infection and response Flashcards
(32 cards)
communicable disease
pathogens are microorganisms that enter the body and cause communicable disease (infections) plants and animals can be infected by them
bacteria
are small cell sthat reproduce very quickly in body and produce toxins that make you feel ill damaging your cells and tissues
viruses
are much smaller than bacteria they can also reproduce very quickly in the body virusis live inside the cell where they replicate then burst out of the cell releasing the new virus
protist
are eukaryotes multicellular some are parasite sthat live on or isnideother organisims often carried by a vector
fungi
are sometimes single celledothers have hyphae that grown and penetrate human skin and the surface of plants they can produce spores which can spreadto other places
how pathogens are spread
can be spread in
water-drinking dirty water
air- carried by air breathed in cough
direct contact- touching contaminated surfaces including the skin e.g athletes foot
viral diseases
measles
hiv
tobacco mosaic virus
measles
spread by droplets of liquid from sneezesand coughs symptoms include red rash and fever can be serious or fatal can lead to pneumonia most people are vacinated when young
hiv
spread by sexual contact of exchanging bodily fluids can be controlled by anti viral drugs stops the virus replicating the virus attacts the cells in the immune system if the system is badly damaged and cannot handle any other infections this is the late stage called aids
tobacco mosaic virus
affects pplants parts of the leaves become discolloured this means plants cannot carry out photosynthesis affecting plants grown
fungal disease
rose black spot shows black spots on leaves of plant meaning less photosynthesis occurs as a result plamt doesnt grow well spread by wind or water can be treated with fungisides taking leavesof infected plant
protist disieiase
malaria is caused by a protist, mosquitoes are the vectors they becomeinfected when they feed on infected animal protist inserte dinto blood vessel malaria fever throw up can be fatal
salmonella bacterial disease
causes food poisoning symptoms stomach cramps vomiting and diarrhoea symptoms caused by toxinsproduced by bacteria most poultry have vacination against salmonellain uk
gonorrhoea bacterial disease
sexuallyt transmitted disease passed on bysexual contact. pain when urinating thick yellow or green discharge from penis or vagina should be treated with anti biotics and use condom,
how to prevent spread
wash hands
destroying vectors by insecticides or destroying habitat#
isolation and infected persom
vaccinatipm people cant develope infection and passs it on
fighting disease defence system
1.skin acts as a barrier to pathogens
2.hair and mucus innose trap particles
3.trachea and bronchi secrete mucus to trap pathogens also have cillia which move backarfds and forwards tgo transport mucus toward throat traps pathogens mucus is swallowed
4.stomach conatins hydrochloric acid to kill pathogens enter body via mouth
immune system
kills pathogens that eneter body
phagocytosis
when white blood cells engulf pathogens then digest them
white blood cells
neutralise the toxins produce toxins, produce antibodies pathogens have anti bodies pathogens have antigens on surface antibodies lock onto antigen destroy pathogen specific to one antigen will only work on that pathogen
vacinations
developed to protect us from future infections involves a dead or weaskened version of the pathogen carry antigens which cause your body to produce asntibodies which will attack the pathogen if you are infected again white blood cells can produce antibodies quickly
painkillers
disease, relieve the pain and symptoms but do not tackle the cause
antibiotic
diseasew, kill the bacteria cuaing the problem but do not work on the virus viruses are very difficult to kill becayse thye live into body celkls
three stages in drug testing
pre- clinical trial
clinical testing
placeebo
placebo effect
double blind trial
pre- clinical testing
drugs are tested on human cell and tissue and tested on living animals
