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Lymph, or lymph, is a tissue fluid, more precisely a part of blood plasma filtered into peripheral tissues. What is the structure of the lymph? What are the functions of lymph in the human body?

Lymph , otherwiselymph(Latinlympha ), is the fluid circulating in the system lymphatic. The main task of the lymph in the human body is the transport of proteins and lymphocytes back from the tissues to the circulatory system.

Lymph circulates in the lymph vessels, which together with the lymph nodes and organs made of lymphoid tissue form the lymphatic (lymphatic) system.

Lymph (lymph) formation and circulation

Plasma is filtered through the walls of capillaries to organs and peripheral tissues. The lymph formed in them is the only way of the outflow of plasma proteins from the interstitial fluid into the circulatory system.

It is first transported with small, blind absorbent vessels, the so-called initial, which later turn into larger lymphatic vessels, the so-called collecting.

Their characteristic feature is the fact that they have valves that prevent the lymph from going back and enable its unidirectional flow, as well as smooth muscles in the vascular wall, which, by contracting, allow the lymph to flow in the right direction. The thoracic duct and the right lymphatic duct are the final drainage paths of the lymph into the venous system.

The vast majority of the produced lymph flows through the thoracic duct to the circulatory system. It drains lymph from the lower body, i.e. the lower and upper limbs, the abdominal cavity and the digestive tract, as well as from the left half of the head, neck and chest.

The right lymphatic duct receives lymph from the right side of the head, neck, and chest. The lymphatic vessels eventually enter the brachiocephalic veins, the thoracic duct connects to the circulatory system through the left subclavian vein, and the right lymphatic duct through the right subclavian vein.

Thanks to such interconnected systems, the previously filtered plasma proteins, lymphocytes and other components of the lymph find their way back into the bloodstream.

It is worth mentioning that the lymph flows in the lymph vessels thanks to three mechanisms: rhythmic contractions of large lymph vessels, contractions of skeletal muscles and negative pressure in the chest, andIts formation is influenced by, among others, nervous and hormonal factors, tissue hypoxia, ambient temperature, and other physical factors.

Lymph (lymph): chemical composition and functions

Lymph flowing through the lymphatic vessels does not have a uniform chemical composition. It is similar in composition to plasma, but contains much smaller amounts of proteins.

The main components of lymph are proteins, fats, cells of the immune system such as lymphocytes, as well as immunoglobulins and clotting factors.

It is worth noting, however, that the composition of the lymph may differ not only depending on the permeability of the local capillary wall and the functional state of the body, but also on the organ from which it is drained.

Lymph draining from the liver, heart, digestive tract and lungs has been shown to have the highest concentration of proteins.

Lymph and lymph vessels play an important role in the absorption of lipids in the digestive tract. They are the way fats in the form of chylomicrons pass from the intestines into the bloodstream, bypassing the liver.

The long-chain fatty acids and cholesterol absorbed in the gastrointestinal tract are transported with the help of the lymph flowing from the intestines, therefore, after a meal rich in fat, it takes on a cream color. This is due to the presence of large lipid particles.

Physiologically, the human body produces from two to four liters of lymph per day, but its amount is much greater (up to 4-15 times) and the outflow is more efficient in people with an active lifestyle.

Structure and functions of the lymphatic system

The main task of the lymphatic system is to transport some of the tissue fluid into the circulatory system. It consists of:

  • lymph vessels that are present in all tissues of the body, except the central nervous system, bone marrow, epidermis, cartilage, and also the cornea. They are part of the circulatory system and their main function is to drain excess tissue fluid back into the circulatory system.
  • lymph nodes that are located along the lymphatic system. The greatest accumulation of lymph nodes is in the groin, armpits, neck and abdominal cavity. They are part of the human immune system. It is there that T lymphocytes are produced and filtered into the lymphocytes. These are cells belonging to leukocytes, and their main task in the human body is to recognize and eliminate cells containing foreign antigens, such as viruses or bacteria. This is why lymph nodes get enlarged in response toan ongoing inflammatory process or infection. It is also worth noting that the lymphatic system is one of the ways of cancer metastasis, and the prognosis of patients and the method of treatment are often determined based on the inclusion of the disease in the surrounding lymph nodes.
  • lymphatic organs, which are made up of lymphatic tissue. These include the spleen, thymus, tonsils, and also the appendix.

Lymphedema

Lymphoedema is a chronic disease, the underlying cause of which is tissue edema, resulting from an abnormal, insufficient outflow of lymph from the tissues. The main cause of lymphoedema is damage to the lymphatic vessels.

After compression and reduction of lumen flow or complete closure of the lymphatic vessel, intercellular fluid accumulates below the closed segment, which leads to tissue edema, most often skin and subcutaneous tissue, and causes a chronic inflammatory process.

The main symptom of lymphatic stagnation in tissues is a depression on the surface of the skin after pressing it with a finger (the so-called pasty swelling). Over time, the skin and subcutaneous tissue harden and are no longer susceptible to pressure.

The most common causes of lymphoedema include:

  • iatrogenic edema - complications of surgical procedures in which the removal of the lymph nodes was necessary (e.g. breast cancer surgery involving the local lymph nodes); in such a situation, the lymph flow is slower and slower, which results in the accumulation of tissue fluid in the upper limb on the side of the operated mammary gland
  • neoplastic infiltrates compressing lymphatic vessels in advanced stages of neoplastic disease
  • parasitic diseases, which include filariosis - it is a disease that affects mainly people living in Asia or traveling to those regions, and consists in the entry of parasites from the group of nematodes into the human body; their specific feature is the movement of the lymphatic vessels through the lymphatic vessels - they cause a difficult outflow of lymph from the surrounding tissues, the accumulation of tissue fluid and, consequently, the formation of lymphoedema
  • inflammation of the skin, vessels and lymph nodes
  • connective tissue diseases such as systemic scleroderma, rheumatoid arthritis or psoriatic arthritis
  • traumatic damage to the lymphatic vessels

Physiotherapy is the basic method of treating lymphoedema.

  • Who is the physiotherapist?

The most commonly used treatment methods are lymphatic drainage techniques, compression bandaging, and pressure gymnastics.

Pharmacological treatment is not considered effective, and surgical procedures are used only in exceptional cases. The prognosis for curing the patient is not favorable.

Słoniowacizna

Elephantiasis is a significant lymphoedema of the tissues that leads to the deformation of the affected area. It is formed as a result of long-term accumulation of tissue fluid and lymph stasis, most often in the upper and lower limbs and the perineum.

This condition may be congenital (lack of lymphatic vessels in a specific area of ​​the body) or acquired (as a result of damage to lymphatic vessels during, among others, surgery, radiotherapy, cancer process).

It is characterized by the occurrence of permanent, irreversible changes in the form of a huge swelling that makes it impossible to function and move, hardening of the skin and the appearance of bulges and growths within the affected area, ending with sensory disturbances and degenerative changes in the osteoarticular system.

The affected skin is dry, calloused, tight, shiny, prone to cracks and the formation of difficult-to-heal erosions and ulcers, which become the gateway of infection.

Despite treatment, the affected limb most often does not return to its original shape. Sometimes the only method of therapy is surgical treatment, even ending with the amputation of the affected limb.

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Immune system