infection and response/ defence against diseases Flashcards
types of microorganisms
bacteria, viruses, fungi, protists
types of cells
eukaryotic - has nucleus eg. plant and animal cells + prokaryotic - don’t have nucleus eg. bacterial cells
what is a communicable disease?
infectious disease - can be spread from one person to another eg. covid, flu
ways of spreading?
air - pathogens can be carried in air and inhaled
direct contact - touching contaminated surfaces
water - drinking or bathing in dirty water
ways to prevent pathogen spreading
hygiene - washing hands
social distancing
disinfecting surfaces
wearing masks
isolation
vaccination
what is the first line of defence against pathogens in the body?
skin
nose
throat
stomach
how is the skin a good first line of defence?
skin flora - good bacteria and viruses on surface of skin
skin flora compete with harmful bacteria and viruses for nutrients and space
how is the nose adapted to be a good first line of defence?
mucus to trap pathogens and hair to move out
what is a pathogen?
bad micro organism
how is throat adapted to be a good first line of defence?
mucus produced to trap microorganisms
cilia (hair-like structures) move mucus out the throat
how is stomach adapted to be a good first line of defence?
stomach contained hydrochloric acid which kills pathogens
what is one thing white blood cells do to protect body when pathogen has gotten past first line of defence?
white blood cells engulf and consume the pathogens - phagocytosis
what is another thing white blood cells do to protect body when pathogen has gotten past first line of defence?
white blood cells produce antitoxins - these antitoxins destroy toxins produced and released by bacteria but not efficient way of protecting body
what is a last thing white blood cells do to protect body when pathogen has gotten past first line of defence?
produce antibodies that attack the pathogen.
why can’t one antibody work for all pathogens?
antibodies are specific to the pathogen - which is why they take long to make. they need to be able to fit to the antigens (proteins on the surface of the pathogens) to slowly destroy the pathogen this is also why once an antibody is made against a specific pathogen, the body is immune to that pathogen
what are antibiotics for?
for bacteria only
what is a vaccine?
an injection containing weak or dead pathogens
why are vaccines helpful?
white blood cells will produce antibodies for the weak pathogens until the antibody that is specific to the pathogen is made. if the real pathogen enters the body later, the white blood cells quick produce the specific antibodies to kill the pathogen and the vaccinated person is immune eg. covid 19 vaccine
what is mutation?
when the antigens and dna of the pathogen changes so the person is no longer immune
why should you not take too many antibiotics?
because the bacteria can develop resistance to the antibiotics
what is an antibiotic sensitivity testing experiment look like
determines if the antibiotic will be affective against bacterial infection
