The two parts of the immune system

Even newborn babies have an active body defense system. This innate immune system fights against pathogens of all kinds that enter the body. There is also the acquired immune system. It develops over time and specifically attacks pathogens that it has previously come into contact with. The acquired immune system mainly develops during childhood, but it continues to learn more and more in later years.

Everyone can do something to ensure that both systems function perfectly. The immune system can be strengthened with simple tips such as a balanced diet rich in vitamins, plenty of exercise and not smoking.

How does the innate immune system work?

Our body's defenses consist of several important components right from the start of life:

• Protective barriers: The skin and mucous membranes prevent bacteria, viruses or fungi from entering the body unhindered. They are lined with a protective acid mantle that makes it difficult for pathogens to colonize. Other helpers are good bacteria that colonize the skin. As a rule, they do not harm our organism, but they keep the places occupied so that no foreign germs can spread.2
• Defense cells: White blood cells, technically known as leukocytes, patrol the blood and keep an eye out for foreign particles. When they detect something, they release signaling substances into the environment that attract other immune cells. Ultimately, the intruder is destroyed by so-called phagocytes.

But how do the cells of the immune system actually recognize who is foreign and who belongs to the body? Each of the body's own cells actually has a special protein structure on its surface. This acts like an identity card: if the right one is present, the immune cells recognize it as belonging to the body. However, if the cell shows the "wrong" ID, the intruder is unmasked.

How the acquired immune system works

If the innate immune system needs support, the specific or acquired immune defense becomes active. What makes it special is that it can memorize pathogens. As soon as they appear a second time, they are immediately identified and rendered harmless. This is why we only get certain childhood diseases such as measles once in our lifetime. Vaccinations also make use of this system. This allows the organism to get to know certain viruses or bacteria without becoming ill.

Important components of the acquired immune system are

• T cells: Their name is derived from thymus, an organ in which the T cells mature. There are different types of T cells. Some recognize when body cells are infected by viruses, others activate B cells.
• Bcells: They secrete antibodies that are specifically tailored to certain pathogens. They also bind intruders and render them harmless.

Although the acquired immune system reacts more slowly than the innate immune system, it is highly specialized.2 How both immune systems work in detail is complex and still partly the subject of research. Nevertheless, it remains a fascinating system that guards our body around the clock.

When the immune system overreacts

The immune system's tasks are clear: to protect the body from diseases. This does not only include diseases that invade from the outside. There is also a lot to do inside the body: If cancer cells develop, for example, the immune system takes action against them. However, some tumors trick the immune cells so that they remain undisturbed and continue to spread.

In so-called autoimmune diseases, the immune system reacts to the body's own cells, which are actually harmless. This is how diseases such as multiple sclerosis or rheumatism develop. How this faulty reaction of the immune system works is still being researched. The focus is on genetic predisposition, changes in the hormone balance, medication or infections as causes.2

Tips for a healthy immune system

The immune system doesn't need much to perform its tasks without restrictions. Support your immune system with the following recommendations:

• Getenough sleep: the immune system runs at full speed, especially during the deep sleep phase. It is therefore important to get enough sleep.
• Exercise in the fresh air: This improves blood circulation and floods the body with fresh oxygen. This is good for the immune system.
• Drink plenty of fluids: Sufficient fluids keep the mucous membranes moist so that their defense barrier is maintained. The air in the room should not be too dry either - use bowls of water or damp cloths over the radiator to help humidify the air.
• Avoid constant stress: If the body is under long-term stress, this weakens the immune system. Therefore, create islands of relaxation and reduce stress in a targeted manner.

You now know how the immune system works. By adopting a healthy lifestyle, you can ensure that it stays healthy for the rest of your life.

Sources

1 "How does the immune system work?" AOK - Die Gesundheitskasse, https://www.aok.de/pk/magazin/koerper-psyche/immunsystem/wie-funktioniert-das-immunsystem/. Accessed February 14, 2023.

2 "How does the immune system work?" Health Knowledge Foundation, https://www.stiftung-gesundheitswissen.de/gesundes-leben/koerper-wissen/wie-funktioniert-das-immunsystem. Accessed February 14, 2023.

3 "Revitalizing the immune system to fight cancer." Mpg.de, https://www.mpg.de/16602804/0317-moph-belebung-des-immunsystems-zur-krebsabwehr-151445-x. Accessed February 14, 2023.

4 "Autoimmune diseases: Basic info. Health Portal, https://www.gesundheit.gv.at/krankheiten/immunsystem/autoimmunerkrankungen/was-ist-das.html. Accessed February 14, 2023.

5 "Why we need sleep." Techniker Krankenkasse, https://www.tk.de/techniker/magazin/life-balance/besser-schlafen/warum-wir-schlaf-brauchen-2006850. Accessed February 14, 2023.