From the tissues to the lymph enters. The vital role of the lymphatic system. The structure of the lymphatic system

The fluid that enters the tissue is lymph. The lymphatic system is an integral part of the vascular system, providing the formation of lymph and lymph circulation.

Lymphatic system - a network of capillaries, vessels and nodes through which lymph moves in the body. Lymphatic capillaries are closed at one end, i.e. blindly end in tissues. Lymphatic vessels of medium and large diameter, like veins, have valves. Lymph nodes are located along their course - "filters" that trap viruses, microorganisms and the largest particles in the lymph.

The lymphatic system begins in the tissues of organs in the form of an extensive network of closed lymphatic capillaries that do not have valves, and their walls are highly permeable and have the ability to absorb colloidal solutions and suspensions. Lymphatic capillaries pass into lymphatic vessels equipped with valves. Thanks to these valves, which prevent the reverse flow of lymph, it flows only towards the veins. Lymphatic vessels flow into the lymphatic thoracic duct, through which lymph flows from 3/4 of the body. The thoracic duct drains into the cranial vena cava or jugular vein. Lymph through the lymphatic vessels enters the right lymphatic trunk, which flows into the cranial vena cava.

Rice. Diagram of the lymphatic system

Functions of the lymphatic system

The lymphatic system performs several functions:

• The protective function is provided by the lymphoid tissue of the lymph nodes, which produces phagocytic cells, lymphocytes and antibodies. Before entering the lymph node, the lymphatic vessel divides into small branches that pass into the sinuses of the node. Small branches also depart from the node, which are combined again into one vessel;
• the filtration function is also associated with the lymph nodes, in which various foreign substances and bacteria are mechanically retained;
• the transport function of the lymphatic system is that through this system the main amount of fat that is absorbed in the gastrointestinal tract enters the bloodstream;
• the lymphatic system also performs a homeostatic function, maintaining the constancy of the composition and volume of the interstitial fluid;
• The lymphatic system performs a drainage function and removes excess tissue (interstitial) fluid located in the organs.

The formation and circulation of lymph ensure the removal of excess extracellular fluid, which is created due to the fact that filtration exceeds the reabsorption of fluid into the blood capillaries. Such drainage function The lymphatic system becomes apparent if the outflow of lymph from some area of ​​the body is reduced or stopped (for example, when squeezing the limbs with clothing, blockage of the lymphatic vessels during their injury, crossing during a surgical operation). In these cases, local tissue edema develops distal to the compression site. This type of edema is called lymphatic.

Return to the bloodstream of albumin, filtered into the intercellular fluid from the blood, especially in organs with highly permeable (liver, gastrointestinal tract). More than 100 g of protein returns to the bloodstream per day with lymph. Without this return, the loss of protein in the blood would be irreplaceable.

Lymph is part of the system that provides humoral connections between organs and tissues. With its participation, the transport of signaling molecules, biologically active substances, and some enzymes (histaminase, lipase) is carried out.

In the lymphatic system, the processes of differentiation of lymphocytes transported by the lymph along with immune complexes that perform body's immune defense functions.

Protective function The lymphatic system also manifests itself in the fact that foreign particles, bacteria, remnants of destroyed cells, various toxins, and also tumor cells are filtered out, captured and in some cases neutralized in the lymph nodes. With the help of lymph, red blood cells that have left the blood vessels are removed from the tissues (in case of injuries, damage to blood vessels, bleeding). Often, the accumulation of toxins and infectious agents in the lymph node is accompanied by its inflammation.

Lymph is involved in the transport of chylomicrons, lipoproteins and fat-soluble substances absorbed in the intestine into the venous blood.

Lymph and lymph circulation

Lymph is a blood filtrate formed from tissue fluid. It has an alkaline reaction, it is absent, but contains fibrinogen and, therefore, it is able to coagulate. The chemical composition of lymph is similar to that of blood plasma, tissue fluid and other body fluids.

Lymph flowing from different organs and tissues has a different composition depending on the characteristics of their metabolism and activity. The lymph flowing from the liver contains more proteins, the lymph contains more. Moving along the lymphatic vessels, the lymph passes through the lymph nodes and is enriched with lymphocytes.

Lymph - a clear, colorless liquid contained in the lymphatic vessels and lymph nodes, in which there are no erythrocytes, there are platelets and many lymphocytes. Its functions are aimed at maintaining homeostasis (the return of protein from tissues to the blood, the redistribution of fluid in the body, the formation of milk, participation in digestion, metabolic processes), as well as participation in immunological reactions. The lymph contains protein (about 20 g/l). Lymph production is relatively low (most of all in the liver), about 2 liters are formed per day by reabsorption from the interstitial fluid into the blood of the blood capillaries after filtration.

Lymph formation due to the transition of water and dissolved substances from the blood capillaries to the tissues, and from the tissues to the lymphatic capillaries. At rest, the processes of filtration and absorption in the capillaries are balanced and the lymph is completely absorbed back into the blood. In the case of increased physical activity in the process of metabolism, a number of products are formed that increase the permeability of capillaries for protein, its filtration increases. Filtration in the arterial part of the capillary occurs when the hydrostatic pressure rises above the oncotic pressure by 20 mm Hg. Art. During muscular activity, the volume of lymph increases and its pressure causes the penetration of interstitial fluid into the lumen of the lymphatic vessels. Lymph formation is facilitated by an increase in the osmotic pressure of tissue fluid and lymph in the lymphatic vessels.

The movement of lymph through the lymphatic vessels occurs due to the suction force of the chest, contraction, contraction of the smooth muscles of the wall of the lymphatic vessels and due to the lymphatic valves.

Lymphatic vessels have sympathetic and parasympathetic innervation. Excitation of the sympathetic nerves leads to a contraction of the lymphatic vessels, and when the parasympathetic fibers are activated, the vessels contract and relax, which increases the lymph flow.

Adrenaline, histamine, serotonin increase the flow of lymph. A decrease in the oncotic pressure of plasma proteins and an increase in capillary pressure increase the volume of outflowing lymph.

Formation and amount of lymph

Lymph is a fluid that flows through the lymphatic vessels and is part of the internal environment of the body. The sources of its formation are filtered from the microvasculature into the tissues and the contents of the interstitial space. In the section on microcirculation, it was discussed that the volume of blood plasma filtered into tissues exceeds the volume of fluid reabsorbed from them into the blood. Thus, about 2-3 liters of blood filtrate and fluid of the intercellular medium that are not reabsorbed into the blood vessels per day enter the lymphatic capillaries, the system of lymphatic vessels through the interendothelial clefts, and return to the blood again (Fig. 1).

Lymphatic vessels are present in all organs and tissues of the body with the exception of the superficial layers of the skin and bone tissue. The largest number of them is found in the liver and small intestine, where about 50% of the total daily volume of the body's lymph is formed.

The main constituent of lymph is water. The mineral composition of the lymph is identical to the composition of the intercellular environment of the tissue in which the lymph was formed. Lymph contains organic substances, mainly proteins, glucose, amino acids, free fatty acids. The composition of the lymph flowing from different organs is not the same. In organs with a relatively high permeability of blood capillaries, such as the liver, lymph contains up to 60 g/l of protein. The lymph contains proteins involved in the formation of blood clots (prothrombin, fibrinogen), so it can clot. The lymph flowing from the intestines contains not only a lot of protein (30-40 g/l), but also a large amount of chylomicrons and lipoproteins formed from aponrotheins and fats absorbed from the intestines. These particles are in suspension in the lymph, transported by it into the blood and give the lymph a similarity to milk. In the composition of the lymph of other tissues, the protein content is 3-4 times less than in the blood plasma. The main protein component of tissue lymph is the low molecular weight fraction of albumin, which is filtered through the wall of capillaries into extravascular spaces. The entry of proteins and other large molecular particles into the lymph of the lymphatic capillaries is carried out due to their pinocytosis.

Rice. 1. Schematic structure of a lymphatic capillary. The arrows show the direction of lymphatic flow.

Lymph contains lymphocytes and other forms of white blood cells. Their number in different lymphatic vessels varies and is in the range of 2-25 * 10 9 / l, and in the thoracic duct is 8 * 10 9 / l. Other types of leukocytes (granulocytes, monocytes and macrophages) are contained in the lymph in a small amount, but their number increases with inflammatory and other pathological processes. Red blood cells and platelets can appear in the lymph when blood vessels are damaged and tissue injuries.

Absorption and movement of lymph

Lymph is absorbed into the lymphatic capillaries, which have a number of unique properties. Unlike blood capillaries, lymphatic capillaries are closed, blindly ending vessels (Fig. 1). Their wall consists of a single layer of endothelial cells, the membrane of which is fixed with the help of collagen filaments to extravascular tissue structures. Between endothelial cells there are intercellular slit-like spaces, the dimensions of which can vary widely: from a closed state to a size through which blood cells, fragments of destroyed cells and particles comparable in size to blood cells can penetrate into the capillary.

The lymphatic capillaries themselves can also change their size and reach a diameter of up to 75 microns. These morphological features of the structure of the walls of the lymphatic capillaries give them the ability to change the permeability over a wide range. Thus, during contraction of skeletal muscles or smooth muscles of internal organs, due to the tension of collagen filaments, interendothelial gaps can open, through which the intercellular fluid, the mineral and organic substances contained in it, including proteins and tissue leukocytes, freely move into the lymphatic capillary. The latter can easily migrate into the lymphatic capillaries also due to their ability to amoeboid movement. In addition, lymphocytes, which are formed in the lymph nodes, enter the lymph. The flow of lymph into the lymphatic capillaries is carried out not only passively, but also under the influence of negative pressure forces that arise in the capillaries due to the pulsating contraction of the more proximal parts of the lymphatic vessels and the presence of valves in them.

The wall of the lymphatic vessels is built of endothelial cells, which, on the outside of the vessel, are covered in the form of a cuff by smooth muscle cells located radially around the vessel. Inside the lymphatic vessels there are valves, the structure and principle of functioning of which are similar to the valves of the venous vessels. When smooth myocytes are relaxed and the lymphatic vessel is dilated, the valve leaflets open. With the contraction of smooth myocytes, which causes narrowing of the vessel, the pressure of the lymph in this area of ​​the vessel increases, the valve flaps close, the lymph cannot move in the opposite (distal) direction and is pushed through the vessel proximally.

Lymph from the lymphatic capillaries moves into postcapillary and then into large intraorgan lymphatic vessels that flow into the lymph nodes. From the lymph nodes, through small extraorganic lymphatic vessels, lymph flows into larger extraorganic vessels that form the largest lymphatic trunks: the right and left thoracic ducts, through which lymph is delivered to the circulatory system. From the left thoracic duct, lymph enters the left subclavian vein near its junction with the jugular veins. Most of the lymph moves into the blood through this duct. The right lymphatic duct delivers lymph to the right subclavian vein from the right side of the chest, neck, and right arm.

Lymph flow can be characterized by volumetric and linear velocities. The volumetric flow rate of lymph from the thoracic ducts to the veins is 1-2 ml / min, i.e. only 2-3 l / day. The linear speed of lymph movement is very low - less than 1 mm/min.

The driving force of the lymph flow is formed by a number of factors.

• The difference between the hydrostatic pressure of the lymph (2-5 mm Hg) in the lymphatic capillaries and its pressure (about 0 mm Hg) at the mouth of the common lymphatic duct.
• Contraction of smooth muscle cells in the walls of lymphatic vessels that move lymph towards the thoracic duct. This mechanism is sometimes called the lymphatic pump.
• Periodic increase in external pressure on the lymphatic vessels, created by contraction of the skeletal or smooth muscles of the internal organs. For example, the contraction of the respiratory muscles creates rhythmic pressure changes in the chest and abdominal cavities. The decrease in pressure in the chest cavity during inhalation creates a suction force that promotes the movement of lymph into the thoracic duct.

The amount of lymph formed per day in a state of physiological rest is about 2-5% of body weight. The rate of its formation, movement and composition depend on the functional state of the organ and a number of other factors. Thus, the volumetric flow of lymph from the muscles during muscular work increases by 10-15 times. After 5-6 hours after eating, the volume of lymph flowing from the intestine increases, its composition changes. This occurs mainly due to the entry of chylomicrons and lipoproteins into the lymph.

Clamping the veins of the legs or standing for a long time leads to difficulty in returning venous blood from the legs to the heart. At the same time, the hydrostatic pressure of blood in the capillaries of the extremities increases, filtration increases and an excess of tissue fluid is created. The lymphatic system under such conditions cannot provide sufficient drainage function, which is accompanied by the development of edema.

Lymphatic system (LS) is a set of thin lymphatic vessels passing through the entire body.

The LS is similar to the circulatory system - there are blood vessels in all parts of the body, as well as blood-carrying veins and arteries. However, the vessels of the LS are much thinner and a colorless liquid, the lymph, is transmitted through them.

Lymph It is a clear liquid containing a large number of lymphocytes (white blood cells). Plasma seeps out of the capillaries, surrounds and washes the tissues of the body, and then flows into the lymphatic vessels.

After that, the fluid, which by that time becomes lymph, passes through the lymphatic system into the largest lymphatic vessel - the thoracic duct, after which it returns back to the circulatory system.

The lymph nodes

Along the lymph vessels are small bean-shaped lymph glands, also called lymph nodes. Some of them are easy to determine by palpation.

Lymph nodes of this kind are present in many parts of your body, including:

• In the armpit;
• In the groin;
• In the neck.

There are also lymph nodes that cannot be determined by palpation. They are located:

• In the abdominal cavity;
• In the pelvic area;
• In the chest.

Other organs of drugs

In addition to the lymphatic vessels and lymph nodes, the LS includes the following organs:

• the spleen;
• thymus gland;
• tonsils;
• Adenoids.

The spleen is located in the left hypochondrium. It consists of two different types of tissue: red pulp and white pulp. The red pulp filters worn out and damaged red blood cells and then recycles them. The white pulp contains a large amount lymphocytes And T-lymphocytes. These are white blood cells that play an important role in fighting various infections. When blood passes through the spleen, lymphocytes react to any sign of infectious diseases, starting to actively resist them.

(or thymus) is a small gland located under the sternum. It is involved in the reproduction of white blood cells. As a rule, the thymus is most active during adolescence, in the process of growing up, activity decreases.

tonsils are two glands located at the back of the larynx. tonsils And adenoids(the so-called “nasopharynxes” of the tonsils) help protect the entrance to the digestive system and lungs from viruses and bacteria.

Adenoids are located on the vault of the nasopharynx, somewhat closer, most often, to its back wall.

LAN functions

The human lymphatic system performs several functions.:

• Ensuring the flow of fluid from the tissues back into the blood;
• Lymph filtration;
• Blood filtration;
• Fight against infectious diseases.

Drainage of fluid into the blood

In the process of blood circulation, plasma leaks from the blood vessels into the tissues of the body. This fluid is very important, it has a dual function: it provides food for the cells and removes waste back into the bloodstream. The spent plasma drains into the lymph vessels and passes through them to the base of the neck, where it is cleaned and returned to the bloodstream. This circulation of fluid through the body occurs continuously.

Lymph filtration

As fluid passes through the lymph nodes, it is cleared. White blood cells attack any viruses or bacteria they find. If the patient is susceptible to oncological diseases and the tumor begins to metastasize, the separated cancer cells are often filtered out by the nearest lymph nodes. That is why doctors first check the lymph nodes for the presence of metastases in them, this allows you to determine how far the cancer has spread.

Blood filtration

This function is performed by the spleen. As the blood passes through this organ, any worn out or damaged red blood cells are removed from the blood, which are subsequently destroyed by the spleen. They are replaced by new red blood cells produced by the bone marrow. In addition, the spleen filters out bacteria, viruses and other foreign particles contained in the blood - the white pulp containing white blood cells is responsible for this.

Fight against infectious diseases

This function of the drug is, in fact, an important part of the immune response. One of the primary signs of an infectious disease is enlarged lymph nodes. Drugs fight infection in the following ways:

• Participates in the creation of white blood cells (lymphocytes) that produce antibodies;
• The lymph nodes contain special blood cells - macrophages. They absorb and destroy any foreign particles, such as bacteria.

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The lymphatic system, which in Latin is called systema lymphatica, in the human body performs important functions and is responsible for maintaining immunity. This most important part of the human vascular system has a clear structure. The main function of the systema lymphatica is to cleanse the cells and tissues of the body. Each lymph node performs the functions of a biological filter.

What is the lymphatic system

The entire human body is covered by a system of lymph nodes and blood vessels, which ensures the functioning of the immune system. The lymphatic system carries away tissue fluid from the intercellular space. Such a structure is no less important part of the vascular circulation than the venous and arterial systems. The work of the systema lymphatica is clearly not visible.

It is very rare for lymph to leak through the skin, but people always notice the results of the lymphatic system. However, few understand the essence of such a process. This is a complex non-closed structure. It does not have a central pump, so it is different from the circulatory system. The lymphatic system is a whole complex of small and large lymphatic vessels - trunks and ducts, which permeate the entire human body.

Through them, lymph flows from areas of the body to the terminal sections of the veins. About 460 grouped or single lymph nodes in different parts of the body along the lymphatic vessels are present in the human body. Groups of lymph nodes work constantly. They are located next to the veins and arteries. This number of lymph nodes is enough for the human body to feel healthy. These vessels are interconnected by lymph nodes.

Small and large vessels are grouped. These are groups with different lymph nodes. They go to the lymph nodes (lat. nodi lymphatici), ranging in size from a large bean seed to a millet grain. There are 150 regional groups of lymph nodes connected by vessels. Each node is responsible for a specific part of the body. The weight of all lymph nodes is 1% of body weight, up to 1 kg. The lymphocytes needed to fight infection are produced in the lymph nodes.

The lymphatic capillaries form the basis of this system. They are everywhere. These thin capillaries collect fluid in the body that is there. Such a biological fluid contains various useful and harmful toxic substances. These toxins (lat. Toxicum) poison our body, so the lymphatic system collects these substances in the body.

Lymph is a fluid tissue of the body.

Lymph, which is constantly filtered in the lymph nodes, contains a lot of leukocytes. These are active white blood cells: macrophages, B-lymphocytes, T-cells (lat. Thymus). Such leukocytes tend to absorb various microbes. They must find infectious agents, destroy their toxins.

Platelets and erythrocytes are absent in the lymph. It is constantly formed by filtration of blood plasma. Such a colorless liquid always circulates in this system. In the body of an adult, up to 2 liters of this transparent biological fluid circulate. Lympha moves slowly under slight pressure. Lymph always flows from bottom to top. This biological fluid slowly carries tissue fluid from the fingers of the lower extremities to the thoracic lymphatic duct. Only in this direction can the lympha collect everything superfluous in the body and bring it out.

Lymphatic capillaries have special valves that prevent backflow of lymph. Lympha is engaged in the purification of blood in the human body. However, sometimes these valves in humans are destroyed, and the flow of lymph slows down. With an infectious process, the elbow lymph nodes become inflamed on the hand. In these situations, swelling of the limbs occurs.

This indicates damage to the lymphatic vessels. How does lymph move? Microcirculation processes determine the volume and rate of lymph formation. When there is obesity, or a person is sitting for a long time, the movement of the lymph is minimal, since there is practically no active physical movement. If a person moves vigorously, the muscles actively contract. Lymph is pumped to the next lymphangion.

Significance of the lymphatic system

The structure of the lymphatic system

What is the location of the lymph nodes? The structures of the systema lymphatica are not able to remove toxins and poisons through the skin. In our body there are such organs with a mucous membrane. A group of lymph nodes releases these toxins to a specific area in order to remove poisons through the mucous membranes. Since the systema lymphatica works from the bottom up, the first area of ​​lymphatic evacuation is the mucous membranes of men and women.

Functioning

Lymph nodes in the abdominal cavity

Patients complain about the appearance of some pathological discharge. Lymphocytes cleanse the vagina, urethra, male genitalia. The femoral triangle consists of. The destruction of microbes is accompanied by inflammation. Deep lymph nodes are compressed, the thigh hurts. When toxins are released, the body will be clean.

The second area of ​​evacuation of poisons is the intestines. There are many lymph nodes in the abdomen. If the body is poisoned by malnutrition, the lymph nodes remove toxins through the lymph nodes located in the intestines. A group of para-aortic lymph nodes is located in the chest and abdominal cavity. If you start drinking fixing drugs with diarrhea, these toxins will remain in the affected body.

sweat glands

The sweat glands are another evacuation zone for toxins. Especially a lot of them in the armpits. The person must sweat. However, many people actively use antiperspirants to combat excessive sweating, which close the sweat glands. All poisons remain in this zone. In severe cases, you have to contact the surgeon. If the lymph nodes on the collarbone are enlarged, this may be a sign of a tumor.

Nasopharynx, oral cavity

The nose, the nasal cavity, is an important area for the evacuation of toxicum. Through the nose, pathogens that have entered by airborne droplets are removed. If a person is self-treated, vasoconstrictor drops are often used. Instead of removing the pathological contents, the patient leaves microbes in the body. A sign of damage to the system are the symptoms of sinusitis.

In the nasopharynx there is a special lymphoid tissue that captures microbes. Staphylococcal infection always exits through the nasal cavity. If it is not possible to quickly cope with an airborne infection, the adenoids increase. The lymph nodes in the nose swell. If these essential organs are removed, the body's ability to fight infection is reduced.

The collection of lymph in the area of ​​the mouth, teeth, tongue is carried out by the chin lymph nodes. Lymphadenitis is an inflammation of the lymph nodes of the face. The salivary glands are part of the systema lymphatica. Together with the oral fluid, toxins and poisons are carried into the digestive tract for removal from the body. With the defeat of the jaw lymph nodes, the lower jaw is very sore. It is important to make swallowing movements. This stimulates the production of saliva.

inflammation of the palatine tonsils

The palatine tonsils stand guard, protecting the body. This is the place through which the body can remove all the bad. Streptococcus is always excreted through the tonsils. The body is fighting, so there are tonsillitis, rheumatism. But if a person violates the laws of a healthy life, the palatine tonsils are constantly inflamed.

With the defeat of the lymph nodes on the face, the chin hurts. Tonsillitis develops, the palatine tonsils do not cope with their work. Inflamed submandibular lymph nodes get an infection from the facial lymph node. In the case of tonsillectomy, without extreme necessity, another barrier disappears that protected human health.

The larynx is the next barrier to infection. If the lymphatic system has found microbes and removes them through the larynx, laryngitis develops. In the ear area, the lymph nodes of the face often become inflamed. The next springboard for the evacuation of poisons and microbes is the trachea. There are lymph nodes on both sides of the trachea. Lymphocytes come out of the lymph nodes. When the body tries to remove toxins in this way, tracheitis develops. Virchow's supraclavicular lymph node receives lymph from the abdominal cavity through the thoracic duct.

Bronchi and lungs

The next excretory path of the systema lymphatica is the bronchi. It is an important component of the immune system. The passage of infection further block the lymph nodes with the help of tracheal lymph. The fungus is secreted through the nearest organs. Fungal bronchitis begins if the entire body is affected by the pathogen. If you take cough pills with bronchitis, mucus does not come out of the bronchi. The disease is delayed, the patient's condition worsens. As a result of settling of mycobacteria, inflammation of the intrathoracic lymph nodes often develops.

The lungs are the most important area for the evacuation of various debris from the body. The lymphatic capillaries in the lungs often bear the brunt of the infection. They are called bronchopulmonary lymph nodes. Through the deep and superficial plexuses of the lungs, the respiratory organ is cleansed. A dangerous bacterium enters the zone of the lymph nodes. This is where it gets destroyed. In tuberculosis, the intrathoracic lymph nodes are involved in the pathological process.

The cervical group of lymph nodes neutralizes microbes entering the body through the upper respiratory tract and mouth. An increase in the lymph nodes of the neck may indicate the hard work of the systema lymphatica. Non-working lymph nodes in the face often cause severe muscle blocks, as lymph flow is hindered. The sublingual lymph node sensitively reacts to any changes in the body.

Lymphatic system. Video

Complications of the lymph

If the lymphatic system is overloaded, and a new infection enters the body, problems arise. Systema lymphatica puts debris into the skin because the system is clogged with other toxins. Breast cancer can provoke metastases to the subclavian lymph nodes. Through the skin, the body tries to expel the fungus. However, the dense epidermis does not let harmful substances out. There are eczema, psoriasis, neurodermatitis. These are not diseases, but a painful condition, a manifestation of problems with an overloaded lymphatic system. It is necessary to cleanse the body.

cleansing the body

Bad ecology, wrong way of life, low-quality food harm the health of every person. After the age of 30, the body fluids of many people are heavily contaminated. In fat cells, tissues, there can be many kinds of toxins, microorganisms, harmful substances that weaken the immune system.

In conclusion

One of the most important and complex systems in the human body is the systema lymphatica. The lymphatic system works independently of our thinking. Lymph movement is provided by various muscles. Lympha is able to fully function only under the condition of physical activity of a person. After a long sitting position, it is important to actively move. At the same time, normal lymphatic flow is started. As a result, lymph performs its functions in the system. Its task is to catch harmful substances in the body with the help of leukocytes and neutralize them.

Leukocytes find microbes and eat them, dying in the process. Lymph saves the patient at the cost of his own life. A sick person should not interfere with this process, but competently help his body. This can only be done under the guidance of a qualified medical professional.

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 call lymph.

However, lymph has great importance 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 work of other systems, but not many people know about the high importance of the lymphatic system. If the lymph does not circulate through the body for only 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 isolate the following differences:

1. openness, unlike the circulatory system, the lymphatic system is open, that is, there is no circulation as such.
2. Unidirectional 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 fluid first collects in the smallest capillaries and then moves into larger vessels, and the movement goes only in this direction.
3. There is no central pump. In order to ensure the movement of fluid in the right direction, only a system of valves is used.
4. More slow motion fluid compared to the circulatory system.
5. The presence of special anatomical elements- lymph nodes that perform a significant function and are a kind of warehouse for lymphocytes.

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

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

You yourself can notice this activity when you have, which 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, then it should be noted the connection of the lymphatic system with the cardiovascular system. It is thanks to the lymph that delivery of various items, which cannot be immediately in the cardiovascular system:

• proteins;
• fluid from the tissue and interstitial space;
• fats, which come primarily from the small intestine.

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

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

It should be noted the special function of the lymphatic capillaries, which are larger in comparison with the capillaries of the circulatory system and have thinner walls. Due to this, from the interstitial space to the lymph proteins and other components can be supplied.

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

Thus, massage and physical activity can make the movement of lymph more efficient. 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. Only from this name it is possible to understand a lot about the structure of the lymph, which washes and cleanses the entire body.

Many could observe lymph, since this liquid exudes on the surface of 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 erythrocytes 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.

The lymph may contain various hormones that are produced by the endocrine glands. From the intestines, fats and some other nutrients come here, from the liver - protein.

Direction of lymph flow

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

Pay attention to the direction of travel. Lymph moves from the periphery to the center and from the bottom up. Fluid flows from small capillaries, which then join into larger vessels.

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

Usually to the lymph nodes more vessels come in than leave, that is, lymph enters through many channels, and leaves 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 lymph through itself from:

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

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

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

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

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

The lymphatic system has great importance for the human body.

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

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

Lymphatic system - an integral part of the vascular system that drains tissues by forming lymph and conducting 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 a fluid that fills the vessels of the lymphatic channel 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 the 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 the lymph is 8-10 times less than in the blood. 80% of the formed elements of the lymph are lymphocytes, and the remaining 20% ​​are the share of other white blood cells. There are no normal erythrocytes in the lymph.

Functions of the lymphatic system:

Tissue drainage.

Ensuring continuous fluid circulation 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 away 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 that ensure the movement of lymph

Filtration pressure (due to the filtration of fluid from the blood capillaries into the intercellular space).

Permanent formation of lymph.

Availability of valves.

Contraction of the surrounding skeletal muscles and muscle elements of the internal organs (they squeeze the lymphatic vessels and the lymph moves in the direction determined by the valves).

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

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

Lymph capillaries- thin-walled vessels, the diameter of which (10-200 microns) exceeds the diameter of blood capillaries (8-10 microns). The lymphatic capillaries are characterized by tortuosity, the presence of constrictions 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 (there is a basement membrane in the blood capillaries outside the endothelium).

Lymph 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 the lymphatic capillaries and blood 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 in only one direction.

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

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

1 - segment of the lymphatic vessel with valves.

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

There are also intraorganic and extraorganic lymphatic vessels. Due to the existence of numerous anastomoses, intraorganic lymphatic vessels form wide-looped plexuses. The lymphatic vessels emerging from these plexuses accompany the arteries, veins and exit the organ. Extraorganic lymphatic vessels are sent to nearby groups of regional lymph nodes, usually accompanying blood vessels, more often veins.

On the path of the lymphatic vessels are located The lymph nodes. This determines that foreign particles, tumor cells, etc. linger 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 organ or tissue - these are the lymph nodes that are the first in the path of the lymphatic vessels that carry lymph from this area of ​​​​the body.

lymph 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 lymph trunks in the human body.

jugular trunk(right and left) is represented by one or more 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 upper 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 divert lymph from the lower limb, walls and organs of the pelvis and abdomen.

Inconsistent intestinal lymphatic trunk occurs in about 25% of cases. It is formed from the efferent lymphatic vessels of the mesenteric lymph nodes and flows into the initial (abdominal) part of the thoracic duct with 1-3 vessels.

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 - unpaired vein; 9 - semi-unpaired 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

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 so-called venous angle formed by the union 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 limb. The right lymphatic duct flows into the right venous angle, through which lymph is brought from 1/4 of the body: from the right half of the chest, neck, head, 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 -1 lumbar vertebrae by the fusion of the right and left lumbar trunks (trunci lumbales dexter et sinister). Sometimes at the beginning of 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 to push the lymph into the thoracic duct. At the level of the VII cervical vertebra, the thoracic duct forms an arc and, having rounded 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 the penetration of blood from the vein into the duct. 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, formed at the confluence of the right subclavian trunk (truncus subclavius ​​dexter), which carries lymph from the right upper limb, the right jugular trunk (truncus jugularis dexter), which collects lymph from the right half of the head and neck, and the right bronchomediastinal trunk (truncus bronchomediastinalis dexter), which brings lymph from the right half of the chest. However, more often the right lymphatic duct is absent, and the trunks forming it flow into the right venous angle on their own.

Lymph nodes of certain areas of the body.

Head and neck

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

So, 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. In the parotid lymph nodes, located on the surface and in the thickness of the gland of the same name, lymph flows from the forehead, temple, upper eyelid, auricle, walls of the external auditory canal.

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

1 - anterior ear lymph nodes; 2 - rear ear lymph nodes; 3 - occipital lymph nodes; 4 - lower ear lymph nodes; 5 - buccal lymph nodes; 6 - chin 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 in large numbers accompany the internal jugular vein, and superficial lie near the external jugular vein. In these nodes, mainly in the deep cervical ones, 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 on the upper limb: elbow and axillary. The ulnar nodes lie in the ulnar fossa and receive lymph from part of the vessels of the hand and forearm. Through the efferent vessels of these nodes, the lymph flows into the axillary nodes. 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 depth 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.

chest 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 bifurcation of the trachea (tracheobronchial), in the hilum 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 (peripheral), etc. Lymph flows from the organs and partially from the walls of the chest cavity into these nodes.

lower limb

On the lower extremity, 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 arteries and veins. These nodes receive lymph from part of the lymphatic vessels of the foot and lower leg. The efferent vessels of the popliteal nodes carry lymph mainly to the inguinal nodes.

Inguinal lymph nodes are divided into superficial and deep. Superficial inguinal nodes lie below the inguinal ligament under the skin of the thigh on top of the fascia, and 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 to the external iliac nodes, which are related to the nodes of the pelvis.

In the pelvis, the lymph nodes are located, as a rule, along the course of the blood vessels and have a similar name (Fig. 61). So, 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 to 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 course of the blood vessels, including the vessels passing through the gates of the organs. So, along the course of the abdominal aorta and the 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 lies 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 region of the gate 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. Lymph from the lower extremities and pelvis also enters the lumbar lymph nodes. It should be noted that the lymphatic vessels of the small intestine are called lactiferous, 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).