The lymphatic system is an important part of the immune system. The finely branched network runs parallel to the blood vessels like a canal system. It removes excess substances and at the same time filters out pathogens and foreign particles. This is why the lymph nodes swell in some diseases.
Here you will find further information and selected doctors for diseases of the lymphatic system.
The word lymph comes from the Latin "lympha", which means "clear water". In fact, lymph is a watery, yellowish-colored substance. It flows through the entire body in meter-long, very fine channels.
Lymph is formed from nutrient-rich blood plasma. When it passes from the arterial to the venous blood vessels, around 10 percent of the blood plasma remains in the intercellular spaces. That is about two liters per day. These remnants are referred to as tissue fluid.
Wafer-thin lymphatic capillaries begin everywhere in the intercellular spaces of the body. They absorb the tissue fluid that remains there and transport it further towards the heart as lymph. There it is reunited with the blood in the superior vena cava.
The initially very branched lymphatic capillaries merge to form larger lymphatic vessels. These usually run parallel to the venous blood vessels. Parts of these vessels, the so-called lymphatic hearts, contract about ten times a minute through muscle contraction. In this way, they provide the necessary pumping movement.
The lymphatic system runs through the entire body. A lymph node is also shown here © lom123 | AdobeStock
In certain places, for example
the lymph vessels are interrupted in the form of nodes. Here the lymph from
to protect the organism from damage.
The lymph nodes, which are around 1-20 mm in size, are lymphatic organs. They contain lymphocytes and macrophages. These are special immune cells belonging to the white blood cells that recognize and attack viruses and bacteria.
The lymph nodes in the neck can become palpable during a viral flu, for example. This is because the infection causes them to increase their output and swell accordingly.
Embedding of lymphatic capillaries (green) between the blood vessels © ilusmedical | AdobeStock
In addition to the lymph nodes, the system also includes other lymphatic organs. Lymphocytes can multiply or differentiate in these organs. They complement each other in their functions:
This is where it all begins. Lymphopoiesis takes place in the bone marrow, where lymphocyte stem cells first develop into lymphoblasts. These in turn give rise to two types of lymphocyte precursors:
They pass through the bone marrow and then settle in the various other lymphatic organs.
In the thymus, the pro-T lymphocytes coming from the bone marrow are transformed into T lymphocytes.
They first undergo selection and then imprinting, which prepares them for their important role in the immune system.
Among other things, the spleen produces the aforementioned macrophages (also known as defense or scavenger cells ). It also stores lymphocytes and breaks down outdated blood cells.
The lymphatic ring consists of the tonsils in the throat, tongue and palate. It destroys pathogens that want to spread in the body from the air we breathe and via the mucous membranes.
B lymphocytes also multiply in the tonsils.
Peyer's plaques are also known as Peyer's patches or Peyer's glands. They are found in the mucous membrane of the small intestine up to the appendix.
They consist of an accumulation of microscopically small colonies of B lymphocytes, so-called lymphoid follicles. They make an important contribution to the intestinal defense against infection and transmit immunological information.
If the lymph flow is disturbed or interrupted, this leads to increased fluid accumulation in the tissue. Such lymphoedema usually occurs in the extremities.
The affected body region swells and the subcutaneous fatty tissue develops a doughy consistency. If left untreated, this can lead to
with corresponding functional impairment.
The only remedy here is regular manual lymphatic drainage. A masseur stimulates the vascular system with light, circular movements. This allows the lymph to drain better.
Inflammation of lymph vessels usually occurs in one of the superficial lymphatic vessels. In the affected region, the skin reddens and a red cord spreads from the focus of inflammation towards the center of the body. The area is usually painful and slightly swollen.
If lymphangitis is caused by bacteria, it can be treated with antibiotics. See a doctor in good time! Otherwise it can lead to complications, in the worst case even to blood poisoning (sepsis).
In addition to viruses and bacteria, lymph nodes also filter out tumor cells in the event of cancer. These accumulate in the node and then gradually spread throughout the body via the lymphatic system.
To prevent this, the doctor can remove individual lymph nodes located near a tumor.
Other cancers such as
directly affect the lymphatic system. In malignant lymphomas, the lymph nodes typically swell. They occur in different forms and are treatable to varying degrees.
In breast cancer, the lymph nodes in the armpits swell (so-called sentinel lymph nodes) © Henrie | AdobeStock
Swollen lymph nodes are a serious sign of illness, but no reason to panic. They often occur with common colds or also with mononucleosis.
See a doctor if
