Biology Y9 Medicines Flashcards
name 6 external defences for humans
tears, nose and ear hairs, urinary tract, cilia and mucus in trachea, skin, stomach
how do tears protect you
they are antimicrobial lysozyme chemicals
how do nose and ear hairs protect you
the wax/mucus catch airborne pathogens
how does the urinary tract protect you
regular urination helps keep the urethra clear of pathogens
how do cilia and mucus in trachea protect you
mucus catches pathogens and cilia are hair-like structures that waft mucus up
how does skin protect you (3 ways)
antimicrobial secretions (sebum), acts as a barrier, commensal bacteria
how does the stomach protect you
hydrochloric acid destroys pathogens
how do scabs protect you
platelets found in blood form a ‘clotting cascade’ whe they detect damage to skin/blood vessel where the platelets, red blood cells and a type of protein form clots/scabs.
what is an internal defence
a defence which only plays a role when pathogens/.foreign material gets into healthy tissues
what steps do white blood cells follow before attacking pathogens/foreign material
1) recognise that there is a pathogen/infected cell present
2) recognise foreign antigens
what does a white blood cell do after recognising foreign antigens (3 steps)
1) phagocytosis (engulfs the pathogen)
2) produce antibodies
3) produce antitoxins
what is an antibody
a Y-shaped protein that sticks to pathogens to target them for destruction
what do antitoxins do
reduce the effect of bacterial toxins
once a foreign antigen is detected, a white blood cell which is specific and ______ will activate
complementary
what does a memory cell do
remembers the antigen and recognises it faster, for a bigger and quicker response (antibody production)
what does a plasma cell do
produce millions of antibodies
where are the antibodies released
into the blood
what do antibodies bind to
the specific antigens
what do antibodies do to pathogens (3 things)
kill pathogens, stick pathogens together, mark pathogens for destruction
when do antibodies stop being produced
once the infection has been cleared
what are memory cells
copies of the plasma cell stored for later
what happens upon re-exposure to a pathogen
the response is bigger and faster - often no symptoms
what does the peak number of antibodies mean
pathogens are gone and antibodies aren’t needed
what is immunity
if you become infected a second time the response is bigger and faster
how does vaccination work
a dead or inactive version of a pathogen is used to stimulate a safe immune response
where is a vaccine introduced
into our body
what is herd immunity
if a large proportion of a population is immune to a disease, the ability for the pathogen to spread is greatly reduced
what is the mortality rate of Ebola
50%
why should you vaccinate (3 reasons)
1) protect yourself from serious diseases
2) cheaper to vaccinate than to treat disease
3) less of a societal burden
how to treat viral infection
antivirals
how to treat fungal infection
antifungals
how to treat bacterial infection
antibiotics
what do painkillers do
relieve the symptoms
do painkillers affect the pathogen
no
where are disinfectants applied
onto objects and surfaces
what do disinfectants do
destroy most biological tissue/cells including human cells
where are antiseptics applied
to wounds
what do antiseptics do
help remove infectious pathogens before they infect the tissue around the wound
what do antiseptics allow to happen
many patients can survivefrom surgery without infection
who first attempted antiseptics and when
Joseph Lister in late 1800s
what do antibiotics do
specifically damage bacteria and not human cells
what do antibiotics ultimately cause to happen
kills pathogens or stops them reproducing
what does a larger zone of inhibition mean
the antibiotic/antiseptic is more effective
what does a smaller zone of inhibition mean
the antibiotic/antiseptic is less effective
what does digitalis come from
foxgloves
what does aspirin come from
willow trees
who discovered penicillin
Alexander Fleming
what is a good medicine (5 things)
efficient (efficacious), safe, stable, easy to administer, successfully taken and removed from the body
what are drugs researched on (in order)
1) cells/tissue cultures
2) small animals e.g. rats, mice, rabbits
3) larger animals e.g. horses, dogs
4) humans
what are clinical trials
trials done on humans
what are the steps of trials on humans
1) healthy humans - test for side-effects/toxicity
2) patients with disease - test for efficacy and safety
3) bigger groups of patients - test efficacy and safety
4) peer review
what is peer review
other scientists reviewing the data
why is peer review used
to remove bias from the trial
what are double blind trials
there are two groups - one gets the drug and one gets a placebo - does nothing
why are double blind trials used
to remove the psychological effect
