Lymph nodes

Synonyms for lymph nodes

lymph gland
Medical = Nodus lymphaticus, Nodus lymphoideus
English = lymph node


Lymph nodes are filter stations in the body's lymphatic system, which transports fluid released from the blood vessels into the tissue back into the bloodstream. The lymph nodes clean this fluid, the lymph, and also play a role in defending against germs.
They are part of the lymphatic system.

Lymph node anatomy

Lymph nodes are kidney-shaped organs that are 2 mm to 2 cm in size and occur everywhere in the body, for example on the neck, in the groin, in the armpits or in the neck.

The lymph node is surrounded by a connective tissue capsule, through which several afferent lymph vessels (vasa afferentia) enter. At the so-called hilar a lymph vessel (vas efferens) leaves the organ and the blood vessels (arteries and veins) enter or exit.

A distinction is made between regional and collective lymph nodes. Regional lymph nodes collect the lymph from a part of the body (e.g. the neck). Collective lymph nodes are connected downstream of these and filter the already purified lymph from several regional lymph nodes.

Illustration lymph nodes and lymph vessels

Figure: Lymph node structure (A) and catchment areas of the lymph nodes (B)

A - Structure of a lymph node

  1. Afferent lymphatic vessels
  2. Flaps against backflow
  3. Cortical zone (paracortex)
  4. Germination center
    (B and T lymphocyte regions)
  5. bar
  6. outer capsule (organ shell)
  7. Tissue fluid (lymph)
  8. Laxative lymphatic vessel
  9. Watershed
    (between the cervical and axillary lymph nodes
    and above the navel))

B - catchment areas of the lymph nodes
a - on the neck
b - in the armpit area
c - in the groin area
You can find an overview of all images from Dr-Gumpert under: medical images

Figure lymph nodes: lymphatic system (A) and lymph nodes in the neck and head area (B)

Lymphatic system

  1. Head lymph nodes -
    Nodi lymphoidei capitis
  2. Cervical lymph nodes -
    Nodi lymphoidei cervicales
  3. Mouth of the breast duct
    in the left arm-head vein -
    Thoracic duct
    Left brachiocephalic vein
  4. Mouth of the right main
    lymph duct in the right
    Arm head vein -
    Dexter lymphatic duct
    Vena brachiocephalica dextra
  5. Superior vena cava -
    Superior vena cava
  6. Axillary lymph nodes -
    Nodi lymphoidei axillares
  7. Milk breast duct -
    Thoracic duct
  8. Lymphatic vessels -
    Vasa lymphatica
  9. Abdominal lymph nodes -
    Nodi lymphoidei abdominis
  10. Pelvic lymph nodes -
    Nodi lymphoidei pelvis
  11. Inguinal lymph nodes -
    Nodi lymphoidei inguinales
  12. Mandibular lymph nodes -
    Nodi lymphoidei submandibulares
  13. Anterior cervical lymph nodes -
    Nodi lymphoidei cervicales anteriores
  14. Superficial lateral cervical lymph nodes -
    Nodi lymphoidei cervicales
    lateral superficiales
  15. Deep lateral cervical lymph nodes -
    Nodi lymphoidei cervicales
    lateral profundi
  16. Mastoid lymph nodes -
    Nodi lymphoidei mastoidei
  17. Occipital lymph nodes -
    Nodi lymphoidei occipitales
  18. Facial lymph nodes -
    Nodi lymphoidei faciales
  19. Parotid lymph nodes -
    Nodi lymphoidei parotidei

You can find an overview of all images from Dr-Gumpert under: medical images

Histology / tissue of the lymph nodes

The microscopic structure of a lymph node has three layers and is divided into the outer cortex (cortex), the middle paracortical zone (paracortex) and the inner marrow.

The whole thing is surrounded by the connective tissue capsule, from which branches (trabeculae) extend into the interior of the lymph node.

The layers of the lymph node are penetrated by the lymph sinuses. These are spaces in which the lymph takes its way inside the lymph node until it leaves the lymph node again at the hilus.

Depending on the location, a distinction is made between the marginal sinus located directly under the capsule, the intermediate sinus running through the cortex and paracortex, and the medullary sinus located in the medulla. The supplying lymphatic vessels flow into the marginal sinus and the vas efferens emerges from the medullary sinus.

Furthermore, depending on the layer, different cells can be found in the lymph node tissue. In the cortex, there are B-lymphocytes, a type of white blood cell, in rounded clusters (follicles).
Another type of white blood cell called T lymphocytes is found in the paracortical zone. Finally, activated B-lymphocytes and phagocytes of the body, so-called macrophages, are found in the marrow.

Function of the lymph nodes

The lymph nodes fulfill several functions. On the one hand, they serve to activate, multiply and store defense cells, the B and T lymphocytes.

In addition, the cells contained produce antibodies after activation by germs contained in the lymph, which are then released into the bloodstream in order to fight the pathogens.

The lymph nodes also act as filters for the lymph fluid, that is, they free them from:

  • Pathogens
  • Foreign bodies (e.g. soot particles) or
  • Tumor cells.

Read more on this topic:

  • What are B lymphocytes?
  • Lymphatic system

Diseases of the lymph nodes

Lymph nodes can change in their catchment area when there is inflammation. Sometimes they swell painfully and can be felt through the skin from the outside.
Examples of such inflammatory changes are Respiratory infectionsin which the cervical lymph nodes can enlarge. Even after being infected with the HIV (AIDS) or the EBV virus (Glandular Pfeiffer feverOne of the first symptoms at the onset of the disease is mononucleosis), the lymph nodes may swell.

There are also tumor diseases that affect lymph nodes. Often one finds daughter tumors (metastases) of another tumor in the body if the cancer cells washed up from there via the lymph cannot be eliminated, but settle and multiply.

More rarely, cancer develops directly in the lymph node. In such cases one speaks of a Lymphoma, in which Hodgkin lymphoma from Non-Hodgkin lymphoma can be distinguished.

Lymph nodes swollen

Lymph nodes can swell for various reasons - the body generally has a defense reaction. When the body has to fight off invading pathogens, the immune system is activated. The body's important filter stations and immune cells that can migrate out of the lymph nodes are located in the lymph nodes.In the lymph fluid, pollutants and pathogens are flushed into the lymph nodes, where a defense reaction can then be initiated. In this context, the lymph nodes then swell. This can be quite painful as the lymph nodes can enlarge significantly in a very short time in the event of an acute infection. Medically, a lymph node swelling is also known as lymphadenopathy or lymphadenitis. However, the lymph nodes can also swell with other diseases, for example with malignant diseases. The increase in size of the lymph nodes is more often due to the migration of degenerate cells into the lymph nodes. There the malignant cells then continue to divide and form a lymph node metastasis of the primary tumor. In the context of breast cancer, for example, the lymph nodes in the armpits can become swollen as the tumor has spread.

Read more on the topic:

  • Lymph node involvement in breast cancer
  • Lymph nodes swollen

Lymph node pain

Painful lymph nodes are generally more of a good sign and more likely to indicate one benign cause the lymph node enlargement. When infected, the lymph nodes react to pathogens and enlarge. Since the surrounding tissue is not used to the rapid enlargement, nerve fibers and other surrounding structures are stretched, which Pain can cause. Sometimes the rapidly swollen lymph nodes also show reddening of the skin. In contrast, malignant lymph node enlargements often grow slowly and over a long period of time, so that the surrounding tissue has enough time to make room and is only slowly stretched. For this reason, malignant lymph nodes are less painful than benign lymph nodes.

Lymph node cancer

Cancers can spread to the lymph nodes. In the early stages of the disease, only a circumscribed area is affected. However, over time as the cancer continues to grow, it may connect to lymphatic vessels and surrounding structures. It can grow into neighboring organs, but it can also affect lymph nodes. Tumor cells can be flushed into the lymph nodes via the lymphatic system. The first lymph node to receive lymph fluid from a region of the body is also known as the sentinel lymph node. If cancer is diagnosed, a targeted search is made for the sentinel lymph node. If this is tumor-free, it can be assumed that the other lymph nodes do not contain any tumor cells either. However, if the sentinel lymph node is already affected by the tumor, it must be removed and / or irradiated together with other lymph nodes in the corresponding body region, depending on the therapy concept. The settlements of the tumor in the lymph nodes are also known as lymph node metastases. Affected lymph nodes continue to enlarge and often feel bumpy, irregular and rough. Often they are fused with the environment and can therefore no longer be moved in the tissue, as is normally the case. Usually, pressure on malignant lymph nodes does not cause any pain. In the case of enlarged lymph nodes caused by inflammation, however, pressure on these lymph nodes can usually trigger pain.

You can find further information under our topic: Sentinel lymph nodes

Lymph node regions

Lymph nodes on the groin

Lymph nodes are spread all over the body in humans. There is also an important lymph node station in the groin. The inguinal lymph nodes take the lymph fluid from the lower extremity and the Organs of the pelvis on. They are therefore a crucial drainage station. The best way to feel the lymph nodes in the groin is to look for the pulse of the Femoral artery (Arteria femoralis), which can also be felt in the groin. There are usually groups of lymph nodes around the artery. The groin lymph nodes are palpable in most adults because they are often larger than other lymph nodes. From childhood falls, open knees and other injuries to the lower extremities, the lymph nodes are often stressed from childhood. The frequent activations lead to an increase in connective tissue in the lymph nodes, which is why they then remain slightly enlarged and palpable without this having any pathological significance.

Of course, the lymph nodes in the groin can also be enlarged in malignant diseases, for example prostate cancer in men, uterine or ovarian cancer in women or colon cancer when the cancer cells have spread to the lymph nodes. Any other malignant disease can spread to the lymph nodes at an advanced stage and then also affect the inguinal lymph nodes. Benign swellings of the lymph nodes in the groin are expressed as enlarged, but soft and movable lumps that can be tender on pressure. As part of a infection however, enlarged lymph nodes usually swell within a few weeks. Constant increase in the size of a lymph node in the groin is therefore rather suspicious of a malignant finding.

Lymph nodes on the neck

Most of the lymph nodes in the human body are located in the Neck region. They are particularly common in the context of Colds swollen and then often prepare Pain. The lymph nodes on the neck are arranged in different lines. A line runs in neck (nuchal lymph nodes), one begins in front of the Ears (pre-auricular lymph nodes) and runs on the front edge of the large neck muscle towards the clavicle, a line begins behind the ears and runs on the rear edge of the neck muscle towards the clavicle (retro-auricular lymph nodes). There are also lymph nodes in the Jaw angle and in the soft tissues under the lower jaw to the chin (submandibular and submental lymph nodes). With colds, these lymph nodes are often swollen and tend to be tender. Once the cold or sore throat is over, the lymph nodes swell quickly. If it happened very often Inflammation however, the cervical lymph nodes can remain slightly enlarged over the long term. In the context of malignant diseases, cervical lymph nodes can also enlarge if the cancer in question has spread to the lymph nodes. The lymph nodes then feel more roughly, irregularly and are caked with the environment. The lymph nodes are then seldom painful. In the case of malignant diseases in the head and neck area, the cervical lymph nodes are particularly often affected due to their anatomical proximity. This can be the case for example Larynx, tongue, tonsil, salivary gland or esophagus tumors be the case. However, any other cancer can also settle in the lymph nodes. A tumor that develops directly in the lymph nodes is Hodgkin's lymphoma. It is not uncommon for it to manifest itself in cervical or axillary lymph nodes and is usually treated with chemotherapy.

Lymph nodes on the neck

There are also lymph nodes in the neck. These are also known medically as nuchal lymph nodes. They can be enlarged with infection, inflammation or malignant diseases. As with the cervical lymph nodes, the lymph nodes in the neck are particularly important Coldsaffecting the upper respiratory tract, as well as swollen with a sore throat. Malignant diseases of the head and neck area can occur in the lymph nodes of the neck Metastases form.