home Auditorium 8 What function does the lymphatic system perform? Diagram of the direction of movement of lymph in the human lymphatic system. Main lymphatic collectors

What function does the lymphatic system perform? Diagram of the direction of movement of lymph in the human lymphatic system. Main lymphatic collectors

Lymphatic system – an integral part of the vascular system, which drains tissues through the formation of lymph and conducts it into the venous bed (additional drainage system).

Up to 2 liters of lymph are produced per day, which corresponds to 10% of the volume of fluid that is not reabsorbed after filtration in the capillaries.

Lymph is the fluid that fills the lymphatic vessels and nodes. It, like blood, belongs to the tissues of the internal environment and performs trophic and protective functions in the body. In its properties, despite its great similarity with blood, lymph differs from it. At the same time, lymph is not identical to the tissue fluid from which it is formed.

Lymph consists of plasma and formed elements. Its plasma contains proteins, salts, sugar, cholesterol and other substances. The protein content in lymph is 8-10 times less than in blood. 80% of the formed elements of lymph are lymphocytes, and the remaining 20% are other white blood cells. There are normally no red blood cells in lymph.

Functions of the lymphatic system:

Tissue drainage.

Ensuring continuous circulation of fluid and metabolism in human organs and tissues. Prevents the accumulation of fluid in the tissue space with increased filtration in the capillaries.

Lymphopoiesis.

Transports fats from the site of absorption in the small intestine.

Removal from the interstitial space of substances and particles that are not reabsorbed in the blood capillaries.

Spread of infection and malignant cells (tumor metastasis)

Factors ensuring lymph movement

Filtration pressure (caused by the filtration of fluid from blood capillaries into the intercellular space).

Constant formation of lymph.

Availability of valves.

Contraction of surrounding skeletal muscles and muscular elements of internal organs (lymphatic vessels are compressed and lymph moves in the direction determined by the valves).

The location of large lymphatic vessels and trunks near blood vessels (the pulsation of the artery compresses the walls of the lymphatic vessels and helps the flow of lymph).

Suction action of the chest and negative pressure in the brachiocephalic veins.

Smooth muscle cells in the walls of lymphatic vessels and trunks .

Table 7

Similarities and differences in the structure of the lymphatic and venous systems

Lymphatic capillaries– thin-walled vessels, the diameter of which (10-200 microns) exceeds the diameter of blood capillaries (8-10 microns). Lymphatic capillaries are characterized by tortuosity, the presence of narrowings and expansions, lateral protrusions, the formation of lymphatic “lakes” and “lacunae” at the confluence of several capillaries.

The wall of the lymphatic capillaries is built from a single layer of endothelial cells (in the blood capillaries there is a basement membrane outside the endothelium).

Lymphatic capillaries No in the substance and membranes of the brain, cornea and lens of the eyeball, spleen parenchyma, bone marrow, cartilage, epithelium of the skin and mucous membranes, placenta, pituitary gland.

Lymphatic postcapillaries– an intermediate link between lymphatic capillaries and vessels. The transition of the lymphatic capillary to the lymphatic postcapillary is determined by the first valve in the lumen (the valves of the lymphatic vessels are paired folds of the endothelium and the underlying basement membrane lying opposite each other). Lymphatic postcapillaries have all the functions of capillaries, but lymph flows through them only in one direction.

Lymphatic vessels are formed from networks of lymphatic postcapillaries (capillaries). The transition of a lymphatic capillary into a lymphatic vessel is determined by a change in the structure of the wall: along with the endothelium, it contains smooth muscle cells and adventitia, and in the lumen there are valves. Therefore, lymph can flow through the vessels only in one direction. The area of the lymphatic vessel between the valves is currently designated by the term "lymphangion" (Fig. 58).

Rice. 58. Lymphangion is a morphofunctional unit of a lymphatic vessel:

1 – segment of the lymphatic vessel with valves.

Depending on the location above or below the superficial fascia, lymphatic vessels are divided into superficial and deep. Superficial lymphatic vessels lie in the subcutaneous fat above the superficial fascia. Most of them go to the lymph nodes located near the superficial veins.

There are also intraorgan and extraorgan lymphatic vessels. Due to the existence of numerous anastomoses, intraorgan lymphatic vessels form wide-loop plexuses. The lymphatic vessels emerging from these plexuses accompany the arteries, veins and exit the organ. Extraorgan lymphatic vessels are directed to nearby groups of regional lymph nodes, usually accompanying blood vessels, often veins.

Along the path of the lymphatic vessels there are The lymph nodes. This is what causes foreign particles, tumor cells, etc. are retained in one of the regional lymph nodes. The exceptions are some lymphatic vessels of the esophagus and, in isolated cases, some vessels of the liver, which flow into the thoracic duct, bypassing the lymph nodes.

Regional lymph nodes organs or tissues are lymph nodes that are the first on the path of lymphatic vessels carrying lymph from a given area of the body.

Lymphatic trunks- These are large lymphatic vessels that are no longer interrupted by lymph nodes. They collect lymph from several areas of the body or several organs.

There are four permanent paired lymphatic trunks in the human body.

Jugular trunk(right and left) is represented by one or several vessels of small length. It is formed from the efferent lymphatic vessels of the lower lateral deep cervical lymph nodes, located in a chain along the internal jugular vein. Each of them drains lymph from the organs and tissues of the corresponding sides of the head and neck.

Subclavian trunk(right and left) is formed from the fusion of the efferent lymphatic vessels of the axillary lymph nodes, mainly the apical ones. It collects lymph from the upper limb, from the walls of the chest and mammary gland.

Bronchomediastinal trunk(right and left) is formed mainly from the efferent lymphatic vessels of the anterior mediastinal and superior tracheobronchial lymph nodes. It carries lymph away from the walls and organs of the chest cavity.

The efferent lymphatic vessels of the upper lumbar lymph nodes form the right and left lumbar trunks, which drain lymph from the lower limb, walls and organs of the pelvis and abdomen.

A non-permanent intestinal lymphatic trunk occurs in approximately 25% of cases. It is formed from the efferent lymphatic vessels of the mesenteric lymph nodes and 1-3 vessels flow into the initial (abdominal) part of the thoracic duct.

Rice. 59. Basin of the thoracic lymphatic duct.

1 – superior vena cava;

2 – right brachiocephalic vein;

3 – left brachiocephalic vein;

4 – right internal jugular vein;

5 – right subclavian vein;

6 – left internal jugular vein;

7 – left subclavian vein;

8 – azygos vein;

9 – hemizygos vein;

10 – inferior vena cava;

11 – right lymphatic duct;

12 – cistern of the thoracic duct;

13 – thoracic duct;

14 – intestinal trunk;

15 – lumbar lymphatic trunks

The lymphatic trunks flow into two ducts: the thoracic duct (Fig. 59) and the right lymphatic duct, which flow into the veins of the neck in the area of the so-called venous angle, formed by the connection of the subclavian and internal jugular veins. The thoracic lymphatic duct flows into the left venous angle, through which lymph flows from 3/4 of the human body: from the lower extremities, pelvis, abdomen, left half of the chest, neck and head, left upper extremity. The right lymphatic duct flows into the right venous angle, which brings lymph from 1/4 of the body: from the right half of the chest, neck, head, and from the right upper limb.

Thoracic duct (ductus thoracicus) has a length of 30-45 cm, is formed at the level of the XI thoracic – 1st lumbar vertebrae by the fusion of the right and left lumbar trunks (trunci lumbales dexter et sinister). Sometimes at the beginning the thoracic duct has extension (cisterna chyli). The thoracic duct is formed in the abdominal cavity and passes into the chest cavity through the aortic opening of the diaphragm, where it is located between the aorta and the right medial crus of the diaphragm, the contractions of which help push lymph into the thoracic part of the duct. At the level of the VII cervical vertebra, the thoracic duct forms an arc and, going around the left subclavian artery, flows into the left venous angle or the veins that form it. At the mouth of the duct there is a semilunar valve that prevents blood from entering the duct from the vein. The left bronchomediastinal trunk (truncus bronchomediastinalis sinister), which collects lymph from the left half of the chest, flows into the upper part of the thoracic duct, as well as the left subclavian trunk (truncus subclavius sinister), which collects lymph from the left upper limb and the left jugular trunk (truncus jugularis sinister), which carries lymph from the left half of the head and neck.

Right lymphatic duct (ductus lymphaticus dexter) 1-1.5 cm long, is being formed at the fusion of the right subclavian trunk (truncus subclavius dexter), carrying lymph from the right upper limb, the right jugular trunk (truncus jugularis dexter), collecting lymph from the right half of the head and neck, the right bronchomediastinal trunk (truncus bronchomediastinalis dexter), bringing lymph from the right half of the chest. However, more often the right lymphatic duct is absent, and the trunks that form it flow into the right venous angle independently.

Lymph nodes of individual areas of the body.

Head and neck

In the head area there are many groups of lymph nodes (Fig. 60): occipital, mastoid, facial, parotid, submandibular, submental, etc. Each group of nodes receives lymphatic vessels from the area closest to its location.

Thus, the submandibular nodes lie in the submandibular triangle and collect lymph from the chin, lips, cheeks, teeth, gums, palate, lower eyelid, nose, submandibular and sublingual salivary glands. Lymph flows from the forehead, temple, upper eyelid, auricle, and walls of the external auditory canal into the parotid lymph nodes, located on the surface and in the thickness of the gland of the same name.

Fig.60. Lymphatic system of the head and neck.

1 – anterior ear lymph nodes; 2 – posterior ear lymph nodes; 3 – occipital lymph nodes; 4 – lower ear lymph nodes; 5 – buccal lymph nodes; 6 – mental lymph nodes; 7 – posterior submandibular lymph nodes; 8 – anterior submandibular lymph nodes; 9 – lower submandibular lymph nodes; 10 – superficial cervical lymph nodes

There are two main groups of lymph nodes in the neck: deep and superficial cervical. Deep cervical lymph nodes accompany the internal jugular vein in large numbers, and superficial ones lie near the external jugular vein. In these nodes, mainly in the deep cervical nodes, there is an outflow of lymph from almost all the lymphatic vessels of the head and neck, including the efferent vessels of other lymph nodes in these areas.

Upper limb

There are two main groups of lymph nodes in the upper limb: ulnar and axillary. The ulnar nodes lie in the cubital fossa and receive lymph from some of the vessels of the hand and forearm. Through the efferent vessels of these nodes, lymph flows into the axillary nodes. The axillary lymph nodes are located in the fossa of the same name, one part of them lies superficially in the subcutaneous tissue, the other in the depths near the axillary arteries and veins. Lymph flows into these nodes from the upper limb, as well as from the mammary gland, from the superficial lymphatic vessels of the chest and the upper part of the anterior abdominal wall.

Thoracic cavity

In the chest cavity, the lymph nodes are located in the anterior and posterior mediastinum (anterior and posterior mediastinal), near the trachea (peritracheal), in the area of the tracheal bifurcation (tracheobronchial), at the gates of the lung (bronchopulmonary), in the lung itself (pulmonary), and also on the diaphragm (upper diaphragmatic), near the heads of the ribs (intercostal), near the sternum (periosternal), etc. Lymph flows from the organs and partially from the walls of the chest cavity into these nodes.

Lower limb

On the lower limb, the main groups of lymph nodes are popliteal and inguinal. The popliteal nodes are located in the fossa of the same name near the popliteal artery and vein. These nodes receive lymph from part of the lymphatic vessels of the foot and leg. The efferent vessels of the popliteal nodes carry lymph mainly to the inguinal nodes.

Inguinal lymph nodes are divided into superficial and deep. The superficial inguinal nodes lie below the inguinal ligament under the skin of the thigh on top of the fascia, and the deep inguinal nodes lie in the same area, but under the fascia near the femoral vein. Lymph flows into the inguinal lymph nodes from the lower limb, as well as from the lower half of the anterior abdominal wall, perineum, from the superficial lymphatic vessels of the gluteal region and lower back. From the inguinal lymph nodes, lymph flows into the external iliac nodes, which are related to the pelvic nodes.

In the pelvis, the lymph nodes are located, as a rule, along the blood vessels and have a similar name (Fig. 61). Thus, the external iliac, internal iliac and common iliac nodes lie near the arteries of the same name, and the sacral nodes lie on the pelvic surface of the sacrum, near the median sacral artery. Lymph from the pelvic organs flows mainly into the internal iliac and sacral lymph nodes.

Rice. 61. Lymph nodes of the pelvis and the vessels connecting them.

1 – uterus; 2 – right common iliac artery; 3 – lumbar lymph nodes; 4 – iliac lymph nodes; 5 – inguinal lymph nodes

Abdominal cavity

There are a large number of lymph nodes in the abdominal cavity. They are located along the blood vessels, including the vessels passing through the hilum of the organs. So, along the abdominal aorta and inferior vena cava near the lumbar spine there are up to 50 lymph nodes (lumbar). In the mesentery of the small intestine, along the branches of the superior mesenteric artery, there are up to 200 nodes (superior mesenteric). There are also lymph nodes: celiac (near the celiac trunk), left gastric (along the greater curvature of the stomach), right gastric (along the lesser curvature of the stomach), hepatic (in the area of the hilum of the liver), etc. Lymph from the organs flows into the lymph nodes of the abdominal cavity. located in this cavity, and partly from its walls. The lumbar lymph nodes also receive lymph from the lower extremities and pelvis. It should be noted that the lymphatic vessels of the small intestine are called lacteal, since lymph flows through them, containing fat absorbed in the intestine, which gives the lymph the appearance of a milky emulsion - hilus (hilus - milky juice).

The part of the vascular system that frees body tissues from metabolic products, infectious agents and their toxins is called lymphatic. It contains vessels, nodes, ducts, as well as organs involved in the formation of lymphocytes.

With insufficient immune protection, tumor and microbial cells can spread along the lymphatic pathways. Stagnation of lymph leads to the accumulation of excretory products in tissues. To improve the drainage function of the lymphatic system, massage and special cleaning methods are prescribed.

Read in this article

The lymphatic system includes capillary, intraorgan and stem vessels, nodes and lymphatic organs.

Vessels

Inside the organs there is a network of small lymphatic capillaries; they have very thin walls, through which large particles of protein and liquid easily penetrate from the intercellular space. Subsequently, they unite into vessels similar to veins, but with more permeable membranes and a developed valve apparatus.

Vessels from organs carry lymph to the nodes. In appearance, the lymphatic network is similar to beads. This structure arises due to alternating areas of narrowing and widening at the site of attachment of the semilunar valves. The penetration of tissue fluid into the capillaries is explained by the difference in osmotic pressure (lymph is more concentrated), and the reverse flow is impossible due to the valves.

Nodes

They have many incoming vessels and 1 or 2 outgoing vessels. The shape is similar to a bean or a ball about 2 cm. They filter the lymphatic fluid, retain and inactivate toxic substances and microbes, and the lymph is saturated with cells of the immune system - lymphocytes.

The fluid that moves through the lymphatic vessels has a whitish or yellowish color. Its composition depends on the organ from which it comes.

The following elements penetrate the lymph:

water;
proteins (large molecules);
destroyed and tumor cells;
bacteria;
dust and smoke particles from the lungs;
fluid from the abdominal cavity, pleura and pericardium, joints;
any foreign particles.

Basic functions in the body

The biological role of the lymphatic system is associated with the following areas of activity:

the formation of lymphocytes responsible for cellular and humoral (with the help of special blood proteins) immunity;
retention of mechanical impurities, microbes and toxic compounds in the lymph node;
return of purified blood to the venous vessels;
transfer of fats from the intestinal lumen into the blood;
additional tissue drainage to reduce swelling;
absorption of large protein molecules from tissue fluid, which themselves cannot enter the blood vessels due to their size.

Watch the video about the human lymphatic system and its functions:

Lymph movement pattern

The initial absorption of tissue fluid occurs in organs through lymphatic capillaries. The resulting lymph enters the nodes through a network of vessels. Purified and saturated with lymphocytes, the fluid from the lymph node moves into the trunks and ducts. There are only two of them in the body:

thoracic - collects lymph from the left upper limb, left side of the head, chest and all parts of the body lying under the diaphragm;
right – contains fluid from the right arm, half of the head and chest.

The ducts carry lymph to the left and right subclavian veins. It is at the level of the neck that the lymphovenous anastomosis is located, through which the lymphatic fluid penetrates into the venous blood.

To promote lymph, the simultaneous action of the following factors is required:

the pressure of the liquid that is formed in a continuous mode;
contraction of the smooth muscles of the blood vessels between the two valves - the muscular cuff (lymphangion);
vibrations of the walls of arteries and veins;
compression by muscles during body movements;
suction effect of the chest during breathing.

Organs of the lymphatic system

Lymphoid tissue is found in various structures. What they have in common is that they all serve as a site for the formation of lymphocytes:

the thymus is located behind the sternum, ensures the maturation and “specialization” of T-lymphocytes;
bone marrow is found in the tubular bones of the limbs, pelvis, ribs, and contains immature stem cells, from which blood cells are subsequently formed;
pharyngeal tonsils are located in the nasopharyngeal region, protect against microbes, and participate in hematopoiesis;
the appendix extends from the initial part of the large intestine, cleanses lymph, forms enzymes, hormones and bacteria involved in the digestion of food;
the spleen is the largest organ of the lymphatic system, adjacent to the stomach in the left half of the abdominal cavity, acts as a filter for bacteria and foreign particles, produces antibodies, lymphocytes and monocytes, regulates the functioning of the bone marrow;
lymph nodes of internal organs (single or clusters) take part in the formation of cells for immune defense - T and B lymphocytes.

Types and groups of diseases

In diseases of the lymphatic system, inflammatory processes may occur:

lymphangitis – capillaries, vessels and trunks in contact with the source of suppuration are affected;
lymphadenitis - the lymph nodes are involved, the infection penetrates with the lymph or directly through the skin (mucous) in case of injury.

Damages to the organs of the lymphatic system can manifest themselves in the form of tonsillitis due to infection of the tonsils, appendicitis (inflammation of the appendix, appendix). Pathological changes in the thymus lead to muscle weakness, autoimmune processes, and tumors.

Bone marrow dysfunction causes various changes in blood composition: cell deficiency with decreased immunity (), coagulation (), oxygen supply (anemia), malignant blood tumors.

An enlarged spleen (splenomegaly) occurs with diseases of the blood, liver, and typhoid fever. An abscess or cyst may also form in the tissue.

Stagnation of lymphatic fluid leads to the development of lymphedema (lymphoedema). It occurs when there is an obstruction in the vessels of a congenital (structural anomaly) or acquired nature. Secondary lymphedema accompanies injuries, burns, infections, and surgical interventions. As lymphostasis progresses, elephantiasis of the lower extremities occurs, requiring surgery.

Elephantiasis of the lower extremities

Tumor processes in which lymphatic vessels are involved are more often benign. They are called lymphangiomas. They are found on the skin, in the subcutaneous layer, as well as in places where lymphoid tissue accumulates - neck, head, chest, abdominal cavity, inguinal and axillary areas. When malignancy occurs, lymphosarcoma is located in the same areas.

Causes of disorders in the body

Inflammatory and tumor processes occur when the immune system is disrupted, when it ceases to cope with the body’s defense function. This may be a consequence of external factors:

Chronic foci of infection in the body, as well as poor function of the excretory organs, contribute to excess load on the lymphatic system. The result is a decrease in its basic functions. Of no small importance for lymph flow is the state of the circulatory system, of which the lymphatic is a part.

Stagnant processes occur in the following pathological conditions:

circulatory failure - arterial (weakness of cardiac activity) and venous (,);
physical inactivity, obesity;
diseases of the kidneys, liver, intestines;
congenital anomalies of the development of organs of the lymphatic system;
injuries and operations, burns.

Symptoms of the onset of diseases

When the movement of lymph is disrupted, swelling occurs in the lower extremities, especially after intense exercise. If treatment is not carried out at this stage, tissue swelling (lymphedema) becomes dense, heaviness in the legs, cramps and pain occurs.

Inflammatory diseases of the vessels and nodes of the lymphatic system manifest themselves in the form of regional redness, swelling and thickening of the skin. This is accompanied by high fever, chills and headache. With deep lymphangitis, there are no external manifestations, but the affected area increases in volume due to tissue swelling. Lymph nodes with lymphadenitis become painful, dense, and can be easily felt.

Submandibular lymphadenitis

Diagnosis of the condition

In order to examine the patency of lymphatic vessels and the area of blocked outflow, the following methods are used:

Lymphography with X-ray control, CT or MRI determines valvular insufficiency and structural anomalies. A normal lymphogram has the appearance of uneven accumulations of contrast material in the form of beads.
Lymphoscintigraphy with technetium makes it possible to detect foci of radioisotope concentration in the area of lymph stagnation.
Ultrasound with – areas of vasoconstriction, changes in nodes.
Computer thermography is used for differential diagnosis with phlegmon, phlebitis and osteomyelitis.
Lymph node biopsy - reveals blood tumors and cancer metastases.
Blood tests - during inflammation, leukocytosis is noted; with culture, the causative agent of the infection can be determined.

If tuberculosis is suspected, tuberculin tests (Mantoux) and chest x-ray are performed.

Treatment Options

In the initial stages of lymph stagnation, predominantly non-drug methods are used - massage, magnetic therapy, wearing compression stockings. A good effect has been obtained from mechanical pneumocompression and laser treatment for diseases of the lymphatic vessels.

For severe lymphedema, the following is prescribed:

phlebotonics (Detralex, Cyclo-3-fort, Aescin);
enzymes – Wobenzym, Trypsin;
angioprotectors – Trental, Quercetin;
– Lasix, Trifas (no more than 2 - 3 days).

If there is a threat of sepsis, then ultraviolet irradiation of the blood can be used. At the stage of resorption or with low-grade inflammation, local compresses, dressings with Dimexide, Dioxidin, Chymotrypsin, and mud treatment are indicated.

The progression of lymph stagnation with the formation of elephantiasis of the extremities is treated by creating outflow tracts during microsurgical operations.

How to cleanse the lymphatic system

To improve the movement of lymph in the body, traditional medicine and massage techniques are used. An important condition for the prevention of diseases is the motor regime - the load should be at least 30 minutes; regular walking in nature and breathing exercises have a healing effect.

To accelerate the removal of metabolic products from the body and neutralize toxic compounds, use:

sauna (steam room, bathhouse);
a bath with warm water and sea salt;
saturating tissues with clean water;
restriction of dairy, meat products, white bread, starch;
juices from cherries, blackberries, grapes, cranberries;
fresh beet and red cabbage salad with lemon;
adding parsley and dill, lettuce and fresh garlic to food;
herbal tea from clover, elderflower, nettle (a teaspoon of one of the herbs in a glass of boiling water three times a day);
tincture of echinacea or eleutherococcus, 15 drops in the morning;
chicory instead of coffee;
spices – ginger, turmeric, fennel;
instead of sweets - currants, blackberries, lingonberries and blueberries;
tincture similar to Swedish bitters - 10 g of juice from aloe leaves, a tablespoon of wormwood, rhubarb and senna leaves, on the tip of a knife - turmeric and saffron. Pour a liter of vodka and leave for 15 days. Drink a teaspoon with tea.

Impact of massage

Lymphatic drainage is enhanced by stroking the lymph flow. Since its movement occurs only from bottom to top, the massage movements should have a similar direction.

In this case, the following changes occur in tissues:

the movement of fluid from tissues into lymphatic capillaries accelerates;
swelling decreases,
Metabolic products are eliminated faster.

Pressure and compression work deeper into soft tissues, and vibration helps to enhance microcirculation. Massage is contraindicated in any acute process in the body, and especially in the presence of a purulent focus, since in these cases accelerated lymph flow will lead to the spread of damage to other organs and tissues.

The lymphatic system has a drainage function, participates in metabolic processes and the formation of cells of the immune system. When overexertion occurs (due to external factors or against the background of diseases), a malfunction of the immune system occurs, which contributes to inflammatory or tumor processes.

Antibacterial drugs, venotonics, and angioprotectors can be used for treatment. In severe cases, surgery is indicated. To cleanse the lymphatic system, you need to adjust your diet, move as much as possible, drink herbal teas, and undergo a course of lymphatic drainage massage.

Factors ensuring lymph movement

Filtration pressure (caused by the filtration of fluid from blood capillaries into the intercellular space).

Constant formation of lymph.

Availability of valves.

Contraction of surrounding skeletal muscles and muscular elements of internal organs (lymphatic vessels are compressed and lymph moves in the direction determined by the valves).

The location of large lymphatic vessels and trunks near blood vessels (the pulsation of the artery compresses the walls of the lymphatic vessels and helps the flow of lymph).

Suction action of the chest and negative pressure in the brachiocephalic veins.

Smooth muscle cells in the walls of lymphatic vessels and trunks .

Table 7

Similarities and differences in the structure of the lymphatic and venous systems

The wall of the lymphatic capillaries is built from a single layer of endothelial cells (in the blood capillaries there is a basement membrane outside the endothelium).

Rice. 58. Lymphangion is a morphofunctional unit of a lymphatic vessel:

1 – segment of the lymphatic vessel with valves.

Regional lymph nodes organs or tissues are lymph nodes that are the first on the path of lymphatic vessels carrying lymph from a given area of the body.

Lymphatic trunks- These are large lymphatic vessels that are no longer interrupted by lymph nodes. They collect lymph from several areas of the body or several organs.

There are four permanent paired lymphatic trunks in the human body.

The efferent lymphatic vessels of the upper lumbar lymph nodes form the right and left lumbar trunks, which drain lymph from the lower limb, walls and organs of the pelvis and abdomen.

Rice. 59. Basin of the thoracic lymphatic duct.

1 – superior vena cava;

2 – right brachiocephalic vein;

3 – left brachiocephalic vein;

4 – right internal jugular vein;

5 – right subclavian vein;

6 – left internal jugular vein;

7 – left subclavian vein;

8 – azygos vein;

9 – hemizygos vein;

10 – inferior vena cava;

11 – right lymphatic duct;

12 – cistern of the thoracic duct;

13 – thoracic duct;

14 – intestinal trunk;

15 – lumbar lymphatic trunks

Lymph nodes of individual areas of the body.

Head and neck

Fig.60. Lymphatic system of the head and neck.

Upper limb

Thoracic cavity

Lower limb

Rice. 61. Lymph nodes of the pelvis and the vessels connecting them.

1 – uterus; 2 – right common iliac artery; 3 – lumbar lymph nodes; 4 – iliac lymph nodes; 5 – inguinal lymph nodes

Abdominal cavity

If we talk about the work of the body and in particular about the fluids that flow in the body, then not many people immediately name lymph.

However, lymph has great value for the body and has very significant functions that allow the body to function normally.

What is the lymphatic system?

Many people know about the body's need for blood circulation and the functioning of other systems, but not many know about the high importance of the lymphatic system. If lymph does not circulate throughout the body for just a couple of hours, then such an organism can no longer function.

Thus, every human body experiences continuous need in the functioning of the lymphatic system.

It is easiest to compare the lymphatic system with the circulatory system and distinguish the following differences:

Openness, unlike the circulatory system, the lymphatic system is open, that is, there is no circulation as such.
Unidirectionality, if the circulatory system provides movement in two directions, then the lymph moves in the direction only from the peripheral to the central parts of the system, that is, the liquid first collects in the smallest capillaries and then moves into larger vessels, and the movement occurs only in this direction.
There is no central pump. In order to ensure the movement of fluid in the desired direction, only a valve system is used.
More slow motion fluids compared to the circulatory system.
The presence of special anatomical elements– lymph nodes, which perform a significant function and are a kind of warehouse for lymphocytes.

The lymphatic vascular system is of greatest importance for metabolism and providing immunity. It is in the lymph nodes that the bulk of foreign elements that enter the body are processed.

If there is any virus in the body, then it is in the lymph nodes that work begins to study and displace this virus from the body.

You yourself can notice this activity when you have signs that indicate the body's fight against the virus. In addition, lymph regularly cleanses the body and removes unnecessary elements from the body.

Learn more about the lymphatic system from the video:

Functions

If we talk in more detail about the functions, we should note the connection between the lymphatic system and the cardiovascular system. It is thanks to lymph that the delivery of various items, which cannot immediately end up in the cardiovascular system:

proteins;
fluid from tissue and intertissue space;
fats that come mainly from the small intestine.

These elements are transported to the venous bed and thus end up in the circulatory system. These components can then be removed from the body.

At the same time, many inclusions unnecessary for the body are processed at the lymph stage, in particular we are talking about viruses and infections that are neutralized by lymphocytes and destroyed in the lymph nodes.

It should be noted the special function of lymphatic capillaries, which are larger in size compared to the capillaries of the circulatory system and have thinner walls. Thanks to this, from the interstitial space into the lymph proteins and other components may be supplied.

Additionally, the lymphatic system can be used to cleanse the body, since the intensity of lymph flow largely depends on the compression of blood vessels and muscle tension.

Thus, massage and physical activity can make the movement of lymph more effective. Thanks to this, additional cleansing and healing of the body becomes possible.

Peculiarities

Actually, the word “lymph” comes from the Latin “lympha”, which translates as moisture or clean water. Just from this name it is possible to understand a lot about the structure of lymph, which washes and cleanses the entire body.

Many could observe lymph, since this liquid secreted on the surface when there are wounds on the skin. Unlike blood, the liquid is almost completely transparent.

According to the anatomical structure, lymph belongs to connective tissue and contains a large number of lymphocytes in the complete absence of red blood cells and platelets.

In addition, lymph, as a rule, contains various waste products of the body. In particular, the previously noted large protein molecules that cannot be absorbed into the venous vessels.

Such molecules are often may be viruses Therefore, the lymphatic system is used to absorb such proteins.

Lymph may contain various hormones that are produced by endocrine glands. Fats and some other nutrients come here from the intestines, and protein from the liver.

Direction of lymph movement

The figure below shows a diagram of the movement of lymph in the human lymphatic system. It does not display every lymphatic vessel and the entire lymph nodes, which about five hundred in the human body.

Pay attention to the direction of movement. Lymph moves from the periphery to the center and from bottom to top. The liquid flows from small capillaries, which further connect into larger vessels.

The movement occurs through the lymph nodes, which contain a huge number of lymphocytes and cleanse the lymph.

Typically to the lymph nodes more vessels come in than leave, that is, lymph enters through many channels and leaves through one or two. Thus, the movement continues to the so-called lymphatic trunks, which are the largest lymphatic vessels.

The largest is the thoracic duct, which is located near the aorta and passes through itself lymph from:

all organs that are located below the ribs;
the left side of the chest and the left side of the head;
left hand.

This duct connects to left subclavian vein, which you can see marked in blue in the picture on the left side. This is where lymph flows from the thoracic duct.

It should also be noted right duct, which collects fluid from the right upper side of the body, in particular from the chest and head, arms.

From here the lymph enters right subclavian vein, which is located symmetrically to the left in the figure. Additionally, it should be noted such large vessels that belong to the lymphatic system as:

right and left jugular trunks;
left and right subclavian trunks.

It should be said about the frequent location of lymphatic vessels along blood vessels, in particular venous vessels. If you pay attention to the picture, you will see some similar arrangement of vessels of the circulatory and lymphatic systems.

The lymphatic system has great importance for the human body.

Many doctors consider a lymph analysis to be no less relevant than a blood test, since lymph can indicate some factors that are not detected in other tests.

In general, lymph, in combination with blood and intercellular fluid, constitutes the internal fluid environment in the human body.

The human lymphatic system (LS) is one of the structures that unites disparate organs into a whole. Its smallest branches - capillaries - penetrate most tissues. The biological fluid flowing through the system - lymph - largely determines the vital activity of the body. In ancient times, drugs were considered as one of the main factors determining human temperament. According to many doctors of that time, temperament directly determined both diseases and methods of treating them.

Structure of the lymphatic system

Structural components of the drug:

lymphatic capillaries and vessels;
The lymph nodes;
lymph.

The structure of lymphatic capillaries and vessels

The structure of the drug resembles tree roots, just like the circulatory and nervous systems. Its vessels are located in all organs and tissues, except for the brain and spinal cord and its membranes, internal tissue (parenchyma) of the spleen, inner ear, sclera, lens, cartilage, epithelial tissue and placenta.
Lymph is collected from tissues into blind-ending capillaries. Their diameter is significantly larger than that of the capillaries of the microvasculature. Their walls are thin and highly permeable to liquid and substances dissolved in it, as well as to some cells and microorganisms.
Capillaries drain into lymphatic vessels. These vessels have thin walls equipped with valves. The valves prevent the reverse (retrograde) flow of lymph from the vessels into the tissues. Lymphatic vessels entwine all organs in a wide network. Often such networks in organs are represented by several layers.
Through the vessels, lymph slowly flows into groups of regional lymph nodes. Such groups are located at “busy intersections” of the body: in the armpits, in the elbows, groin, on the mesentery, in the chest cavity, and so on. Large trunks emerging from the lymph nodes flow into the thoracic and right lymphatic ducts. These ducts then open into large veins. Thus, the fluid removed from the tissues enters the bloodstream.

The structure of the lymph node

Lymph nodes are not only the “link” of drugs. They perform important biological functions determined by the peculiarities of their structure.
Lymph nodes consist mainly of lymphoid tissue. It is represented by lymphocytes, plasma cells and reticulocytes. In the lymph nodes, important participants in immune processes—B-lymphocytes—develop and “mature.” Transforming into plasma cells, they mediate humoral immune responses by producing antibodies.
T-lymphocytes are also present deep in the lymph nodes. There they undergo differentiation caused by contact with the antigen. Therefore, lymph nodes participate in the formation of cellular immunity.

Composition of lymph

Lymph refers to human connective tissue. This is a liquid substance containing lymphocytes. It is based on tissue fluid containing water and salts and other substances dissolved in it. Lymph also contains colloidal solutions of proteins, which give it viscosity. This biological fluid is rich in fats. Its composition is close to blood plasma.
The human body contains from 1 to 2 liters of lymph. It flows through the vessels due to the pressure of the newly formed lymphatic fluid and as a result of the contraction of muscle cells in the walls of the lymphatic vessels. An important role in the movement of lymph is played by the contraction of surrounding muscles, as well as the position of the human body and the phases of breathing.

Functions of the lymphatic system

After considering the basic structure of a drug, its various functions become clearer:

drainage;
cleansing;
transport;
immune;
homeostatic.

The drainage function of drugs is to remove excess water, as well as proteins, fats and salts from tissues. These substances are then returned to the bloodstream.
The drug removes many metabolic products and toxins from tissues, as well as many pathogenic microorganisms that have entered the body. Lymph nodes play a barrier role: unique filters for fluid flowing from tissues. Lymph cleanses tissues of cell breakdown products and microbes.
The drug transports immune cells throughout the body. It is involved in the transport of certain enzymes, such as lipases and other important substances. Unfortunately, metastasis of malignant neoplasms is also associated with the performance of drug transport functions.
Lymph nodes are the most important participants in immune processes, ensuring the development of T- and B-lymphocytes. In this regard, mention should be made of small lymph nodes located in the intestinal wall (Peyer's patches) and areas of lymphoid tissue in the tonsils of the pharyngeal ring.
Participating in all of the listed processes, the drug performs its integrating, homeostatic function, ensuring the unchanged internal environment of the body.