What Is Acquired Immunodeficiency Syndrome?

Acquired immunity is the acquired defense function that the human body gradually builds up after birth. It is characterized by being born after birth and only acts against a specific pathogen or foreign body.

The first line of defense is

1. Physiological defense means that the human body resists the invasion of pathogens and their toxic products to protect people from infectious diseases.

Second, it is self-stabilizing. Human tissue cells are constantly being metabolized, and there are a large number of new cells at any time to replace aging and damaged cells. The immune system can recognize aging and dead cells in time and remove it from the body to maintain the stability of the body.

3. Immune surveillance, which mainly monitors the cells that have mutations, identifies them in time, and eliminates them.

4. Immune tolerance. Under normal conditions, the immune system does not produce an immune response to antigens expressed by its own tissue cells and does not cause autoimmune diseases. On the other hand, antigens expressed by foreign pathogens and harmful molecular molecules produce immune responses and are eliminated In terms of this layer of function, the immune system has the function of "differentiating between self and non-self".

Vaccination uses antigens to stimulate the body to produce antibodies and improve the body's resistance.

Can be roughly divided into two types of specific immunity and non-specific immunity, the two are closely related. Non-specific immunity is an immune function that is formed by organisms in the course of germline development in the continuous struggle with pathogenic microorganisms and can be passed on to offspring. It is closely related to the tissue structure and physiological functions of the human body. Specific immunity is the immune function obtained by the body after being stimulated by internal and external environmental factors in the day after tomorrow. It can recognize the same antigens that come into contact again and respond accordingly. It requires the participation of highly differentiated tissues and cells to complete.

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1. Naturally immune. When a person has some kind of infectious disease, he will not get a second time when he is cured. This immunity is acquired the day after tomorrow because it is naturally infected with a certain pathogenic microorganism, and the body automatically produces it after healing;

2. Artificial autoimmunity. Infection of humans with a very toxic pathogenic microorganism by artificial methods, such as inoculation with BCG, people automatically gain resistance to certain diseases such as tuberculosis

3 Natural passive immunity. The immunity that a baby receives from the mother. The baby's immune system has not yet developed in six months, but he rarely gets sick. Because the fetal blood circulation is connected to the mother, the mother's resistance is injected into the fetus through the blood.

4 Artificial passive immunity. Immunoglobulin and other injections are given to patients to obtain relevant immunity immediately.

Specific immunity has specificity, can resist repeated infection by the same microorganism, and cannot be inherited. Divided into two types of cellular immunity and humoral immunity.