Lymphatic system: general structure and characteristics. Human Anatomy and Physiology: Study Guide The Lymphatic System Begins
The human lymphatic system (HLS) is a component of the vascular system, which is important in cleansing the tissues and cells of the body. Lymph nodes are links in the LChS, each of which is responsible for filtering a clear liquid (lymph) from harmful substances.
It is impossible to say unequivocally why the lymphatic system is needed, since it has numerous functions, which will be discussed below.
The structure of the LSC includes:
- lymph;
- lymphatic vessels and capillaries;
- lymph nodes (immune links, formations).
The circulatory and lymphatic systems differ significantly from each other. There are no erythrocytes in a clear liquid, and there are much fewer protein molecules than in blood. LSP is not closed. It lacks the main pump, i.e. the heart. Lymph moves into the LSP smoothly and under minimal pressure.
The structure of the human lymphatic system will tell the scheme. It will also indicate the features of the movement of the lymph. The components of the most important part of the body are described in detail below.
Lymph
The word "lymph" in Latin means "clear water". This is not surprising, because this liquid cleanses the body of harmful substances. In its structure, lymph is a connective tissue and has many lymphocytes, practically does not contain platelets and erythrocytes.
The composition of "pure water" includes the products of the vital activity of the body, including large molecules of proteins. Most often they are viruses that are filtered by the lymphatic system. The clear liquid contains various hormones produced by the endocrine glands.
Lymph moves from the periphery to the center, moving from bottom to top. It passes from small capillaries, which gradually flow into large vessels. The movement goes through formations - lymph nodes that perform the function of filtering. In total, the lymphatic system contains about 500 such anatomical structures.
Lymphatic vessels and capillaries
Click to enlarge
LSP outwardly resembles the roots of a tree. This brings it closer to the nervous and circulatory systems. Lymphatic vessels permeate almost the entire human body, excluding the sclera, the inner part of the ear, and some other segments.
From the tissues, lymph enters the capillaries, which are connected to the lymphatic vessels. The latter surround all organs and often lie in several layers.
The lymph passes through the vessels to the regional links of immunity, localized in the inguinal and elbow areas, armpits, chest, etc. Large trunks emerge from the nodes, which flow into the ducts that open the way to the circulatory system for “clean water”.
Lymph nodes (immune links)
A lymph node (LN) is often a rounded formation that has a gray-pink color and sizes from 0.5 to 50 mm or more. Immune links are localized along the lymphatic and near the blood vessels. Each of the formations serves as a kind of filter. They are responsible for cleansing the body not only from microbes, but also from cancer cells. Thus, it is an essential part of human health.
The node structure includes:
- connective tissue capsule;
- stroma (structural basis) in which macrophages are located;
- cortical substance, consisting of a superficial part and a deep cortex.
The immune links are based on lymphoid tissue, in which there are lymphocytes, reticulocytes and plasma cells. In the formations, the most important components of immunity develop - B-lymphocytes, which participate in its formation.
Functions of the lymphatic system
Lymphocytes actively fight bacteria and viruses that enter the body from outside. This ensures the normal functioning of the body's defenses. Immune links increase if the number of microbes is too large and they can not cope with them. In this case, the help of a specialist is required.
The lymphatic system performs the function of cleansing from microbes and is responsible for the delivery of the most important elements to the venous bed. Later, these components through the blood circulation enter the cardiovascular system and leave the human body.
Most harmful substances are eliminated even at the stage of filtration with a clear liquid, i.e., they are destroyed in the links of immunity. The body normally “works” thanks to the lymphatic capillaries, through which proteins and other compounds come from the interstitial space into the clear liquid.
The way "clear water" flows is determined by the degree of muscle tension. Physical activity has a beneficial effect on the movement of lymph, promotes high-quality cleansing of the body and normalization of human health.
Major diseases
The most common problems with the lymphatic system are:
- Lymphoma:
- Hodgkin - LSP cancer with a high degree of malignancy;
- non-Hodgkin's (B-cell or T-cell).
- Lymphadenitis - inflammation of the immune links:
- acute, provoked by viruses or bacteria;
- chronic, caused by syphilis, immunodeficiency or tuberculosis, less often - influenza;
- purulent (occurs in advanced cases, characterized by the formation of exudate in the node).
- Lymphedema (including elephantiasis) is a persistent swelling of an extremity that develops as a result of damage to the LSP, which contributes to impaired lymph circulation or the formation of lymphostasis.
Signs of malfunction of the lymphatic system are:
- swelling of the fingers;
- pain in the chest;
- cold extremities;
- cellulite;
- dry skin.
The lymphatic system and lymph are the most important components of the body, for the normal functioning of which are useful:
- physical activity;
- trampolining;
- yoga classes;
- proper diet;
- breathing exercises;
- rejection of bad habits;
- food according to Ayurveda.
If the cleansing function is violated, health problems arise. A person needs continuous work of LSP. How the structures cope with their task depends on his well-being. To maintain health, lymph is needed periodically.
Which doctor should I contact?
Treatment of LSP pathologies is reduced to the use of drugs or surgery. Having found deviations from the norm, you need to consult with a pediatrician / therapist who will refer you to a specialist.
Below is a table explaining which doctors deal with LSD diseases.
| leading symptom | Narrow specialist |
| Enlarged lymph nodes in the neck | Otorhinolaryngologist |
| Soreness and proliferation of lymphoid tissue under the jaw | Dentist |
| Increase in immune links in the groin area | Gynecologist or urologist |
| Change in the size of formations, accompanied by hemoptysis, a sharp decrease in weight, increased sweating, fever |
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.
II. The main structural elements of the lymphatic system
III. Drainage pathways for lymph from various parts of the body
I. General characteristics and functions of the lymphatic system
lymphatic system is part of the vascular system, complementing the venous bed.
Functions of the lymphatic system
1. Drainage (transport) function- 80-90% of the tissue filtrate is absorbed into the venous bed, and 10-20% - into the lymphatic.
2. Resorption function- together with the lymph, colloidal solutions of proteins, lipids, foreign agents (bacteria, viruses, foreign bodies) are removed from the tissues.
3. Lymphopoietic function- Lymphocytes are formed in the lymph nodes.
4. Immunological function- provides humoral immunity by forming antibodies.
5. barrier function- neutralizes foreign agents (bacteria, viruses, malignant cells, foreign bodies).
Lymph- a transparent yellowish liquid, contains blood cells - lymphocytes, as well as a small amount of eosinophils and monocytes. In its composition, lymphoplasm resembles blood plasma, but differs in a lower protein content and a lower colloid osmotic pressure. The volume of lymph in the body is from 1 to 2 liters. Lymph formation occurs at the level of the microcirculation, where the lymphatic capillaries are in close contact with the blood capillaries.
Features of the structure of the lymphatic system:
The lymphatic system is not functionally closed - lymphatic capillaries begin blindly.
The presence of valves in the lymphatic vessels that prevent the reverse flow of lymph.
Lymphatic pathways are discontinuous (interrupted by lymph nodes).
II. The main structural elements of the lymphatic system.
Lymph capillaries
Lymphatic vessels
The lymph nodes
lymph trunks
lymphatic ducts
1. Lymph capillaries- are the initial link, the "roots" of the lymphatic system. They are characterized by:
Ø begin blindly, so that the lymph can move in one direction - from the periphery to the center;
Ø have a wall consisting only of endothelial cells, there is no basement membrane and pericytes;
Ø larger diameter (50-200 microns) compared to hemocapillaries (5-7 microns);
Ø the presence of filaments - bundles of fibers that connect capillaries with collagen fibers. With edema, for example, the tension of the fibers helps to increase the lumen;
Ø in organs and tissues, capillaries form networks (for example, in the pleura and peritoneum, the networks are single-layer, in the lungs and liver - three-dimensional);
Ø are present in all organs and tissues of the human body, except for the brain and spinal cord and their membranes; eyeball; inner ear; epithelial cover of the skin and auditory membranes; cartilage; spleen; bone marrow; placenta; enamel and dentin.
Lymphatic capillaries are involved in the formation of lymph, during which the main function of the lymphatic system is carried out - drainage reabsorption of metabolic products and foreign agents.
2. Lymphatic vessels formed by the fusion of lymphatic capillaries. They are characterized by:
Ø in addition to the endothelium, there is a layer of smooth muscle cells and connective tissue in the vascular wall;
Ø there are valves that determine the direction of lymph flow through the lymphatic vessels;
Ø lymphagion- structural and functional unit of the lymphatic system, the area of the lymphatic vessel between the valves, intervalve systems;
Ø have lymph nodes along the way
By topography
o intraorganic, form a plexus;
o extraorganic.
In relation to the superficial fascia, lymphatic vessels (external) can be:
o surface(located outward from the superficial fascia, next to the saphenous veins);
o deep(located under their own fascia, accompanying deep vessels and nerves).
In relation to the lymph node lymphatic vessels can be:
o bringing(the lymph flows through them to the lymph node);
o enduring(lymph flows from a lymph node).
3. Lymph nodes located along the path of the lymphatic vessels. The nodes belong to both the lymphatic and immune systems.
Functions of the lymph nodes:
Ø lymphopoietic- produce lymphocytes
Ø immunopoietic- production of antibodies, activation of B-lymphocytes
Ø barrier-filtration– detain foreign agents (bacteria, viruses, tumor cells, foreign bodies). Those. lymph nodes are mechanical and biological filters of lymph
Ø propulsive function- carries out the promotion of lymph, since there are elastic and muscle fibers in the capsule of the lymph nodes.
In the lymph nodes, tumor cells can multiply, which leads to the formation of a secondary tumor (metastasis). According to Mascagni's rule, a lymphatic vessel passes through at least one lymph node. There can be up to 10 nodes on the way of the lymph. The exceptions are the liver, esophagus and thyroid gland, lymphatic vessels, which, bypassing the lymph nodes, flow into the thoracic duct. Therefore, tumor cells from the liver and esophagus quickly enter the bloodstream, increasing metastases.
The external structure of the lymph nodes:
Ø Nodes are usually located in groups from units to several hundred
Ø knots are pink-gray in color, rounded, bean-shaped or ribbon-shaped
Ø sizes vary from 0.5 to 50 mm (an increase indicates the penetration of foreign agents into the body, causing a response of nodes in the form of increased reproduction of lymphocytes)
Ø The afferent lymphatic vessels approach the convex side of the node. The efferent vessels come out of the loop depression - the gate of the node.
The internal structure of the lymph nodes:
Ø connective tissue capsule covers the outside of the lymph node
Ø capsular trabeculae extend from the capsule into the node, perform a supporting function
Ø reticular tissue (stroma) fills the space between trabeculae, contains reticular cells and fibers
Ø The parenchyma of the lymph node is subdivided into cortex and medulla
Ø cortical substance is closer to the capsule. Lymph nodules are located in the cortical substance, proliferation and differentiation of B-lymphocytes occur in them.
Ø The medulla occupies the central part of the lymph node, represented by strands of lymphoid tissue, where B-lymphocytes mature and turn into plasma cells
Ø The medulla together with the lymphatic nodules of the cortex form a B-dependent zone
Ø on the border of the lymphatic nodules with the medulla, there is a paracortical zone (thymus-dependent, T-zone), where the maturation and differentiation of T-lymphocytes occurs
Ø The cortex and medulla are permeated with a network of lymphatic sinuses, through which lymphocytes and macrophages can penetrate in both directions.
Afferent vessel subcapsular sinus cortical sinus medulla sinus portal sinus efferent vessels
4. Lymph trunks- large lymphatic vessels (collectors) that collect lymph from several areas of the body and organs. They are formed at the confluence of the efferent vessels of the lymph nodes and exit into the thoracic duct or the right lymphatic duct.
Lymph trunks:
Ø jugular trunk(paired) - from head to neck
Ø subclavian trunk(paired) - from the upper limbs
Ø bronchomediastinal trunk(paired) - from the chest cavity
Ø lumbar trunk(paired) - from the lower extremities, pelvis and abdominal cavity
Ø intestinal(unpaired, unstable, occurs in 25% of cases) - from the small and large intestines.
5. Lymphatic ducts- the thoracic duct and the right lymphatic duct are the largest collector lymphatic vessels, through which the lymph flows from the lymphatic trunks.
thoracic duct (ductus thoracicus) is the largest and main collector of lymph:
Ø has a length of 30-40 cm;
Ø is formed at the level - as a result of the merger of the right and left lumbar trunks;
Ø the initial part of the duct may have an extension - the lactiferous cistern ( cistern chili);
Ø from the abdominal cavity, the thoracic duct passes into the chest cavity through the aortic opening of the diaphragm;
Ø leaves the chest cavity through the upper aperture of the chest;
Ø at the level of the thoracic duct forms an arc and flows into the left venous angle or into the final section of the veins that form it (internal jugular and subclavian);
Ø before flowing into the left venous angle, the left bronchomediastinal trunk, the left jugular trunk and the left subclavian trunk join it.
Thus, along the thoracic duct, lymph flows from ¾ of the human body:
Ø lower limbs
Ø walls and organs of the pelvis
Ø walls and organs of the abdominal cavity
Ø of the left half of the chest cavity
Ø left upper limb
Ø left side of the head and neck
Right lymphatic duct(ductus lymphaticus dexter):
intermittent, absent in 80% of cases
has a length of 10-12 cm
It is formed as a result of the fusion of the right bronchomediastinal trunk, the right jugular trunk and the left subclavian trunk
flows into the right venous node or into one of the veins that form it
· drains the right side of the head, neck, chest, right upper limb, i.е. a pool is ¼ of the human body.
Factors that ensure the movement of lymph:
Continuity of lymph formation
suction property of the thoracic cavity, subclavian and internal jugular veins
contraction of skeletal muscles, pulsation of blood vessels
diaphragm contraction
contraction of the muscular walls of medium and large lymphatic vessels, trunks, ducts
presence of valves.
22. General principles of the structure and function of the lymphatic system.
lymphatic system (systemalymphaticum) includes branched capillaries in organs and tissues, lymphatic vessels, lymph nodes, which are biological filters for tissue fluid, as well as lymphatic trunks and ducts. Through the lymphatic vessels, lymph (tissue fluid) flows from the place of its formation to the confluence of the internal jugular and subclavian veins, which form the venous angle on the right and left in the lower parts of the neck.
The lymphatic system performs the most important protective functions in the body - it filters the tissue fluid (through the lymph nodes) and returns it (purified) to the blood, and then back to the organs and tissues. With the help of the lymphatic system, particles of dead cells and other tissue elements, coarse proteins that are not able to pass through the walls of blood capillaries, as well as foreign particles and microorganisms trapped in the human body are removed from organs and tissues.
According to the structure and functions in the lymphatic system, lymph capillaries(lymphocapillary vessels). They absorb tissue fluid, which, together with crystalloids dissolved in it, metabolic products in the lymphatic capillaries, is called lymph(from lat. lympha - clear water). In its composition, lymph practically does not differ from tissue fluid. It is colorless, it contains a certain amount of lymphocytes, macrophages are found.
By lymphatic vessels lymph from the capillaries, together with the substances contained in it, flows to the regional lymph nodes corresponding to a given organ or part of the body, and from them to large lymphatic vessels - trunks and ducts. Lymphatic vessels can serve as pathways for the spread of infection and tumor cells.
lymph trunks And lymphatic ducts- these are large collector lymphatic vessels, through which lymph flows from the areas of the body to the lower parts of the neck - to the final sections of the subclavian or internal jugular vein or to the venous angle - the place where these veins merge. As a result of this fusion, the right (left) brachiocephalic vein is formed.
Lymph flowing through the lymphatic vessels to the lymphatic trunks and ducts passes through the lymph nodes, which perform barrier-filtration and immune functions. In the sinuses of the lymph nodes, lymph is filtered through loops of reticular tissue.
23. Thoracic duct: formation, parts, topography, tributaries.
The largest and most important lymphatic vessel is thoracic duct. Through it, lymph flows from the lower extremities, walls and organs of the pelvis, abdominal cavity, and the left half of the chest cavity. From the right upper limb, the lymph is directed to right subclavian trunk, from the right half of the head and neck - in right jugular trunk, from the organs of the right half of the chest cavity - in right bronchomediastinal trunk(tnincus bronchomediastinalis dexter), flowing into right lymphatic duct or independently in the right venous angle (Fig. 46). Lymph flows from the left upper limb through left subclavian trunk, from the left half of the head and neck - through left jugular trunk, and from the organs of the left half of the chest cavity - in left bronchomediastinal trunk (tnincus bronchomediastin Alis sinister), which flows into the thoracic mouth.
thoracic duct (ductus thoracicus) is formed in the abdominal cavity, in the retroperitoneal tissue, at the level of CP of the chest - II lumbar vertebrae as a result of fusion right and left lumbar lymphatic trunks(triinci lumbales dexter et sinister). These trunks, in St.< ю очередь, образуются из слияния выносящих лимфатических сосудов соответственно правых и левых поясничных лимфатических узлов. Примерно в 25 % случаев в начальную часть грудного протока впадает один-три выносящих лимфатических сосуда брыжеечных лимфатических узлов, которые называют кишечными стволами (tninci in- testinales). В грудной проток впадают выносящие лимфатические сосуды предпозвоночных, межреберных, а также висцеральных (предаортальных) лимфатических узлов грудной полости. Длина грудного протока составляет 30-40 см.
The abdominal part (p£rs abdominalis) of the thoracic duct a is its initial part. In 75% of cases, it has an extension - the cistern of the thoracic duct (cisterna chyli, lactiferous cistern) of a cone-shaped, ampudoid or fusiform shape. In 25% of cases, the beginning of the thoracic duct looks like a reticular plexus formed by the efferent lymphatic vessels of the lumbar, celiac, mesenteric lymph nodes. The walls of the cistern of the thoracic duct are usually fused with the right crus of the diaphragm, which, during respiratory movements, compresses the thoracic duct and helps to push the lymph through. From
In the abdominal cavity, the thoracic (lymphatic) duct passes through the aortic opening of the diaphragm into the chest cavity, into the posterior mediastinum, where it is located on the anterior surface of the spinal column, behind the esophagus, between the thoracic aorta and the azygous vein.
The thoracic part (pars thoracica) of the thoracic duct is the longest. It extends from the aortic opening of the diaphragm to the upper aperture of the chest, where the duct passes into its upper cervical part (pars cervicalis). In the lower parts of the chest cavity, behind the thoracic duct, there are the initial sections of the right posterior intercostal arteries and the final sections of the veins of the same name, covered by the intrathoracic fascia, in front - the esophagus. At the level of the VI-VII thoracic vertebrae, the thoracic duct begins to deviate to the left, at the level of the II-III thoracic vertebrae it exits from under the left edge of the esophagus, rises up behind the left subclavian and common carotid arteries and the vagus nerve. Here, in the upper mediastinum, to the left of the thoracic duct are the left mediastinal pleura, to the right is the esophagus, and behind is the spinal column. Lateral to the common carotid artery and behind the internal jugular vein at the level of the V-VII cervical vertebrae, the cervical part of the thoracic duct bends and forms an arc. The arc of the thoracic duct (arcus ductus thoracici) goes around the dome of the pleura from above and somewhat behind, and then the mouth of the duct opens into the left venous angle or into the final section of the veins that form it (Fig. 47). In about 50% of cases, the thoracic duct has an expansion before flowing into a vein. Also, the duct often bifurcates, and in some cases, in the form of 3-4 trunks, it flows into the venous angle or into the terminal sections of the veins that form it.
At the mouth of the thoracic duct there is a paired valve formed by its inner shell, which prevents the blood from being thrown from the vein. Throughout the thoracic duct, there are 7-9 valves that prevent the reverse flow of lymph. The walls of the thoracic duct, in addition to inner shell(tunica interna) and outer shell(tunica externa) contain a well-defined middle (muscular) membrane(tunica media), capable of actively pushing the lymph along the duct from its beginning to the mouth.
In about a third of cases, there is a doubling of the lower half of the thoracic duct: next to its main trunk, there is an additional thoracic duct. Sometimes local splitting (doubling) of the thoracic duct is found.
The lymphatic system is a part of the cardiovascular system that complements it. It performs the most important functions in the human body, and its health is extremely important for its normal functioning. Lymph differs from blood in that it does not flow in a closed circle. Its movement is very slow, so it needs to be stimulated.
Interesting fact! In ancient times, the lymphatic system was considered as the main factor that determines human temperament. Temperament, in turn, determined the groups of diseases to which a person is susceptible.
What is the lymphatic system?
According to anatomy permeates the entire body. It consists of:
- capillaries;
- vessels;
- nodes;
- lymphatic ducts and trunks;
- lymphatic organs.
Liquid connective tissue flows through them - lymph, the main composition of which is water, salts, proteins, fats. Its composition is close to the blood plasma that nourishes the body. Lymph is colorless. In the human body it contains from 1 to 2 liters.
How does lymph formation occur?
Lymph formation occurs in the following way. In the blood capillaries, blood plasma is filtered. The fluid remaining as a result of this filtration is transported into the intercellular space. Thus, tissue fluid is formed, part of which returns to the blood, and the other part passes into the lymphatic capillaries. Its movement largely depends on muscle contraction, the position of the human body and his breathing.
That's how complex it is - human anatomy. The lymphatic system and its structures are thought out by nature to the smallest detail. Consider this component of the human body in more detail.
The structure of the lymphatic system
Lymphatic capillaries are small tubes of different diameters, devoid of a membrane, which begin blindly. They form connections by intertwining with each other, passing into postcapillaries, which are larger formations containing valves. These valves push the lymph in one direction, preventing it from moving back.
Attention! The word "lymph circulation" is incorrect, because lymph is a product of the endothelium and interendothelial layers, each time being updated in the body. Doctors call this process lymph drainage.
According to the section of biology called "human anatomy", the lymphatic system also consists of vessels that form from postcapillaries. The largest of them follow the path of veins and arteries and are called collectors. They collect lymph from the largest sources - upper and lower extremities, organs. They are divided into internal (located near blood vessels) and external (located in the subcutaneous tissue). Also, the vessels are divided into afferent and efferent (depending on the flow of lymph in relation to the lymph nodes).
From the collectors, lymphatic trunks are formed, which are converted into ducts.
The lymph nodes
The human lymphatic system (anatomy has not paid due attention to this component of our body for a long time) also has its own “cleaners”. Lymph nodes are small, round or oval-shaped formations about 2 cm in diameter. They are pinkish-gray in color. They are located along the lymphatic vessels. In young people, oval-shaped lymph nodes predominate, while in older people they are elongated. Their main function is to cleanse the lymph from toxic substances that enter there. Lymph nodes play the role of a kind of filter that captures toxins and “releases” already cleansed lymph.
The lymphatic organs are the spleen, tonsils, and thymus (which develops before adolescence). Their main functions are to prevent the entry and development of infection in the body.
What are the functions of the lymphatic system in the body?
One of the most complex and confusing sciences is human anatomy. The lymphatic system, whose functions are very important for the body, does a great job.
First of all, it is responsible for the immune response of the body, protecting it from bacteria and viruses. That is why, in response to the penetration of the pathogen into the body (infection, virus), the lymph nodes increase. It is their increase in children that indicates the presence of, say, tuberculosis, although, in addition to this, lymph nodes increase in many other diseases. The protective function consists of two stages:
- destruction of bacteria by macrophages;
- production of lymphocytes.
Blood filtration. The spleen destroys red blood cells and kills all bacteria and viruses it finds in the blood. Young red blood cells are produced by the bone marrow.
Lymph filtration. If there are pathogenic microorganisms in the blood, then the lymph nodes filter them out. It is for this reason that when oncology is suspected, doctors first of all check the lymph nodes for the presence of metastases. The human lymphatic system (anatomy is briefly discussed) in this case indicates how much the disease has spread throughout the body.
The outflow of fluid from the tissue into the blood. Plasma, which is part of the blood, seeps through the walls of blood vessels into other tissues. It passes through to be cleansed and returned to the blood again. This circulation is continuous.
Diseases of the lymphatic system
According to human anatomy, the lymphatic system is extremely important for the health of the body, and violations of its work can cause serious complications.
Among the groups of diseases of the lymphatic system are:
- malformations;
- trauma;
- inflammation;
- tumors.
One of the first symptoms of these diseases is an increase in lymph nodes and a noticeable decrease in immunity. Sweating and fatigue increase, patients are disturbed by a headache, the temperature can rise. Lymph diseases are especially dangerous because toxins begin to accumulate in the body. That is, a violation of its activity affects all organs and systems of the body.
Methods of treatment of pathologies of the lymphatic system directly depend on the type of disease. Treatment can be different - from conservative to radiation or surgical methods.
We hope that people who are interested in human anatomy, the lymphatic system (photos showing how complex this component of our body is presented in the article) and its functions have learned a lot of new and interesting things about this environment of the body. How to keep her healthy?
Lymphatic health
First of all, doctors recommend that you monitor your health and prevent disruptions in the digestive tract, as this entails pollution of the entire body and interferes with the functioning of the lymphatic system. She can no longer cope with the flow of toxins. Watch your diet.
Massage twice a year. Such a procedure effectively accelerates the lymph, but it is especially effective which acts directly on the lymph. If it is not possible to visit a massage therapist, in the shower, rub the body with a washcloth over the lymph flow.
Control your weight. Lymph is very sensitive to extra pounds. Lead an active lifestyle and be healthy!
