for the diagnosis of some types of cancer.
Lymphatic drainage also explains, for example, why intramuscularly administered drugs and vaccines work: a substance is injected between the muscle tissue and is picked up by the lymph that slowly leads it towards the blood circulation.
The lymphatic massage It is a technique that requires Professional training and that pursues that the lymph drains and flows correctly to remove pathogens from a diseased area and thus promote health. When the lymph does not flow properly, the anterior body area can become swollen due to accumulation of interstitial fluid, which is known as edema. In addition to the liquid, toxins and waste accumulate; all this can cause pain, inflammation and influence other health problems.