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 parts of the personal emergency system, each of which is responsible for filtering clear liquid (lymph) from harmful substances.
It is impossible to say unequivocally what the lymphatic system is needed for, 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 are significantly different from each other. There are no red blood cells in the clear liquid, and there are much fewer protein molecules than in blood. The LSC is not closed. It lacks the main pump, i.e. the heart. Lymph moves into the LSF smoothly and under minimal pressure.
The structure of the human lymphatic system will be shown in the diagram. She will also indicate the features of lymph movement. The components of the most important part of the body are described in detail below.
Lymph
The word "lymph" is translated from Latin as "clean water". This is not surprising, because this liquid cleanses the body of harmful substances. In its structure, lymph is connective tissue and has many lymphocytes, practically no platelets and red blood cells.
The composition of “pure water” includes waste products of the body, including large protein molecules. Most often they are viruses that are filtered by the lymph 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 occurs through formations - lymph nodes, which perform the function of filtration. In total, the lymphatic system contains about 500 such anatomical structures.
Lymphatic vessels and capillaries
Click to enlarge
The LSP looks like the roots of a tree. This brings it closer to the nervous and circulatory systems. Lymphatic vessels penetrate almost the entire human body, excluding the sclera, the inside of the ear and some other segments.
From tissues, lymph comes into capillaries, which connect into lymph vessels. The latter surround all organs and often lie in several layers.
Through the vessels, lymph passes to the regional links of immunity, localized in the groin and elbow areas, armpits, chest, etc. Large trunks emerge from the nodes, which flow into ducts, opening the way for “clean water” into the circulatory system.
Lymph nodes (immune links)
A lymph node (LN) is often a round formation, gray-pink in color and measuring from 0.5 to 50 mm or more. Immune links are localized along the lymphatic and near blood vessels. Each of the formations serves as a kind of filter. They are responsible for cleansing the body not only of microbes, but also of 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;
- cortex, consisting of a superficial part and a deep cortex.
At the heart of the immune system is lymphoid tissue, which contains lymphocytes, reticulocytes and plasma cells. The formations develop the most important components of immunity - B-lymphocytes, which participate in its formation.
Functions of the lymphatic system
Lymphocytes actively fight bacteria and viruses entering the body from the outside. This ensures the normal functioning of the body's defenses. Immune links increase if the number of microbes is too large and they cannot cope with them. In this case, the help of a specialist is required.
The lymphatic system performs the function of cleansing microbes and is responsible for delivering essential elements to the venous bed. Later, these components enter the cardiovascular system through blood circulation and leave the human body.
Most harmful substances are eliminated at the stage of filtration by a transparent liquid, i.e. they are destroyed in the immune system. The body “works” normally thanks to the lymphatic capillaries, through which proteins and other compounds come from the interstitial space into the clear liquid.
How “clean 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's - LSP cancer with a high degree of malignancy;
- non-Hodgkin (B-cell or T-cell).
- Lymphadenitis - inflammation of the immune system:
- 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 persistent swelling of a limb that develops as a result of damage to the lymph nodes, which contributes to impaired lymph circulation or the formation of lymphostasis.
Signs of a 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 the following are useful:
- physical activity;
- trampolining;
- yoga classes;
- proper diet;
- breathing exercises;
- rejection of bad habits;
- nutrition according to Ayurveda.
If the cleansing function is disrupted, health problems arise. A person needs continuous work of a medical device. His well-being depends on how the structures cope with their task. To maintain health, lymph is needed periodically.
Which doctor should I contact?
Treatment of LSP pathologies comes down to the use of medications or surgery. If you find deviations from the norm, you need to consult a pediatrician/therapist, who will refer you to a specialist.
Below is a table explaining which doctors deal with medical conditions.
| Leading symptom | Subspecialist |
| Enlarged lymph nodes in the neck | Otorhinolaryngologist |
| Soreness and proliferation of lymphoid tissue under the jaw | Dentist |
| Increased immune links in the groin area | Gynecologist or urologist |
| Change in the size of formations, accompanied by hemoptysis, sudden weight loss, increased sweating, fever |
The lymphatic system, which in Latin is called systema lymphatica, performs important functions in the human body 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 functions as 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 removes tissue fluid from the intercellular space. This 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 lymph system. However, few understand the essence of such a process. This is a complex open 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. There are about 460 grouped or single lymph nodes in different parts of the body along the lymphatic vessels in the human body. Groups of lymph nodes work constantly. They are located next to veins and arteries. This number of lymph nodes is enough for the human body to feel healthy. These vessels are connected to each other by lymph nodes.
Small and large vessels are grouped. These are groups with different lymph nodes. They are sent to the lymph nodes (lat. nodi lymphatici), which range 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 area of the body. The weight of all lymph nodes is 1% of body weight, reaching 1 kg. Lymphocytes, necessary to fight infection, are produced in the lymph nodes.
Lymphatic capillaries form the basis of this system. They are everywhere. These thin capillaries collect the fluid that is there in the body. This biological fluid contains various beneficial and harmful toxic substances. These toxins (lat. Toxicum) poison our body, so the lymphatic system collects these substances in the body.
Lymph is the liquid 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 and destroy their toxins.
Platelets and red blood cells are absent in the lymph. It is constantly formed by filtering blood plasma. This colorless liquid always circulates in this system. Up to 2 liters of this transparent biological fluid circulates in the body of an adult. Lympha moves slowly under slight pressure. Lymph always flows from bottom to top. This biological fluid slowly carries tissue fluid from the toes of the lower extremities to the thoracic lymphatic duct. Only in this direction can lympha collect everything unnecessary in the body and remove it out.
Lymphatic capillaries have special valves that prevent the reverse flow of lymph. Lympha purifies the blood in the human body. However, sometimes these valves in a person are destroyed, and the flow of lymph slows down. During an infectious process on the hand, the ulnar lymph nodes become inflamed. In these situations, swelling of the limbs occurs.
This indicates damage to the lymphatic vessels. How does lymph flow? Microcirculation processes determine the volume and rate of lymph formation. When there is obesity, or a person sits for a long time, the movement of 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.
Importance of the Lymphatic System
Structure of the lymphatic system
What is the location of the lymph nodes? The structures of the systema lymphatica are not capable of removing waste and poisons through the skin. In our body there are such organs with a mucous membrane. A group of lymph nodes release these toxins into a specific area to remove the 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.
Operation
Lymph nodes in the abdominal cavity
Patients complain of the appearance of some pathological discharge. Lymphocytes cleanse the vagina, urethra, and male genitalia. The femoral triangle consists of. The destruction of microbes is accompanied by inflammation. The deep lymph nodes are compressed, the thigh hurts. When the toxins come out, the body will be clean.
The second area of poison evacuation is the intestines. There are many lymph nodes in the abdomen. If the body is poisoned due to improper nutrition, the lymph nodes remove toxins through the lymph nodes located in the intestines. In the chest and abdominal cavity there is a group of para-aortic lymph nodes. If you start taking fixative medications during diarrhea, these toxins will remain in the affected body.
sweat glands Sweat glands are another area of toxin evacuation. There are especially many of them in the armpits. A 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 a 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. Pathogens that entered by airborne droplets are eliminated through the nose. If a person is treating himself, vasoconstrictor drops are often used. Instead of removing the pathological contents, the patient leaves the microbes in the body. A sign of damage to the system are symptoms of sinusitis.
The nasopharynx has a special lymphoid tissue that traps microbes. Staphylococcal infections always exit through the nasal cavity. If it is not possible to quickly cope with an airborne infection, the adenoids enlarge. The lymph nodes of 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, and tongue is carried out by the mental lymph nodes. Lymphadenitis is inflammation of the lymph nodes of the face. Part of the systema lymphatica are the salivary glands. Together with oral fluid, toxins and poisons are carried into the digestive tract for removal from the body. When the jaw lymph nodes are affected, the lower jaw hurts greatly. It is important to make swallowing movements. This stimulates saliva production.
inflammation of the tonsils The palatine tonsils stand guard, protecting the body. This is the place through which the body can remove all the bad things. Streptococcus is always excreted through the tonsils. The body fights, which is why sore throat and rheumatism occur. But if a person violates the laws of a healthy life, the tonsils are constantly inflamed.
When the lymph nodes on the face are affected, the chin hurts. Tonsillitis develops, the tonsils cannot cope with their work. Inflamed submandibular lymph nodes receive infection from the facial lymph node. In the case of tonsillectomy unless absolutely necessary, another barrier that protects human health disappears.
The larynx is the next barrier to infection. If the lymphatic system finds microbes and removes them through the larynx, laryngitis develops. In the ear area, the facial lymph nodes 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 leave 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 route of the systema lymphatica is the bronchi. It is a significant component of the immune system. The passage of infection is further blocked by the lymph nodes with the help of tracheal lymph. The fungus is released through nearby organs. Fungal bronchitis begins if the pathogen affects the entire body. If you take cough pills during bronchitis, mucus does not come out of the bronchi. The disease drags on and the patient's condition worsens. As a result of the sedimentation 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. Lymphatic capillaries in the lungs often take the first blow of infection. They are called bronchopulmonary lymph nodes. Through the deep and superficial plexuses of the lungs, the respiratory organ is cleansed. The dangerous bacteria enters the lymph node area. This is where it is destroyed. With 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. Enlarged lymph nodes in the neck may indicate hard work of the systema lymphatica. Non-functioning facial lymph nodes often cause severe muscle blocks, since lymph flow is obstructed. The sublingual lymph node reacts sensitively to any changes in the body.
Lymphatic system. Video
Complications of lymphatic function
If the lymph system is overloaded and a new infection enters the body, problems arise. Systema lymphatica releases debris into the skin because the system is clogged with other toxins. Breast cancer can provoke metastases to the subclavian lymph nodes. The body tries to remove the fungus through the skin. However, the dense epidermis does not allow harmful substances to pass out. Eczema, psoriasis, and neurodermatitis occur. These are not diseases, but a painful condition, a manifestation of problems with an overloaded lymphatic system. It is necessary to cleanse the body.
body cleansing Poor environment, poor lifestyle, poor quality food harm the health of every person. After the age of 30, many people's body fluids become heavily contaminated. Fat cells and tissues can contain many different toxins, microorganisms, and 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. The movement of lymph is ensured through various muscles. Lympha is able to fully function only if a person is physically active. After a long period of sitting, it is important to move actively. At the same time, normal lymph flow starts. 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.
White blood cells 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. Main structural elements of the lymphatic system
III. Pathways for lymph drainage 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 bed.
2. Resorption function– together with lymph, colloidal solutions of proteins, lipids, and foreign agents (bacteria, viruses, foreign bodies) are removed from the tissues.
3. Lymphopoietic function– Lymphocytes are formed in lymph nodes.
4. Immunological function– provides humoral immunity by forming antibodies.
5. Barrier function– neutralizes foreign agents (bacteria, viruses, malignant cells, foreign bodies).
Lymph- transparent yellowish liquid, contains blood cells - lymphocytes, as well as a small number of eosinophils and monocytes. In its composition, lymphoplasm resembles blood plasma, but differs in lower protein content and 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 microcircular bed, where lymphatic capillaries are in close contact with blood vessels.
Features of the structure of the lymphatic system:
· the lymphatic system is not functionally closed - the lymphatic capillaries begin blindly.
· the presence of valves in the lymphatic vessels that prevent the reverse flow of lymph.
· lymphatic pathways are intermittent (interrupted by lymph nodes).
II. The main structural elements of the lymphatic system.
Lymphatic capillaries
Lymphatic vessels
The lymph nodes
Lymphatic trunks
Lymphatic ducts
1. Lymphatic capillaries– are the initial link, the “roots” of the lymphatic system. They are characterized by:
Ø they begin blindly, due to which 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 µm) compared to hemocapillaries (5-7 µm);
Ø the presence of filaments - bundles of fibers connecting capillaries with collagen fibers. During 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 they are 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 participate 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, the vascular wall contains a layer of smooth muscle cells and connective tissue;
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 section of the lymphatic vessel between the valves, intervalvular systems;
Ø have lymph nodes along the way
By topography
o intraorgan, forming a plexus;
o extraorganic.
In relation to the superficial fascia, lymphatic vessels (extraorgan) can be:
o superficial(located outward from the superficial fascia, next to the saphenous veins);
o deep(located under its own fascia, accompanying deep vessels and nerves).
In relation to the lymph node lymphatic vessels can be:
o bringing(lymph flows through them to the lymph node);
o outgoing(lymph flows from the lymph node).
3. Lymph nodes located along the path of the lymphatic vessels. The nodes relate to both the lymphatic and immune systems.
Functions of lymph nodes:
Ø lymphopoietic– produce lymphocytes
Ø immunopoietic- antibody production, activation of B lymphocytes
Ø barrier-filtration– retain foreign agents (bacteria, viruses, tumor cells, foreign bodies). Those. lymph nodes are mechanical and biological filters of lymph
Ø propulsive function– promotes lymph, since the capsule of the lymph nodes contains elastic and muscle fibers.
Tumor cells can multiply in the lymph nodes, leading 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 along the lymph path. 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 blood, increasing metastases.
External structure of lymph nodes:
Ø Nodes are usually located in groups from one to several hundred
Ø the nodes are pink-gray, round, 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 proliferation of lymphocytes)
Ø afferent lymphatic vessels approach the convex side of the node. The efferent vessels emerge from the loop depression - the gate of the node.
Internal structure of lymph nodes:
Ø connective tissue capsule covers the outside of the lymph node
Ø capsular trabeculae extend from the capsule into the node and perform a supporting function
Ø reticular tissue (stroma) fills the space between trabeculae and contains reticular cells and fibers
Ø the parenchyma of the lymph node is divided into cortex and medulla
Ø The cortex is located closer to the capsule. Lymph nodes are located in the cortex, where proliferation and differentiation of B lymphocytes occur
Ø the medulla occupies the central part of the lymph node, represented by strands of lymphoid tissue, where B-lymphocytes mature and transform into plasma cells
Ø the medulla together with the lymph nodes of the cortex form the B-dependent zone
Ø at the border of the lymph nodes with the medulla there is a paracortical zone (thymus dependent, T-zone), where maturation and differentiation of T-lymphocytes occurs
Ø The cortex and medulla are penetrated by a network of lymphatic sinuses, through which lymphocytes and macrophages can penetrate in both directions.
Afferent vessel subcapsular sinus cortical sinus medullary sinus portal sinus efferent vessels
4. Lymphatic trunks– large lymphatic vessels (collectors) that collect lymph from several areas of the body and organs. They are formed when the efferent vessels of the lymph nodes merge and exit into the thoracic duct or the right lymphatic duct.
Lymphatic 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, inconsistent, 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 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 fusion of the right and left lumbar trunks;
Ø the initial part of the duct may have an extension - the lacteal 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 thoracic aperture;
Ø at the level of the thoracic duct forms an arc and flows into the left venous angle or into the terminal section of the veins that form it (internal jugular and subclavian);
Ø before entering the left venous angle, it is joined by the left bronchomediastinal trunk, the left jugular trunk and the left subclavian trunk.
Thus, lymph flows from ¾ of the human body through the thoracic duct:
Ø lower limbs
Ø walls and pelvic organs
Ø walls and organs of the abdominal cavity
Ø left half of the thoracic cavity
Ø left upper limb
Ø left half of head and neck
Right lymphatic duct(ductus lymphaticus dexter):
· inconsistent, absent in 80% of cases
· has a length of 10-12 cm
· formed as a result of the fusion of the right bronchomediastinal trunk, right jugular trunk and left subclavian trunk
· flows into the right venous node or into one of the veins forming it
· drains the right side of the head, neck, chest, right upper limb, i.e. The pool is ¼ of the human body.
Factors ensuring lymph movement:
continuity of lymph formation
· suction property of the chest cavity, subclavian and internal jugular veins
contraction of skeletal muscles, pulsation of blood vessels
contraction of the diaphragm
· 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 capillaries branched in organs and tissues, lymphatic vessels, lymph nodes, which are biological filters for tissue fluid, as well as lymphatic trunks and ducts. Through lymphatic vessels, lymph (tissue fluid) flows from the place of its formation to the confluence of the internal jugular and subclavian veins, forming a 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 tissue fluid (through the lymph nodes) and returns it (purified) to the blood, and then again to organs and tissues. With the help of the lymphatic system, particles of dead cells and other tissue elements, coarse proteins that are unable to pass through the walls of blood capillaries, as well as foreign particles and microorganisms found in the human body are removed from organs and tissues.
According to the structure and functions in the lymphatic system, they are divided into lymphatic capillaries(lymphocapillary vessels). Tissue fluid is absorbed into them, which, together with crystalloids dissolved in it, metabolic products in the lymphatic capillaries, is called lymph(from Lat. lympha - clean water). In its composition, lymph is practically no different from tissue fluid. It is colorless, it contains a certain number of lymphocytes, and macrophages are found.
By lymphatic vessels lymph from the capillaries, together with the substances it contains, flows to the regional lymph nodes corresponding to a given organ or part of the body, and from them to the large lymphatic vessels - trunks and ducts. Lymphatic vessels can serve as pathways for infection and tumor cells to spread.
Lymphatic trunks And lymphatic ducts- these are large collector lymphatic vessels through which lymph flows from areas of the body to the lower parts of the neck - to the terminal sections of the subclavian or internal jugular vein or to the venous angle - the confluence of these veins. 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 main lymphatic vessel is thoracic duct. Lymph flows through it 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, lymph is directed to right subclavian trunk, from the right half of the head and neck - to 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 into 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 thoracic cavity - to left bronchoredestinal trunk (tnincus bronchomediastin Alis sinister), flowing into the thoracic mouth.
Thoracic duct (ductus thoracicus) is formed in the abdominal cavity, in the retroperitoneal tissue, at the level of the thoracic CP - 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 is its initial part. In 75% of cases, it has an expansion - the thoracic duct cistern (cistern chyli, milky cistern) of a cone-shaped, ampud-shaped or fusiform shape. In 25% of cases, the beginning of the thoracic duct has the form of a reticular plexus formed by the efferent lymphatic vessels of the lumbar, celiac, and mesenteric lymph nodes. The walls of the thoracic duct cistern are usually fused with the right leg of the diaphragm, which, during respiratory movements, compresses the thoracic duct and promotes the pushing of lymph. From
of 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 part of the aorta and the azygos vein.
The thoracic part (pars thoracica) of the thoracic duct is the longest. It extends from the aortic opening of the diaphragm to the superior thoracic aperture, where the duct passes into its upper cervical part (pars cervicalis). In the lower parts of the thoracic 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, and the esophagus in front. 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 emerges 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 there is 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 arch. The arc of the thoracic duct (arcus ductus thoracici) bends 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 terminal section of the veins that form it (Fig. 47). In approximately 50% of cases, the thoracic duct is dilated before entering the vein. The duct also often bifurcates, and in some cases, in the form of 3-4 stems, 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 membrane, which prevents the flow of blood from the vein. Along 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) layer(tunica media), capable of actively pushing lymph along the duct from its beginning to the mouth.
In approximately a third of cases, duplication of the lower half of the thoracic duct occurs: next to its main trunk there is an accessory thoracic duct. Sometimes local splitting (duplication) 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 the main factor determining human temperament. Temperament, in turn, determined the groups of diseases to which a person was susceptible.
What is the lymphatic system?
As reported, anatomy permeates the entire body. It includes:
- 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. The human body contains from 1 to 2 liters.
How does lymph formation occur?
Lymph formation occurs in the following way. Blood plasma is filtered in the blood capillaries. The liquid remaining as a result of this filtration is transported into the intercellular space. In this way, 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 person’s body and his breathing.
This is how complex it is - human anatomy. The lymphatic system and its structure are thought out by nature to the smallest detail. Let us consider this component of the human body in more detail.
Structure of the lymphatic system
Lymphatic capillaries are small tubes of different diameters, lacking a membrane, which begin blindly. They form connections by intertwining with each other, passing into postcapillaries, which are larger structures containing valves. These valves push lymph in one direction, preventing it from flowing back.
Attention! The word “lymph circulation” is incorrect, because lymph is a product of the endothelium and interendothelial layers, each time being renewed in the body. Doctors call this process lymphatic drainage.
According to the section of biology called "human anatomy", the lymphatic system also consists of vessels that are formed from post-capillaries. 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 and organs. They are divided into internal (located near blood vessels) and external (located in the subcutaneous tissue). Vessels are also 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 transformed into ducts.
The lymph nodes
The human lymphatic system (anatomy for a long time did not pay due attention to this component of our body) also has its “cleaners”. Lymph nodes are small round or oval-shaped formations, the diameter of which is about 2 cm. They have a pinkish-gray tint. 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 purified lymph.
The lymphatic organs are the spleen, tonsils and thymus (which develops until adolescence). Their main functions are to prevent infection from entering and developing in the body.
What functions does the lymphatic system perform 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, performs a huge job.
First of all, it is responsible for the body’s immune response, protecting it from bacteria and viruses. That is why, in response to the penetration of a pathogen (infection, virus) into the body, the lymph nodes enlarge. It is their increase in children that indicates the presence of, say, tuberculosis, although, in addition to this, lymph nodes enlarge in many other diseases. The protective function consists of two stages:
- destruction of bacteria using macrophages;
- production of lymphocytes.
Blood filtration. The spleen destroys red blood cells and kills all bacteria and viruses that 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, the lymph nodes filter them out. It is for this reason that when cancer is suspected, doctors first 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 flow of fluid from tissue into the blood. The plasma contained in the blood seeps through the walls of blood vessels into other tissues. It is cleared 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 disruptions in its functioning can cause serious complications.
Among the groups of diseases of the lymphatic system are:
- developmental defects;
- injuries;
- inflammation;
- tumors.
One of the first symptoms of these diseases is enlarged lymph nodes and a noticeable decrease in immunity. Sweating and fatigue increase, patients suffer from headaches, and the temperature may rise. Lymph diseases appear are especially dangerous because toxins begin to accumulate in the body. That is, disruption of its activity affects all organs and systems of the body.
Treatment methods for 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 demonstrating 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 monitoring your health and preventing disturbances in the functioning of the gastrointestinal tract, as this entails contamination 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.
Get a massage twice a year. This procedure effectively disperses the lymph, but it is especially effective if it acts directly on the lymph. If it is not possible to visit a massage therapist, in the shower, rub your body with a washcloth along the lymph flow.
Control your weight. Lymph is very sensitive to extra pounds. Lead an active lifestyle and be healthy!
