When our nose runs or a cut in our finger throbs noticeably, our immune system is at work. Even if we perceive this as unpleasant and annoying: They are the symptoms of a process running in the background that prevents much worse. This is because our body's own defenses prevent us from becoming seriously ill or even poisoned by a cut on our finger; and when we have a cold, our nose runs because it removes pathogens from the body in this way. A highly complex system developed over millions of years is at work here - even if it expresses itself in the form of "snot and water".
The tasks of the immune system
The task of our immune system is to keep damage away from the body. This affects the tissues and organs, of course, but also our psyche. As early as the 1970s, it was proven that emotions also affect the physical immune system via the nervous system. Current research also proves the reverse: disturbances of the immune system can trigger psychological problems. "In a healthy body dwells a healthy mind" - this many centuries old proverb receives new confirmation on this path.
The dual immune system
Actually, there are two immune systems: The innate and the acquired. An innate immune system is inherent to all living organisms, including plants or bacteria. The acquired (also: learned or adaptive) immune system occurs only in more highly developed life forms. It is adaptive and allows the body to respond to new stimuli.
The innate immune response
All living things are equipped with certain protective mechanisms from the moment they are created, such as a skin that prevents pathogens from entering. This is the innate immune system. It is also called the "nonspecific immune system" because it responds to every stimulus with the same reaction.
An example of such a standard response in humans is inflammation: it helps fight off pathogens just as it helps heal a bruise. The familiar symptoms of inflammation, such as redness, swelling, warmth and tenderness, are due to the fact that helper and defense cells, as well as fluid, are sent to the damaged tissue by the non-specific immune system to enable the removal of destroyed cells and the building of new structures. Whether this is the result of an accident or an attack by bacteria, the innate immune system does not care.
The learned immune response
The acquired immune system develops throughout life in response to external stimuli. It enables the body to respond to disease, to produce defense cells, and thus to develop immunity to certain pathogens. This is why, for example, you usually only get chickenpox once in your life. Vaccinations also function according to this principle. However, the adaptive immune system has limits: It can "forget" pathogens over the course of a lifetime, especially if they have been given in attenuated or "dead" form, as in vaccinations. For this reason, some vaccinations need to be refreshed from time to time.
What is the composition of the immune system?
The immune system consists of a number of defense mechanisms. These include physical barriers such as the skin, as well as certain organs, the immune cells they produce, and the transport pathways they need to perform their tasks.
Physical barriers
The most obvious boundary is the skin, which prevents contaminants from entering the body. Sweat and sebum make it difficult for pathogens to settle on it. These literally stick to mucous membranes and can be transported away - for example, by the nasal hairs or the cilia in the lungs. Stomach acid also represents a barrier for microorganisms. Our entire body is permeated with protective and defense mechanisms - all of which are already part of the immune system.
Cells and organs
The spleen, appendix, bone marrow and many other sites in the body produce immune cells on demand or in reserve. These defense cells perform various complex tasks: Certain cells, for example, cling to invading pathogens and mark them in this way so that other cells can destroy or dispose of them. Cells that belong to the specific part of the immune system produce antibodies themselves against novel threats. They have previously learned how these are structured and can be combated from phagocytes, which have devoured the invaders. The disposal of the repelled attackers takes place, among other things, via the lymphatic system, which runs through the entire body and serves exclusively as a transport route for the immune system.
Strengthening the immune system
A healthy immune system depends on an adequate supply of the right nutrients. But other factors also play a role in the smooth functioning of the immune system.
Nutrition
A balanced diet is the be-all and end-all for a healthy immune system. Above all, it is important to have an adequate supply of vitamins and minerals - so fruit and vegetables should definitely be on the menu. Iron, zinc, selenium and iodine are important minerals for the immune system and are contained in various foods. You should also drink plenty of fluids, as this helps to eliminate harmful substances.
Exercise
Regular exercise strengthens the immune system. The entire metabolism is stimulated, and nutrients are transported through the body. Sufficient and persistent, these are the key words - exaggerated maximum performance should not be the goal, but can even do harm. Gentle" endurance sports are considered particularly suitable: cycling, jogging, hiking, swimming.
Sun
Sunlight enables the body to produce vitamin D. In addition to many other tasks, vitamin D also fulfills an important function for the immune system. Certain defense cells on the skin are stimulated by vitamin D to produce antibacterial substances and thus prevent the penetration of pathogens.
Relaxation and joie de vivre
The interplay between the immune system and the psyche is a relatively new field of research. Currently, the main question is whether the immune system can influence the psyche, i.e. whether, for example, a weak immune system promotes depression.
On the other hand, it has been widely studied and proven that emotions can weaken or strengthen the immune system. Permanent stress weakens the immune system - relaxation has been proven to be an effective way to support the immune system. Optimism can support healing processes and strengthen pathogen defenses. The role of social ties has also been proven: People with a good social network have been shown to have more immune cells in their bodies.
So if you want to do something really good for your immune system, take a walk with friends and family for a good, varied meal and then lie down in the hammock. What doesn't one do for one's health!