Topic 3 - Infection And Disease Flashcards
why is the maximum temperature of 25 degrees Celsius recommended for cultures in school labs?
It reduces the likelihood of growing harmful MO’s to humans
how big are bacteria cells
1 micro metre
What does non-communicable mean?
Non infectious disease cannot be passed from
one organism to another
What is a communicable diease?
A disease that is infectious
passed from person to person
by pathogens
Factors that affect health
Diet
Life Situations
Stress
List some life situations which may affect health
-pollution
. part of world you live in (e.g. more
chance or malaria in certain countries)
- Gender
-Financial status (food availability)
- ethnic group
. How many children you have
. Local sewage and rubbish disposal
- levels of free healthcare provided where you live
What health problems can stress inflict ?
. too much stress can cause
heart disease, some cancers,
mental health problems
In which way can diet affect health?
- Unbalanced diet can lead to obesity which can further lead to diabetes
- Not enogh to eat e.g starvation, malnourishment
-Incorrect nutrients e.g no iron can lead to anaemia
Too much food can lead to obesity or type 2 diabtes and some cancers
What is a pathogen ?
Microorganisms that cause disease
What is a protist?
protist-single-celled organism that can cause
a range of diseases in animals and plants
They are paracytes
Reproduce sexually in mosquito and asexually in the human body
What is the immune system?
The human bodies defence system
What does the skin secrete as a defence mechanism?
Oil/ antimicrobal substances
List the human defences of microbes or pathogenic entry
Non specific(target all pathogen):
-saliva
-tears(contain lycazide which which dissolve the cell wall of bacteria preventing infection
-stomach acid(PH 2)
-Ear wax
-Mucus in openings(mucus also in lungs)
-Scabbing
-Hairs in airways
Specific defence mechanisms:
White blood cells
How does the skin prevent pathogenic entry?
Acts as a phycsical barrier to microbes. If broken blood clots form to seal the wound to prevent microbe entry
How do tears prevent pathogenic or microbe entry ?
Contains lysozyme which dissolves some bacteria’s cell walls preventing infection
How do mucus and cilia in the nose,throat and lungs prevent pathogenic entry ?
Helps trap microbes, and sweep them out of the air passage ways cilia in thorat move particles of microbes to the back of the throat so they can be swallowed into the stomach
How does stomach acid prevent pathogenic or microbial infection?
Kills most of the microbes in our food. Hydrochloric acid in stomach has a PH of 2
what do we call conditions without microbes?
aseptic or sterile
what do culture media usually contain?
carbs and mineral ions
what equipment is used to transfer MO’s onto a culture media?
Inoculating loop
How do you prevent MOs from the air contaminating the petri dish?
seal the lid with tape
why is the maximum temp of 25 degrees Celsius recommended for the incubation of cultures in school labs?
It reduces the likelihood of growing harmful MOs to humans
what important procedures do you carry out before and after working with MOs?
washing hands
swabbing benches with disinfectant
Why would you heat an inoculating loop in a Bunsen burner until it is red hot?
to sterilize it