Functions of the immune system

The immune system of our body is very powerful. It is also our body's defense system, which can effectively defend against the invasion of some diseases. This system is composed of many immune organs, including lymph, spleen, tonsils, appendix, etc., as well as immune cells. The immune system has many functions, defense, cleaning, and monitoring are common functions that enable our body to function normally.

The immune system plays a very important role for us. It can help us resist some viruses from the outside world and keep our bodies from getting sick. For children, the immune system can develop safely. The body's immunity is still very low, but it will gradually get better in the future.

Basic Functions

1. Identify and eliminate foreign invading antigens, such as pathogenic microorganisms. This function of preventing the invasion of external pathogens and eliminating invaded pathogens and other harmful substances is called immune defense.

2. Identify and eliminate mutated tumor cells, senescent cells, dead cells or other harmful components in the body. This function of detecting and eliminating "non-self" components in the body at any time is called immune surveillance.

3. Maintain the stability of the internal environment of the immune system through autoimmune tolerance and immune regulation.

Immune organs

Central immune organs

marrow:

The bone marrow is located in the medullary cavity and is divided into red bone marrow and yellow bone marrow. Red bone marrow has active hematopoietic function. Therefore, the bone marrow is the place where various blood cells and immune cells occur and mature, and is an important central immune organ of the human body. Its functions are as follows:

1. The place where various blood cells and immune cells occur;

2. The site where B cells differentiate and mature;

3. The place where the humoral immune response occurs.

Thymus:

Behind the bones and above the heart is the place where T cells differentiate, develop and mature. The size and structure of the human thymus vary significantly with age. The thymus matures at 20 weeks of embryonic development and is the earliest immune organ to develop. At birth, the thymus weighs about 15-20g, and then gradually increases in size, reaching 30-40g by puberty. After puberty, the thymus gradually atrophies and degenerates with age, and is basically replaced by adipose tissue in old age. As the thymus gradually atrophies and its function declines, cellular immunity decreases, and the surveillance function for infection and tumors is reduced. The thymus has the following 3 functions:

1. The place where T cells differentiate and mature;

2.Immunomodulation: It has a regulatory effect on peripheral immune organs and immune cells;

3. Establishment and maintenance of autoimmune tolerance.

Peripheral immune organs

spleen:

The spleen is a hematopoietic organ in the embryonic period. After the bone marrow begins to produce blood, the spleen evolves into the largest peripheral immune organ in the human body. It has 4 functions:

1. The place where T cells and B cells reside;

2. The site where the immune response occurs;

3.Synthesis of certain biologically active substances;

4. Filtering effect.

Lymph nodes:

There are 500 to 600 lymph nodes in the human body. They are peripheral immune organs with complete structures and are widely present in the lymphatic channels in non-mucosal parts of the body. Lymph nodes have the following functions:

1. The place where T cells and B cells settle;

2. The site where the immune response occurs;

3. Participate in lymphocyte recirculation;

4. Filtering effect.

Everyone should understand the function of the immune system. Our body can function normally and not get sick, which all depends on the immune system. We all know that children’s immune systems are not well developed, so they will get sick very easily. We should pay attention to developing good habits, enhancing the body’s resistance, and try not to get sick.