topic 5 - health and disease Flashcards
what is the world health organisations definition of health
a state of complete physical, mental and social well-being and not just the absence of disease
what is a pathogen
anything that causes a disease
how can pathogens be transmitted
food and water borne
airborne
direct contact
by bodily fluids
vector borne (1 host to the next i.e insects)
how does our body protect itself
the skin - acts as a physical barrier
tears and saliva - contain lysozomes that kills bacteria
stomach - produces hydrochloric acid that kills bacteria
out breathing organs - produce mucus to cover the lining of these organs and trap microbes
platelets - seals wound by clotting
what are antigens
molecules found on the surface of cells that allow the immune system to recognise foreign cells
what are the names of the 2 types of white blood cell that protect our body from disease
lymphocytes and phagocytes
what are features of a lymphocyte
-big nucleus
-make chemicals called antibodies
-each lymphocyte only makes one type of antibody
-makes antitoxins
what are features of a phagocyte
-tracking
-binding
-engulfs and destroys the pathogen
-produces antitoxins
how do white blood cells protect our body from disease (6 marker)
1) new pathogens attack the body and multiply, this makes you feel ill
2) white blood cells detect the antigens on the pathogens
3) lymphocytes called plasma cells make antibodies to fit the antigens
4) the antibodies attach themselves to the pathogens and kill them
5) white blood cells called memory lymphocytes remember the shape of the antigen
6) pathogens enter the body again
7) white blood cells instantly recognise the pathogens and make antibodies immediately
8)the antibodies attach themselves to the pathogens and kill them before they have a chance to affect us, we now have imunity
what are issues with vaccines
-some people may be allergic
-immuno compromised people (cancer treatment) cannot be given a vaccine
-can be costly
-may be ethical issues
what is the primary and secondary immune response
primary - the body creating the correct lymphocyte with antibodies to destroy the pathogen
secondary - memory lymphocyte makes more antibodies and in a quicker period of time to destroy the pathogen
what can antibiotics not treat
viruses as they live and reproduce inside cells
what are stages of developing medicines
1) pre-clinical stage of testing is done on tissue/cells in the lab to find out if the medicine will have a desired effect/gives an idea of toxicity
2) testing on live animals to find out how body cells are affected
3) small clinical trial to see if it is safe for human intake
4) double blind trial - doctor nor the patient know who has been given the drug to avoid bias and the placebo effects
