What is the lymph nodes: location, structure and size. Causes of enlarged lymph nodes

What are lymph nodes? An exhaustive answer to the question you ask is found in the article. In addition, we will talk about the structure of the organ presented, as well as the causes of its inflammation, possible consequences, and so on.

General information

What are lymph nodes? A lymph node is the peripheral organ of the lymphatic system, which acts as a natural filter. Through it flows all the lymph, coming from various parts and organs of the body. In the human body, several groups of such nodes are distinguished, which are called regional ones.

Size of lymph nodes

Externally, the lymph nodes look like rounded, oval, bean-shaped or sometimes ribbon-like formations. Their sizes range from 0.5 to 50 millimeters or more. As you know, these peripheral organs are painted in a grayish pink color. Lymph nodes are only in the course of lymphatic vessels and are clustered up to ten pieces near large veins and blood vessels.

Appearance

Lymphonoduses of the person are covered with a connective tissue covering, from which the so-called trabeculae or beams leave the body. They are original support structures. It should be specially noted that the peripheral organ itself, which functions as a natural filter, consists of a stroma. It is formed from the reticular connective tissue, on which there are process cells that form a three-dimensional network. In addition, the stroma consists of phagocytic substances (or macrophages), represented in lymph nodes by several species.

Internal structure of the lymph node

At the cut of the lymph nodes, two main zones are immediately distinguished. Closer to the shell is a cortical substance. In it, the surface part and the deep crust region (or the so-called paracortical layer) are distinguished. To the inner zone of the lymph node is the brain substance.

The entire space of this organ is filled with lymphoid tissue. In the area of the surface cortex, which is closer to the shell, small nodules or follicles are located. It should be noted that they have a central lighter part (germinative center) where B-lymphocyte differentiation and antigen-dependent proliferation occur, as well as a dark surface that contains a large number of closely packed and rather small lymphocytes.

Principle of operation

In the paracortical zone, lymphocytes are located evenly and very tightly. In this part of the body, T lymphocytes predominate. Here they undergo antigen-dependent differentiation and proliferation. As for the brain substance, the clusters of lymphoid tissue in it are represented by cerebral strands (or flesh cords), where B-lymphocytes migrate from the surface cortex.

The principle of operation of this peripheral organ is as follows: lymph flows to the nodes along vessels that are suitable from the convex side, and flows out along the vygnosyaschimi with the concave part. At the same time, lymph slowly penetrates the spaces called sines. They are located between the membrane and trabeculae, as well as lymphoid tissue.

Just like the vessels, the inner space of the node has its own lining, which is formed by littoral or coastal cells. As a rule, their processes are directed into the sinus, where they begin to contact the reticular cells. It should be specially noted that unlike conventional vessels, sinuses do not have a free cavity, because it is completely blocked by a three-dimensional network. Due to this structure, lymph, getting into the node, slowly percolates, which contributes to its thorough cleansing from foreign bodies. This process is also due to macrophages located at the very edge of lymphoid clusters. By the way, during passage through the sinuses (brain substance), the lymph is fully saturated with antibodies that produce plasmatic cells (the brain).

What are the lymph nodes for?

What is the lymph nodes, we found out. Now I want to tell you about what these organs need in general. The fact is that the flowing lymph brings to the node so-called foreign antigens. As a result, this leads to the development of an immune response in the response organs. Depending on the type and nature of foreign bodies, such reactions can actively develop in external or internal zones. This leads to a barely noticeable or strong increase in the size of the nodes. Thus, it can be safely noted that the presented peripheral organs are a kind of barrier for the spread of not only various infections, but also a cancerous tumor. After all, protective cells that are active in destroying foreign antigens and other substances are able to mature in a node.

Where are the lymph nodes located?

Lymphonoduses (photos are presented in this article) are in the human body rather large groups, which number about ten pieces. They are located so as to prevent the development of various infections and cancer. It is for this reason that the nodes are located near the most important organs and systems for life, namely in the elbow and knee folds, in the armpits and inguinal region. In addition, they are located in the neck, chest and abdomen. Thus, the lymph nodes provide complete protection against various infections and head tumors.

Types of lymph nodes

It should be specially noted that such a filtration system is not only in the above places. Lymphocapillaries permeate all internal organs. In doing so, they perform the same functions.

So, in the human body there are several groups of lymph nodes, namely:

• Intrathoracic;
• Bronchopulmonary;
• Ulnar;
• Splenic;
• Para-aortic;
• Mesenteric;
• Iliac (external, internal, as well as general);
• Inguinal (superficial and deep);
• Femoral;
• Poplites.

Why do lymph nodes increase?

The causes of enlarged lymph nodes are a variety of diseases. At the same time, it should be specially noted that the emerging cone indicates a poor situation in the zone in which it is located. Most of the increase in lymph nodes is associated with any infections. In addition, this pathology occurs against a background of tumor lesion.

So, let's consider in more detail why and under what diseases the lymph nodes increase in children and adults:

• Purulent processes. As a rule, with such a deviation there is a so-called acute lymphadenitis. Most often this occurs as a result of the entry of microbes from wounds that are located in the zone of finding a particular peripheral organ. The main symptoms of this inflammation include the appearance of soreness in palpations and redness of the skin. If, at such a moment, the exposed cone is not opened, the membrane of the node will break, and the pus will penetrate into the surrounding tissues, resulting in a rather serious complication, called phlegmon.
• Enlarged lymph nodes in children quite often indicate the presence of tuberculosis. As a rule, with such a disease, cones are formed in the chest cavity and on the neck.
• Often the cause of enlarged lymph nodes in young children is the Bartonella microbe. The carriers of such a bacterium are cats, whose scratches can often be observed in the child. It is through these wounds that the microbe spreads very quickly through the lymphocytes and enters the nodes, which subsequently increase and become quite painful. Thus, a long non-healing purulent wound, as well as the cone that appeared next to each other, should always suggest the development of a cat scratch disease.
• In ARVI in adults and children can be up to several groups of enlarged lymph nodes. The reason for this deviation is the excessive response of the immune system to the invasion of any viruses in the patient's body. It should be noted that lymph nodes in such situations do not increase very much, but when feeling they are rather painful.
• Venereal diseases, in particular syphilis, also cause enlarged lymph nodes. In this case, the patient can observe cones in the inguinal region, as well as sores on the genitals. Unlike other diseases with syphilis, enlarged lymph nodes can be painless, and accordingly, and invisible to humans.
• Prolonged non-passing groups of lymph nodes may indicate the presence of serious diseases such as listeriosis, brucellosis, HIV infection or mononucleosis.

Increase of nodes in tumors

Tumor swelling may occur due to lymphoproliferative diseases (if the tumor initially originated from the lymph node), as well as from metastatic lesions. The first deviation, first of all, is lymphosarcoma and lymphogranulomatosis. Lymph nodes with such diseases increase to four to five centimeters and become quite dense. However, when feeling, the cones formed are not painful. By the way, with the initial increase of intra-abdominal or intrathoracic lymph nodes such diseases may not be recognized.

Let's sum up the results

Now you know what lymph nodes are. It should be specially noted that an increase in the organs of the peripheral system should immediately alert the patient. The reason for this is simple: this pathological condition indicates that in the human body there are dangerous for his life and health processes. In this case, it is recommended that you immediately consult a doctor and undergo a full medical examination.