T3 infectious diseases Flashcards
define pathogen
pathogens are microorganisms that cause infectious diseases
name 4 pathogens
bacteria
virus
fungi
protists
what do bacteria cells do inside the cell?
- once inside the human body bacteria reproduce rapidly
- they release harmful chemicals and toxins
viruses cannot reproduce by themselves but what can they only reproduce inside?
a host cell
what is the first symptom of measles?
a fever
how are measles spread?
through droplets eg when a person coughs or sneezes
what can measles damage?
breathing system and brain
what is the treatment for measles?
a vaccine
what is the first symptoms of HIV?
a flu-like illness
what does the virus attack during HIV?
the patients immune system
what happens when the immune system is severely damaged?
it can no longer fight off cancer cells and other infections
what is the treatment for HIV?
antiretroviral
what causes salmonella food poisoning ?
ingesting infected food
what are the symptoms of salmonella?
fever
vomiting
diarrhoea
cramps
what can bacteria be treated by?
antibiotics
how is gonorrhoea spread ?
by sexual intercourse
what can stop gonorrhoea from spreading?
condoms
an std test
how can u stop malaria from spreading?
drain still water as they breed in these areas
spray areas with still water with insecticide which kill them
mosquito net
what is the job of non-specific defence systems?
to prevent pathogens from entering the human body
what is the largest organ in the body?
the skin
what does the skin do?
its a protective layer around the body
what does the outer layer of the skin insist off?
dead cells which make it difficult for the pathogens to enter and penetrate
what is the oily substance called that the skin forms?
sebum
what does the sebum do?
the sebum kills bacteria
what do the nose hairs and mucus do?
trap pathogens from entering the breathing system
what are the trachea and bronchi covered with?
cilia which are tiny hairs
what are cilia covered in and what does this do?
mucus which trap pathogens
where does the cilia waft the mucus upwards to and what happens after?
to the throat which is swallowed into the stomach
what does the stomach contain which kill pathogens?
hydrochloric acid
what are the 2 advantages of the immune system?
destroy pathogens and toxins
protect us from the same type of pathogens invading us in the future
what does the immune system involve?
white blood cells
what is the process of phagocytosis?
the white blood cells detects chemicals that are released by pathogens
the wbc ingests the pathogens
the wbc used enzymes to destroy pathogen
what are antibodies?
protein molecules produced by white blood cells
what are 2 characteristics of antibodies?
they are specific
remain in the blood for a long time which means it can protect us from the same pathogen that enters the body again
what are 2 things white blood cells produce
antibodies
antitoxins
what do antitoxins do?
stick to toxin molecules
prevent them from damaging cells
what does TMV cause
plants discolour in mosaic pattern
what does the discolouration in a plant mean?
rate of photosynthesis is reduced
define antibiotics
kills infective bacteria without killing body tissue
what was the first antibiotic?
penicillin
why cant antibiotics kill virus?
because viruses reproduced rapidly and need an antiviral
what is antibiotic resistance?
when bacteria can no longer be killed as they’ve evolved
specific antibiotics are given on?
specific bacteria
what is a treatment of bacteria to relieve symptoms?
painkillers to relieve pain but not kill pathogen
what was foxglove used for?
heart drug digitalis
what was aspirin made from?
willow tree
what did Alexandra flemming discover?
penicillin drug from the mould penicillium
what are the 3 things that are needed for a new drug
dose
effective
toxicity
what is preclinical testing
testing done by cells tissues or live animals
what are the stages of clinical testing
testing done by healthy humans
take low doses to check safety
doses increase until it reaches optimum and has the least side effects
what is the double blind trail
the test group is given the drug
the placebo group is given dummy drug
both groups don’t know what drug they gave to stop ppl from being bias
