Flashcards
IMMUNITY
Flashcards do conjunto (93)
- 1Name some parts of the body in which lymphocytes (white blood cells are found)Blood, lymph and tissue fluid
- 2What is the difference between specific and non specific defence mechanisms?Non specific - don't distinguish between pathogens; respond to them all in the same way; response is immediate.
Specific - distinguishes between different pathogens; takes longer but provides long lasting immunity - 3Give the two types of non specific mechanismPhysical barrier to entry, phagocytosis
- 4What are the physical barriers?Skin, mucus linings, HCl in stomach
- 5How are phagocytes attracted towards the pathogen in phagocytosis?Chemical products of the pathogen act as attractants
- 6What happens after the pathogen is attached to the phagocyte?The phagocyte ingulfs it
- 7What is the name of the vesicle in which the pathogen is engulfed in?A phagosome
- 8Which structures inside the phagocyte bind to the phagosome and release their contents?Lysosomes
- 9What is in the contents of the lysosomes and what do they do?Enzymes - break down the pathogen by hydrolysis
- 10What happens to the soluble products from the breakdown of the pathogen?They are absorbed into the cytoplasm of the phagocyte
- 11Phagocytosis causes ___________ at the site of infectionInflammation
- 12The release of which chemical results in inflammation?Histamine
- 13What does histamine cause the blood vessels to do?Dilate
- 14What does this speed up?The delivery of phagocytes to the site of infection
- 15What are the two specific defence mechanisms?Cell mediated response, humoral response
- 16Which of the two involves T lymphocytes?Cell mediated response
- 17Which lymphocytes are involved in humoral immunity?B lymphocytes
- 18Which mechanism is immunity involving antibodies present in the bodily fluids?Humoral
- 19Cell mediated response using T lymphocytes involves which kind of cell?Body cells
- 20What do T cells respond to?An organisms own cells that have been invaded by non-self material
- 21How can T cells distinguish between invader cells and normal cells?Phagocytes present antigens of pathogen on their own surface, virally invaded body cells present viral antigens on their cell surface membranes, cancer cells present antigens as a sign of distress
- 22What name is given to these types of cell?Antigen presenting cells
- 23What helper T cells do to the antigens on the surface of the phagocyte?Fit onto them
- 24What does this activate?Other T cells to divide rapidly and form clones
- 25What are the 4 things the cloned cells can do?1. Develop into memory cells
2. Stimulate phagocytosis
3. Stimulate B cells to divide
4. Kill infected cells - 26Which part of the T helper cells fit on to the antigen?The specific receptor
- 27What do killer T cells produce and how does it kill infected cells?A protein - makes holes in the cell surface membrane; cell becomes freely permeable and dies as a result
- 28Which type of pathogen are T cells especially effective against and why?Viruses - they live and reproduce inside body cells
- 29Where do T lymphocytes mature?The thymus gland
- 30Where do B lymphocytes mature?Bone marrow
- 31What is 'humor' another word for?Bodily fluids
- 32What do B cells produce?Antibodies
- 33What happens when a specific antibody attaches to an antigen in the blood?The type of B cell that produces it divides rapidly by mitosis
- 34This forms clones. What do these clones all produce?The antibody specific to the foreign antigen
- 35In practice, what do most pathogens have on their surfaces?Many different proteins
- 36What do these all act as?Antigens
- 37What other substances act as antigens?Toxins
- 38Give an example of a pathogen that releases a toxinThe pathogen that causes cholera - vibrio cholerae
- 39What does mean regarding B cells?Many different B cells will clone
- 40What are the two types of cell the clones can develop in to?Plasma cells and memory cells
- 41Which out of the two secrete antibodies directly?Plasma cells
- 42How long to plasma cells survive?A few days
- 43Around how many antibodies can plasma cells produce every second?2000
- 44What do antibodies do?Destroy the pathogen and any toxins it produces
- 45Which stage of immune response are plasma cells therefore responsible for?Primary immune response
- 46How long to memory cells live for?Decades
- 47Memory cells circulate in the _______ and ______ _______Blood and tissue fluid
- 48What happens when memory cells encounter the same pathogen at a later date?They divide rapidly and develop into plasma cells and more memory cells
- 49What do the plasma cells do?Produce antibodies to destroy the pathogen
- 50What do the memory cells do?Circulate in readiness for future infection
- 51Which stage of the immune response are memory cells responsible for and why?The secondary immune response - they are responsible for long term immunity
- 52Why do people get flu more than once?There are many different strains - the antigens of the virus are constantly changing
- 53What name is given to this?Antigenic variability
- 54Why does the body treat every infection like a new one in terms of the influenza virus?There will be no corresponding memory cells to stimulate the production of corresponding antibodies so the body undergoes the primary immune response
- 55Why do we feel the symptoms of the flu each time we get it?The primary response is much slower - in the meantime we develop the symptoms e.g sore throat, high temperature etc
- 56What molecules are antibodies made up of?Proteins
- 57Why does this allow for a vast variety of antibodies?Proteins occur in almost an infinite amount of forms
- 58How many polypeptide chains are antibodies made of?4
- 59What are the two names given to the pairs of chains?Heavy chains & light chains
- 60When the antibody fits onto the antigen, what name is given to this structure?The antigen-antibody complex
- 61Why is the binding site called the 'variable region'?Because it is different for each antibody
- 62What name is given to the rest of the antibody that is the same for each one?The constant region
- 63Many pathogens have many different antigens on its surface. What will this induce when it enters the body?Each antigen will induce a different B cell to multiply and clone
- 64Collectively, what are the antibodies that these B cells known as?Polyclonal antibodies
- 65What is the same given to the antibodies that are isolated and cloned so there is just one type?Monoclonal antibodies
- 66How can monoclonal antibodies be used in cancer treatment?They can attach to the cancer cells and activate a cytotoxic drug which kills the cancer cells
- 67Why does this cause little, if any damage to other cells?The cytotoxic drug is only activated by cells to which the monoclonal antibodies are attached i.e the cancer cells
- 68Monoclonal antibodies can 'knock out' specific T cells - what is this useful for and why?Transplant surgery - there is often rejection due to the action of T cells
- 69Monoclonal antibodies can also be used to separate a chemical from a mixture and in immunoassay. What is immunoassay?A method of calculating the amount of substance in a mixture
- 70What is immunoassay used in?Home pregnancy kits, testing for drugs in the urine of athletes
- 71What were the 2 main struggles with trying to produce monoclonal antibodies?B cells are short lived and only divide inside a living organism
- 72When producing monoclonal antibodies, which animal is exposed to the non self material?A mouse
- 73What do the B cells in the mouse then do?Produce a mixture of antibodies (polyclonal antibodies)
- 74What type of cells are the B cells of the mouse mixed with to enable them to divide outside the body?Cancer cells
- 75Why is this?Because cancer cells divide rapidly outside the body
- 76Why is detergent added to the mixture of B cells and cancer cells?To break down the cell-surface membranes and enable them to fuse together
- 77How are clones of each B cell made from this?They are separated under a microscope and cultured to form a group (clone)
- 78What is each clone tested to see?Whether it is producing the required antibody
- 79What is done to the clones producing the required antibody?They are grown on a large scale
- 80Why are they called 'monoclonal' antibodies?Because they come from a single B cell
- 81What is the name given to the process in which the antibodies are modified so that they work in a human?Humanisation
- 82Why is this necessary?Monoclonal antibodies from a mouse will be recognised as 'non-self' and destroyed by human antibodies
- 83Why is the use of mice in producing monoclonal antibodies an ethical issue?It involves giving mice cancer
- 84Genetic engineering is often brought up in debate when discussing the production of monoclonal antibodies. Why is this?To eliminate the need for humanisation, transgenic mice can be used (giving mice a human gene so they produce human antibodies rather than mouse ones)
- 85What diseases have monoclonal antibodies been successful in treating?Cancer, diabetes
- 86However there have been deaths associated with the use of monoclonal antibodies when treating ________Multiple sclerosis
- 87What is active immunity?When an individual is exposed to a pathogen and becomes immune by producing their own antibodies in response.
- 88What is passive immunity?Immunity by the introduction of the antibodies from an outside source - can be induced by a vaccine
- 89What are 4 features of a successful vaccination programme?Few side effects - must be sufficient quantities to immunise the entire vulnerable population - must be means of producing, transporting an storing the vaccine available - trained staff
- 90A vaccination might not eliminate a disease. Why is this? (5)People may have defective immune systems - antigenic variability - objections to vaccination - people may harbour the pathogen and infect others - some pathogens 'hide' from immune defences
- 91It is difficult to control cholera by vaccination. Cholera is an intestinal disease. Why does this make it difficult?Any oral treatment is rapidly flushed by the diarrhoea, a symptom of cholera
- 92What are two other factors that make cholera hard to control by vaccination?Antigenic variability - mobile populations (due to war, tourism etc) spread the pathogen
- 93Tuberculosis is another disease that is difficult to control by vaccination. There are 4 reasons why. What are these reasons?Increase HIV = increase in defective immune systems; increase elderly population = increase in defective immune systems; many people in overcrowded accommodation; mobile populations
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- Questions and answers on the immunity topic. Includes defence mechanisms, phagocytosis, humoral and cell mediated immunity, antibodies (monoclonal) and vaccination
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- ashiana121
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