TOPIC 3 INFECTION AND RESPONSE Flashcards
what is a pathogen
microorganisms that enter the body and cause communicable diseases
-BOTH plants and animals can be infected
how does bacteria make us feel ill
-small cells that produce toxins that damage your cells and tissues
what makes us feel ill in viruses
-they live inside cells and replicate using cell machinery to produce many copies of themselves
-the cells burst which releases new viruses
state 3 ways pathogens are spread
- contaminated water, (drinking dirty water)
- air (pathogens can be carried in air and breathed in)
- direct contact (by touching contaminated surfaces e.g skin)
explain the viral disease measles
-spread by droplets from an infected persons sneeze or cough
-affect a red skin rash and fever
-leads to pneumonia
-prevent, vaccinated when young
HIV virus
-spread by sexual contact or exchanging bodily fluids
-affect flu-like symptoms
-attacks immune cells
-controlled by antiretrovial drugs
what is the disease TMV
-tobacco mosaic virus
-affects many species of plants
-cause a mosaic pattern on leaves (discoloured)
-**effect **plant cannot carry out photosynthesis
state a fungal disease
rose black spot
-causes purple or black spots to develop on leaves and the leaves turn yellow and drop off
-spreads through environment in water or by wind
-**treat **by stripping the plant of its affected leaves
state a disease caused by a protist
malaria
-mosquitos are vectors that pick up malarial protst when they feed on infected animal
-every time the mosquito feeds on another animal it infects it
causes repeated fevers
-reduce spread by mosquito nets or stopping them from breeding
state 2 bacterial diseases
-salmonella
-gonorrhoea
what is salmonella
-a type of bacteria that causes food poisoning
-causes fever, stomach cramps, vomitting
-get it by eating contaminated food
-most poultry in UK is given a vaccination against this
what is gonorrhoea
-sexually transmitted disease (STD)
-**transmitted by sexual contact
-symptom pain when urinating, yellow discharge from the vagina
-treated by **antibiotics
-use condoms to stop spread
4ways to reduce disease
- be hygenic, wash hands with soap thoroughly
- destroy vectors
- isolate infected individuals
- vaccinations
how does the skin act as a defence system
-acts as a barrier to pathogens
how does your nose act as a defence system
-hair and mucus trap particles that contain pathogens
how does the trachea and bronochi act as a defence system
they secrete mucus to trap pathogens
-lined with cilia
how does the stomach act as a defence system
-produces hydrochloric acid
what does the immune system do if pathogens enter the body
-kicks in to destory them
-the white blood cells travel around and when coming across an invading microbe they
* consume them
* produce antibodies
* produce antitoxins
describe the 1st process of white blood cells
-engulf cells and digest them
-called phagocytosis
describe the 2nd process of white blood cells
-invading pathogens have antigens on its surface
-start to produce proteins called antibodies
-antiboides are produced rapidly
-if the person ifnected with the same pathogen again, the persons naturally immune to that pathogen
3rd process of white blood cells
-produces antitoxins
-counteract toxins produced by invading bacteria
how do vaccinations protect from future infections
-inject small amounts of dead or inactive pathogens that carry antigens
PROS of infections
-they control many communicable diseases that were common
-outbreaks of diseases can be prevented if a large percentage of the population is vaccinated
CONS of infection
-dont always work
-can causes bad reactions, e.g swelling or fever
state what relieves symptoms
-painkillers
how do antibiotics help
they kill bacteria but dont destory viruses
3main stages of drug testing
- preclincal testing, drugs are tested on human cells and tissues in the lab
- test drug on live animals
- tests for efficacy
- tests toxicity
- LAW must be tested on 2different live mammals - if passes them tests its treated on human volunteers in a clincial trial
-then tested on people suffering from the illness
