Introduction to immunization

Directory 1 pinyin 2 English reference 3 notes 1 pinyin mimnyy.

2 English reference immunity

According to the traditional concept of immunity, immunity means that the body no longer feels the re-invasion of pathogens. For example, people will not get smallpox and measles for the second time, which is anti-infection immunity. With the continuous development of immunology, the research on immunity has gone far beyond the scope of anti-infection immunity. According to the concept of modern immunity, immunity is the physiological function of the body to recognize and exclude antigen foreign bodies, and it is a protective physiological response of the body. Its function is to identify "self" and "non-self" and eliminate antigenic foreign bodies, thus maintaining the relative stability of the body's physiological functions. The result of immune reaction is beneficial to the body under normal circumstances, but in some cases or for a few people, it may also cause immunopathological reaction.

Immunity can be divided into nonspecific immunity and specific immunity. Nonspecific immunity means that it has a certain degree of resistance to all pathogenic microorganisms and has no special selectivity. Also known as innate immunity or innate immunity. Such as the barrier function of skin and mucosa, the barrier function of blood-brain barrier and placenta; Phagocytosis of phagocytes (neutrophils in blood and macrophages in tissues) and sterilization of bactericidal substances (lysozyme, etc.). ). Specific immunity refers to the body's specific resistance to a microorganism or its products, including humoral immunity and cellular immunity.

Humoral immunity mainly refers to the immune process of producing antibodies through B lymphocytes. For example, bacterial exotoxin entering the body loses its toxicity after combining with antitoxin (an antibody) in the body. After the virus invades the human body, the antibody binds to the antigen (virus), so that the virus loses its vitality and cannot invade human cells. The process of humoral immunity can be roughly divided into three stages: induction stage, reaction stage and effect stage. The induction stage means that the antigen invades the human body and is swallowed by macrophages, and then the antigenic determinant is transmitted to T lymphocytes, and then transmitted to B lymphocytes through T lymphocytes. The reaction stage means that B lymphocytes are activated to form effector B lymphocytes, a small part of which are transformed into memory cells, and most effector B lymphocytes proliferate rapidly, producing a large number of effector B lymphocytes and a large number of antibodies. The process in which antibodies produced by effector B lymphocytes combine with antigens to produce an immune response.

Cellular immunity mainly refers to the immune reaction process that exerts immune function through T lymphocytes, and it is also divided into three stages like humoral immunity process. The induction stage is basically the same as humoral immunity. The reaction stage means that T lymphocytes receive antigen * * * and form effector T cells, some of which are transformed into memory T cells, and most of them rapidly proliferate to form a large number of effector T cells, resulting in a stronger specific immune response. Effective period refers to the close contact between effector T cells and host cells (target cells) invaded by antigens, which activates lysosomes in target cells, changes membrane permeability and osmotic pressure of target cells, and finally leads to the death of a cell. When the immune function is normal, it plays an immune protection role in the body. When the immune function is out of balance, it can cause allergic reactions (such as pollen allergy and penicillin allergy) and autoimmune diseases (such as rheumatic heart disease and rheumatoid arthritis). Systemic lupus erythematosus and so on. ) or immune deficiency diseases (such as AIDS), damaging health.