第七 单元 免疫、变态反应、结缔组织病（Seventh unit immunity, allergy, connective tissue disease）.docVIP

第七 单元 免疫、变态反应、结缔组织病（Seventh unit immunity, allergy, connective tissue disease） Unit seventh, immunity, allergy, connective tissue disease.Txt you can not make everyone satisfied, because not all people are people, successful people are in a way cattle B, road erection do you think I will watch you die? I will close my eyes with the seventh unit of immunity, allergy, connective tissue disease Section 1 Characteristics of pediatric immune system Specific cellular immunity (T cell immunity) (I) thymus: thymus is the central immune organ, and lymphoid stem cells differentiate into mature T cells (CD3 positive, CD4 or CD8 single positive) sites. (two) T cells: the function of CD4+T cells is to modulate immune responses, called helper T cells (TH). CD8+ cells function as cytotoxic antigens, termed cytotoxic T cells. (three) cytokines: a variety of cytokines can be produced in the process of immune response. TH1 cells secrete interferon gamma, interleukin -2, and TH2 cells secrete interleukin -4, 5, 6, 8, and 9. Two, specific humoral immunity (B cell immunity) (1) bone marrow and lymph nodes: the bone marrow is the mature site of B cells and functions as a capsule. (two) B cells: compared with T cell immunity, B cells develop slowly. (three) immunoglobulin: the immunoglobulin with antibody activity is called immunoglobulin. 1.IgG: through the placenta, there are four subclasses, with the highest proportion of IgG1. IgG1 targets protein antigens, antibodies, and IgG2 against polysaccharide antigen antibodies, and IgG4 is associated with allergies. 2.IgM: not through the placenta, IgM high at birth, need to further detect specific antibodies, clear whether the presence of intrauterine infection. Early adult level. 3.lgA: high lgA in cord blood suggests intrauterine infection and local anti infection of secretory lgA mucosa. 4.lgD (5 years of age, adult 20%) and lgE (7 years of age) are difficult to pass through the placenta. Three 、 nonspecific immunity Phagocytosis: large m