How tissue fluid and lymph is formed: mechanisms
Of the three components, blood is the most intensely circulating fluid that nourishes the organs and tissues with oxygen and nutrients. To find out how tissue fluid and lymph are formed - the other two components of a given human environment - you need to turn to the school biology course.
These components form the drainage system, which contributes to the process of resorption (resorption) of organic substances and the further removal of metabolic products into the veins.
What is tissue fluid: composition, function and mechanism of formation
Tissue fluid is called the intermediate medium between the blood and the cells of the body. By chemical structure, it resembles plasma, because the formation of intercellular substance is associated with the process of filtering serum.
The blood, passing under high pressure through the small capillaries penetrating all tissues, is partially filtered through their thin, elastic walls.Due to this property of the blood, the liquid fraction from the plasma penetrates into the intercellular space, forming a tissue fluid. It washes the cells of all organs and tissues, which allows to transport nutrients to them and remove waste products.
Excessive pressure in the blood vessels provokes an increased accumulation of this substance between cells in local areas of the body. So there are swelling. The mechanism of how tissue fluid and lymph is formed is fairly simple, but the properties of these components of the internal environment are vital for humans.
Tissue fluid is colorless and transparent, contains water, amino acids, fatty acids, sugars, coenzymes, salts, mediators, hormones and metabolites. It found less protein than in plasma (less than 1.5 g / 100 ml), as well as other concentrations of enzymes and metabolic products. In various tissues, the intercellular substance has a different chemical composition. It varies due to the corresponding metabolism between the blood and tissue cells in a given area of the body. The amount of intercellular fluid in an adult ranges from 11 to 20 liters.
How lymph is formed, its properties
The constant exchange of liquids with substances dissolved in them in the internal environment between the blood moving through the capillaries, the tissue fluid, and also the lymph creates in the body a dynamic equilibrium (homeostasis).
At the initial stage, a part of the extracellular fluid, moving through the body, enters the lymphatic drainage system, in the vessels of which lymph is formed. This type of connective tissue is a colorless, viscous fluid with a high concentration of lymphocytes - cells that support the immune system.
After the lymph is formed, it moves through the vessels, passing through the lymph nodes, where it is enriched with protective cells. It is able not only to remove viruses from tissues, but also to maintain water balance in the body, as well as to ensure the continuous exchange of substances dissolved in the liquid fraction in almost all parts of the body. Scientists have observed the highest content of this liquid tissue in the organs where the capillaries have high permeability: in the heart and liver, spleen and skeletal muscle tissue.
The composition of the lymph and its functions
The above mechanism of formation of tissue fluid and lymph allows us to conclude that both of them have a common basis, since the second component of the internal environment is derived from the first.
In the lymph there is water (95%) and leukocytes, lymphocytes and metabolites - the elements formed as a result of the catabolism of organic compounds. The composition of this connective tissue also contains enzymes and vitamins. The lymph does not have platelets, but contains fibrinogen and other substances that increase blood clotting.
The amount of protein in the lymph is about 10 times less than in the blood (about 20 g / l). If the walls of the capillaries are damaged, the number of lymphocytes begins to increase automatically. The main objectives of the lymph are:
- return of tissue fluid to the circulatory system to maintain its constant volume and composition;
- transportation of protein into the blood;
- filtering of foreign particles and harmful microbes penetrating into the body;
- activation of fat absorption.
Lymph movement: volume and speed
After the tissue fluid and lymph is formed, about 2 ml of lymph per 1 kg of human weight (180-200 ml) flows into the vessels of the drainage system in an hour. During the day about 2 liters of connective fluid forms in the body of an adult.
Through the thoracic lymph flow, it can be pumped in a volume of up to 4 liters. To circulate this fluid, smooth muscle cells are built into the walls of the lymphatic vessels that can rhythmically contract.They move the lymph in a given direction.
Very important for the movement of connective fluid and the work of skeletal muscles in the contraction stage. During physical activity, the speed of movement of the lymph can increase by 15 times, compared with the same parameter at rest. Knowing how tissue fluid and lymph is formed, doctors often advise people who are prone to the appearance of edema, walk more in the open air, do regular exercises, and lead an active lifestyle.
Lymph congestion may be caused by mechanical, dynamic or resorption deficiency:
- In the first case, the blockage may be due to compression or malfunction of the valves of the lymph vessels.
- In the second, enhanced filtration of tissue fluid from the capillaries in a volume that the lymphatic system cannot process.
- In the third - biochemical and dispersed changes in tissue proteins, a decrease in the permeability of lymphocapillaries.
For those interested in the question of how tissue fluid and lymph is formed, we briefly repeat that tissue fluid is filtered from the plasma through the walls of the capillaries into the intercellular space.Part of this intermediate medium is returned to the blood, the other - enters the lymphatic vessels, which filter and disinfect it, and then transfer it to the venous bed. In the internal environment of the body, blood, tissue fluid and lymph provide a complex of the most complex adaptive reactions of a person to any effects.