11 Human health physiology 2

Describe the process of clotting. 1) Platelets and damaged cells release clotting factors. 2) Prothrombin  thrombin 3) Fibrinogen  fibrin, which captures red blood cells.

Outline the principle of challenge and response, clonal selection and memory cells as the basis of immunity.

Define active immunity, passive immunity, natural immunity and artificial immunity. Active immunity- immunity due to the production of antibodies by the organism itself after the body’s defense mechanisms have been stimulated by invasion of foreign microorganisms. Passive immunity- immunity due to the acquisition of antibodies from another organism in which active immunity has been stimulated, including via placenta or in the colostrum. Natural immunity- immunity due to infection. Artificial immunity- immunity due to innoculation.

Explain antibody production. 1) Macrophage presents antigen to helper T cell 2) Helper T cell activates B cell 3) B cells divide to form clones of plasma cells and memory cells, which secrete antibodies. Plasma cells- fight the pathogen immediately. Memory cells- stay in body, armed and ready if the pathogen appears in again in the future.

Describe the production of monoclonal antibodies, and include one use in diagnosis and one use in treatment. Monoclonal antibodies are produced by fusing cancerous tumor cells with B-cell. This hybrid cell then proliferates and produces antibodies in perpetuity. Diagnosis- used to detect HIV in the blood stream, as well as HCG in pregnancy tests. Treatment- emergency treatment of rabies, blood and tissue typing for transplants.

Outline the principle of vaccination. A vaccine introduces the disabled pathogen in some for to the body, stimulating an immune response. Memory cells are created and circulate in the body, in case the real pathogen ever shows up.