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- To protect the body from pathogens
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- Micro-organisms that cause disease
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- Simply prevents entry of pathogens
- Non-specific
- Has a similar response to all pathogens
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- Skin is a physical barrier that prevents the entry of pathogens
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- Sebaceous gland secretes sebum
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- Lubricates the skin to prevent it cracking
- Also contains chemicals that prevent the growth of bacteria
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- Traps pathogens in a sticky substance
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- By thin cells called mucous membranes
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- In the lining of tracts
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- Respiratory tracts
- Digestive tracts
- Human reproductive tracts
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- Lyzosyme
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- Breaks down bacterial cell walls
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- Tears
- Sweat
- Saliva
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- Ciliated cells
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- Cells that have hair like projections on the outside of them
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- Cilia
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- Move mucous trapped pathogens towards the pharynx (throat) where it will be swallowed into the stomach
- HCL will kill the pathogens
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- Kills any living organisms or pathogens that enter the stomach
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- Mutualism
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- When both organisms benefit
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- Prevents the growth of pathogenic bacteria
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- Bacteria present in the vagina produces lactic acid which creates an acidic environment which prevents the growth of pathogenic bacteria
- Bacteria present in the large intestine suppress the growth of pathogenic bacteria
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- White blood cells
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- Monocytes
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- Phagocytes
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- The destruction of pathogens by white blood cells
- Production of proteins that kill or prevent pathogens from reproducing
- Inflammatory response
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- When cells are invaded they secrete chemicals which attract white blood cells (phagocytes)
- These phagocytes move towards the bacteria
- Engulf the bacteria
- And then secretes enzymes onto the bacteria which kills and digests the bacteria
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- Macrophage
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- Some will move around the body acting as a scavenger for pathogens
- Others will be fixed in lympatic tissues
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- Spleen
- Lymph nodes
- Tonsils
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Through areas becoming :
- Red
- Hot
- Swollen
- Painful
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- Fever
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- If pathogens are needed to be destroyed:
- It becomes swollen due to extra blood
- Vasodilation occurs
- This is the widening of the arterioles
- This means more blood enters this part of the body and in turn more white blood cells (macrophages)
- A higher temperature also speeds up the response
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- System of proteins clump together and bursts bacteria cells
- Also attracts macrophages
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- Interfere with viral replication
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- When cells are attacked by viruses, they produce proteins called interferons
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- Interferons travel to uninfected cells to warn them about a virus
- These cells then produce chemicals to prevent viral replication
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- An antigen is a molecule found on the surface of cells that identifies them as foreign to your immune system
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- Stimulate the production of anti-bodies
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- Protein
- Carbohydrate
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- Your body has its own biological markers that identify as self (not foreign) and so does not attack
- Therefore foreign antigens stimulate an antibody response
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- Cancer cells
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- Lymphocytes
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- Red bone marrow
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- Red bone marrow
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- Blood
- Lymph nodes
- Other lymphatic tissue
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- Spleen
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- Liquid part of the body
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- Cell division
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- Produce the specific antibody required
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- Protein produced in response to a specific antigen
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- Attach to any foreign antigens marking them for macrophages
- Activate the compliment system of proteins (burst bacteria)
- Clump pathogens together to allow for easier phagocytosis
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- To remember specific antigens
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- When that antigen is encountered again, the memory B cells can make the particular plasma cell that produces the complimentary antibody, and more memory B cells
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- Red bone marrow
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- Thymus gland
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- Lymph nodes
- Other lymphatic tissue
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- When cells become infected or cancerous
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- Recognise specific antigens
- Stimulate B cells
- Stimulate killer T cells
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- The immune system is not fully turned on and lowers the immune response
- B Cells cannot make the specific antibody for the pathogens
- Killer T cells will not be activated to fight the pathogens
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- HIV
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- Recognise specific antigens
- Kill and destroy infected cells
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- Killer T cells attach to the antigen of pathogen
- Secrete perforin
- Perforin breaks down the cell membrane of infected cells
- This causes them to fill with water and burst
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- Lysis
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- Remember the specific antigen
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- Memory T Cells trigger the production of B Cells and T Cells much quicker if the pathogen re-enters the body
- Live for a long time
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- Turns off the immune response when pathogens or infected cells have been dealt with
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- Limit B cell activity to stop the production of antibodies
- Limit killer T cell activity
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- Each B cell has a specfic antigen that it attaches to
- Only the antibody for that specific antigen will be activated
- Each T cell has a specific antigen receptor on their surface
- These antigen receptors will only attach to one particular type of antigen
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- The first time an antigen is encountered by the body it takes time to adapt to it
- It takes time for the B cells to activate and for the correct antibodies to be produced in sufficient amounts
- It can take up to two weeks for a sufficient amount of antibodies to be produced to deal with the new antigen
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- Secondary response is faster and more efficient
- Memory B and Memory T Cells remain from the first encounter
- Immune system knows how to produce the plasma B cells and T cells
- Plasma B cells produce the antibody required quickly and in response to a small amount of that antigen
- Correct antibody is produced faster and in large quantities
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- The body's ability to resist infection
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- The ability to resist disease by the production of antibodies
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- non-harmful (or weakened) dose of a pathogen or just the antigen of that pathogen
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- To stimulate the immune system to respond
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- A vaccine is a non-harmful dose of a pathogen or just the antigen of that pathogen
- This foreign antigen causes specific B cells and T cells to activate
- B Cells will divide and produce plasma cells to produce specific antibodies required and also memory B cells
- Memory T cells will also be produced due to helper T cells recognising the antigen and producing memory T cells when fully active
- It is the production of these memory B and T cells which will give rise to long term immunity
- Vaccination is all about causing the immune system to react and produce those memory cells
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- Organism produces their own antibodies and B and T Cells
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- The body is forced/induced to make antibodies due to foreign antigen entering body
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- Flu pathogen enters through the skin
- Immune response by B and T cells
- Antibodies are produced in response to antigen
- Memory B and T cells are also made
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- The body has been made/forced to make the antibodies artificially
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- Vaccination
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- Receive antibodies which have been made in a different organism
- No antibodies made naturally
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- Baby receiving antibodies through breastfeeding from mother
- Baby receiving antibodies through placenta in uterus of mother
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- Receive antibodies from tetanus injection
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- Short lived
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- Antibodies only survive until they are broken down
- No memory T or B Cells are made