What are the two ways in which the body acquires autoimmunity?

The body's immune system is composed of three parts: immune organs, immune cells and immune-active substances. Immune organs are composed of immune cells, which are the places where immune cells are generated and matured, including bone marrow, lymph nodes, spleen, thymus, etc. Immune cells are cells with immune functions, such as lymphocytes, phagocytic cells, etc. Immunoactive substances are substances produced by immune cells and other cells that exert immune effects, including antibodies, lysozyme, lymphokines, and so on.

Generally, the human immune system can clear viruses, but some viruses are very "smart", and the human body cannot recognize them and even prepare beneficial substances, and the immune system will attack the La. The most typical is HIV, which reverses itself and dresses itself up as a substance that is not harmful to the body, thus evading the attack of the immune system. In another case, the virus invades the human body and causes complications, or aggravates the pre-existing underlying disease, so that before the immune system can remove the virus, the complication or pre-existing underlying disease causes the person's organs to fail and die.

Finally, if someone's immunity is too high (the immune system is too active) and the immune system mobilizes too many inflammatory mediators to attack the virus, an inflammatory storm will be generated, and the patient will die not from the virus but from their own inflammatory response.

Supplement: The body's immune system can mainly eliminate most viruses, but only very slight bacteria, too many bacteria or some bacteria The immune system is powerless, and can only rely on antibiotics to kill bacteria. In addition, the immune system itself also creates diseases, such as rheumatism, rheumatoid, and many allergies.

The third course. The first line of defense is composed of ** and mucous membranes, which can not only block pathogens from entering the human body, but also their secretions (such as lactic acid, fatty acids, stomach acid and enzymes, etc.) have a bactericidal effect.

The second line of defense is the bactericidal substances in body fluids – lysozyme and phagocytes.

The first two lines of defense are the natural defense functions gradually established by human beings in the process of evolution, which are characterized by the fact that all people are born with them, and they do not target a specific pathogen, but have a defensive effect against a variety of pathogens, so they are called non-specific immunity (also known as innate immunity).

The third line of defense is mainly composed of immune organs (tonsils, lymph nodes, thymus, bone marrow, spleen, etc.) and immune cells (lymphocytes, phagocytic cells, etc.) with the help of blood circulation and lymphatic circulation. The third line of defense is the acquired defense function gradually established by the human body after birth, which is characterized by being produced after birth and only acts against a specific pathogen or foreign body, so it is called specific immunity (also known as acquired immunity).

1. Defense.

The most basic function of the immune system is the ability to resist and eliminate various microorganisms, so that the human body will not be invaded and infected by pathogens. In other words, resistance is the most basic function of immunity.

2. Self-stability.

Not being invaded and infected by external pathogens is an important condition for the body to maintain a stable internal environment. For example, the spleen, which has many immune cells with strong phagocytic functions, can "detect" red blood cells in the blood and maintain blood vitality by removing old and malfunctioning red blood cells through phagocytosis. With the increase of age and the aging of the body, the body's immune self-stability will continue to decline, which is also an important reason for the frequent occurrence of vascular diseases in middle-aged and elderly people.

3. Surveillance.

Everyone is constantly producing tumor cells and being infected by various viruses, but not everyone will suffer from tumor diseases or viral infections, because the immune system can eliminate these "bad molecules" through immune surveillance mechanisms such as NK cells, so as to protect the body from the threat of tumor and viral infection.

4. Recognition.

Well-bodied ** equipment can't be fought when you see people, and it is very important to identify friends and foes. The body's immune system has the ability to recognize its own and foreign antigens, develop tolerance to its own antigens, and reject foreign antigens.

Correct immune recognition is the beginning of the correct functioning of the immune system. However, in some cases, if there is an error in immune identification, it can lead to immune dehydration dysfunction and cause immunopathological damage. Rheumatoid arthritis, for example, is caused by this mechanism.

5. Activating force.

When the immune system recognizes friend or foe, T lymphocytes and B lymphocytes activate, proliferate, and differentiate, and then produce immune response products such as antibodies or sensitized lymphocytes. The aging of immune cell function in the elderly will lead to a decrease in immune activation, and after infection with pathogens, the specific immune activation rate is slower, and serious pathogen infections are more likely to occur.

6. Effect.

Response products such as antibodies produced by immune responses are the main products of the body's elimination of pathogens. For example, when the hepatitis B virus infects the human body, the body produces a variety of antibodies, but only antibodies against the hepatitis B virus surface antigen can prevent the hepatitis B virus from infecting liver cells.

7. Adjusting force.

Kill 1,000 enemies and lose 800 yourself, this deal is not a failure and is cost-effective. This requires the body's immune system to be well regulated. While eliminating pathogens, it avoids immunopathological damage and adverse reactions of immune responses such as fever.

If the body's immune regulation ability is abnormal, it is very scary, and it will die in a serious way, and it will kill itself.

The immune system is a defense network that covers the whole body. The first line of defense to protect the body is **. Cell membrane.

Respiratory tract. Gastrointestinal tract. Urethra and kidneys.

However, the barrier and filtration mechanisms alone do not fully protect us, and the body relies on the blood cells and proteins that make up the immune system to act as a defense.

The immune BAI system is composed of immune organs, immune cells and anti-epidemic active substances.

dao。Immune organ: The place where immune cells are generated, matured, or centrally distributed, including bone marrow, thymus, spleen, lymph nodes, etc.

Immune cells (cells that exert immune functions): 1Phagocytic cells 2Lymphocytes origin: hematopoietic stem cells in the bone marrow T cells (mature in the thymus) B cells (mature in the bone marrow).

Immunoactive substances: substances produced by immune cells or other cells that exert immune effects, including antibodies, lymphokines, lysozyme, etc.