C11: immunity in Humans

• neutralisation • agglutination • precipitation • opsonisation • lysis

• histamine is secreted in the infected area • stimulate the immediate inflammatory response • blood capillary expand to allow more blood to flow to the infected area • increase the permeability of blood capillaries to phagocytes • cause accumulation of clotting factor and phagocytes in the infected area • blood clotting mechanism is triggered • phagocyte carry out phagocytosis

• tough and difficult to penetrate • continuous shedding of dead tissue prevent growth of bacteria • secrete sebum that contain oil and acid • secrete sweat the contain lysozyme to break down cell wall of bacteria

• immune response of lymphocyte • large amount of lymphocyte accumulate in lymph node • to produce specific antibodies to destroy specific antigen and foreign particles • cause lymph node to swell • T lymphocyte and B lymphocyte • T lymphocyte attack cells infected by pathogen • and stimulate B lymphocyte to produce memory cell • if the same pathogen attacks, the memory cells will stimulate production of antibodies immediately • lymph node also contain macrophage that destroy pathogen, dead tissue and foreign particles through phagocytosis

• fragments of dead tissue • microorganisms • red blood cells