Immunity
- Created by: LauraNannini
- Created on: 22-04-20 07:32
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- Topic 7
- Phagocytosis
- 1- phagocyte detects chemicals released from the pathogens
- 2- They engulf the pathogen into a vesicle and fuse with the phagosome
- 3- lysosomes also fuse and release lysosome to destroy the pathogen
- 4- Hydrolysed products are then absorbed by the phagocyte
- Phagocytosis is apart of the non-specific immune system response
- Cell mediated response
- Phagocyte engulfs pathogen and presents the antigens from the pathogen on its surface (antigen presenting cell)
- Helper T cells then binds to the phagocyte via receptors
- The TH cells then duplicate
- 1. Memory T cells are created to help fight future infections
- 2. Activates Killer T cells to destroy the specific pathogens
- 3. B lymphocytes are activated and begin to produce antibodies
- 4. Stimulates phagocytosis to enguld pathogens
- The TH cells then duplicate
- Helper T cells then binds to the phagocyte via receptors
- Specific response
- Phagocyte engulfs pathogen and presents the antigens from the pathogen on its surface (antigen presenting cell)
- Humoral response
- B lymphocytes + antigens in blood or tissue fluids
- Antigens enter B cells by endocytosis
- B cell present antigens on its surface (antigen presenting cell)
- Helper T cells bind to the antigens
- B cells activate and undergo mitosis
- Plasma cells to produce antibodies
- Memory T cells to help if a secondary infection occurs
- B cells activate and undergo mitosis
- Helper T cells bind to the antigens
- B cell present antigens on its surface (antigen presenting cell)
- Antigens enter B cells by endocytosis
- Specific response
- B lymphocytes + antigens in blood or tissue fluids
- Barriers
- Eyelashes
- Tear ducts
- Skin
- Nasal and ear cavity hairs
- Mucus in ears nose and mouth
- HCl in stomach
- Antibodies
- Y shaped structure - top is the variable region and the base is the constant region
- Held together by disulphide bridges
- Has 2 heavy chains and 2 light chains
- Active immunity
- Vaccines containing dead or inactive pathogens
- Induce the bodies primary response to build up memory t cells for the antigen
- Passive immunity
- Blood from mother to fetus causes the baby to have the same antibodies as the mother
- Blood transfusions introduces antibodies into the receiving patient
- Breast milk allows antibodies to be shared from mother to baby
- Herd immunity
- Over 90% of the population is immune
- HIV and Aids
- Follows a lysogenic cycle- hides and replicates in healthy cells and presents itself as a 'self' cell so white body cells don't attack it
- Attaches to CD4 proteins on helper t cells and injects viral enzymes and viral RNA turns to DNA and fuses with the TH cell's DNA and more HIV cells are created
- Monoclonal antibodies
- 1. An antigen is injected into a mouse
- 2. The mouse naturally produces lymphocytes, which produce antibodies specific to the antigen
- 3. Spleen cells which produce the lymphocytes are removed during a small operation
- 4. The cells are fused with cancerous white blood cells called myeloma cells to form hybridoma cells which then divide
- 5. These hybridoma cells divide and produce millions of monoclonal antibodies specific to the original antigen
- Phagocytosis
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