Flashcards
How does the immune system eliminate pathogens which live outside cells?
Cards in this deck (33)
- 1How many lymph nodes does the average individual have?60-70
- 2What are the spleen and Peyer's patches classified as?Secondary lymphoid organs
- 3When might the number of secondary lymphoid organs increase?During an infection - e.g. lymph nodes form develop around arthritic joints
- 4Explain how antigens reach adaptive cells.Fluid drains from tissue (i.e. infection in serious cut) into nearby lymph nodes. Within two hours macrophages and neutrophils will be active at the site of infection. DC encounters the pathogen at the site and drain along with the fluid to lymph nodes where they present to T helper cells.
- 5What happens if T cells recognise the antigen? Why do symptoms develop progress?1) Rapidly proliferate over a 4-5 day period. Clonal expansion of T/B cells causes the lymph nodes to swell.
2) Because the pathogen divides more rapidly than the cells of the adaptive immune system - 6Why do diseases which are novel to us as a species present more of a problem?More likely to cause serious injury or death because out immune cells is not primed for it.
- 7Where do worms live?In the interstitial fluid
- 8How does the body try to deal with pathogens in the blood/lymph/interstitial fluid? (3)1) Antibodies
2) Complement
3) Phagocytosis - 9How does the body try to deal with extracellular pathogens located at the epithelial surfaces? (2)1) Antibodies (IgA)
2) Antimicrobial peptides - 10How does the body try to deal with worms?Can't really kill them - have to try to make the environment as hostile as possible by secreting histamine and leukotrienes. IgE antibodies produced.
- 11Other than by activating other systems how can antibodies protect against external pathogens?Coating them completely so that they can no longer function
- 12What are the two forms of intracellular infection?1) Cytoplasmic - viruses
2) Vesicular - mycobacteria - 13How does the body attempt to deal with cytoplasmic infections? (2)1) Cytotoxic T cells
2) NK cells - 14How does the body attempt to deal with vesicular infections?T cell dependent-macrophage activation. When a cell is intracellularly infected it will either die because of the pathogen or be killed by the immune system.
- 15What is the purpose of the humoral immune system?Destroy extracellular pathogens
- 16What are the components of humoral immune response? (4)1) Antibodies
2) Complement
3) Phagocytosis
4) Antimicrobial peptides - 17What do the following cause: 1) Bordetella pertussis 2) Borelia burgdorferi 3) Campylobacter jejuni 4) Haemophilus influenzae 5) Shigella sonnei 6) Streptococcus pyogenes 7) Yersinia pestis1) Whooping cough
2) Lyme disease
3) Diarrhoea
4) Meningitis
5) Dysentery
6) Scarlet fever
7) Bubonic plague - 18How many people are affected worldwide by hookworms, pinworms and roundworms?Nearly 4 billion - in developing countries, to do with poor sanitation
- 19What are the stages of B cells (before encountering an antigen)1) Stem cells
2) Pro-B cells
3) Pre-B cells
4) Immature B cells - leave bone marrow
5) Mature naive B cells - 20Which antibody is produced in response to an infection in the mucosal membrane? For worms? Can cross the placenta?1) IgA
2) IgE
3) IgG - 21What does Fc stand for in an antibody?Fragment of crystallisation
- 22What is the order of joining?1) D and J
2) V to DJ - 23What is junctional diversity?The same combination of V, D and J will be slightly different because of small differences in the amino acid sequence around the junction - imperfective joining
- 24How many variable domains are there in the heavy chain? Kappa of light chain? Lambda of light chain?1) 300-1000
2) 300
3) 2 - 25How many diversity domains are there in the heavy chain? Kappa of light chain? Lambda of light chain?1) 13
2) 0
3) 0 - 26How many joining domains are there in the heavy chain? Kappa of light chain? Lambda of light chain?1) 4
2) 4
3) 3 - 27What are the total possible number of combinations which can make up the structure of an antibody?375 million
- 28Which antibody is a dimer? Pentamer?1) IgA
2) IgM - 29How many antigen binding sites does IgM have?10
- 30What happens when a mature naive B cell encounters an antigen?Presents to T helper cell - if the T helper cell recognises the pathogen (i.e. it has already encountered it) then the B cell is activated.
- 31What is a myeloma? How can you detect this?Arises when plasma cells become cancerous - look for high levels of IgG
- 32What are the five functions of antibodies?1) Neutralisation
2) Agglutination
3) Opsonisation - for engulfment by macrophage
4) Antibody-dependent cell killing - directs T cell to pathogen
5) Activation of the classical complement pathway - 33What is affinity maturation? Where does it occur?1) B cell makes an antibody with a better fit to antigen (mutases affect the sequence of the variable regions - somatic hypermutation, antibodies which bind for are selected for)
2) Germinal centres in the lymph node and spleen