B5 - communicable diseases Flashcards
what are communicable diseases caused by
pathogens (like bacteria and viruses)
what is a non communicable disease
a disease that cannot be transmitted from one person to another
what three factors can affect health
diet
stress
life sotuations
how does your diet affect your health
not eating enough/the right nutrients - can lead to anaemia, starvation, or rickets
too much food/not the right food - can cause obesity, some cancers, type 2 diseases
how can stress affect health
increased risk of heart disease, certain cancers, and mental health problems
what life situations can affect your health (x7)
where you live in the world
gender
financial status
ethnic group
levels of free healthcare you can access
amount of children
local sewage and rubbish disposal
how do viruses and cancers interact
viruses living in cells can trigger changes that lead to cancers
how does a defective immune system lead to health problems
it may not work properly
may result in poor nutrition or infections like HIV/AIDS
how can immune reactions caused by a pathogen affect allergies
they can trigger allergies to factors in the environment like skin rashes hives or asthma
how are physical and mental health linked
severe physical health can lead to depression and other mental illness
what does malnutrition lead to in health problems
deficiency diseases
weakened immune system
obesity
cardiovascular diseases
type 2 diabetes
cancer
what are the most common pathogens in plants
viruses and fungi
what are bacteria
single called living organisms used to make yogurt, cheese, treat sewage, and make medicines
how do pathogens cause diseases
bacteria divide rapidly by binary fission, produce toxins that affect your body
viruses take over cells of your body, live and reproduce inside cells, damaging and destroying them
how do pathogens spread by air
when you are ill you expel tiny droplets full of pathogens from your breathing system
other people pick up the infection through the air
how are pathogens spread by direct contact
plants/people directly touch skin or flesh spreading the disease
some are spread through blood like HIV AIDS and hepatitis
how are pathogens spread by water
fungal spores in splashes of water spread plant disease
drinking contaminated water or undercooked food can spread pathogens
describe the process of growing microorganisms in the lab
pour hot agar gel into a sterilised petri dish
leave it to cool and set
inoculate the agar using uncontaminated cultures of microorganisms
incubate the petri dishes and store them upside down
why must you keep petri dishes upside down
so condensation does not fall from the lid to the surface and contaminate it
what is a culture medium
a liquid or gel containing nutrients to feed the bacteria
contains carbohydrates, minerals, nitrogen source and sometimes other chemicals
what temperature must cultures be incubated at in a school environment
25°C to reduce the likelihood of harmful pathogens growing
what temperature does bacteria have to be grown at in a school environment and why
25°C to reduce the likelihood of harmful pathogens growing
how do you calculate the number of bacteria in a population
calculate how many times the bacteria will divide in an hour, then multiply to to apply to the amount of hours it will be growing
times the bacteria at the beginning of the growth period by 2^number or divisions
how do you prevent bacterial growth
raise or lower the temperature
use chemicals to stop them growing/kill them (disinfectants, antiseptics)
what are antibiotics
chemicals that can be used in our bodies which kill bacteria
how do you calculate the effectiveness of disinfectants and antibiotics
find the area of inhibitions (pi x r^2)
what did ignaz semmelweis discover
that his medical students weren’t washing their hands between procedures, one student died from similar symptoms to childbed fever
what changes did ignaz semmelweis make
made his medical students start washing their hands
less people died
what did louis pasteur do
develop vaccines against diseases like anthrax and rabies
what did joseph lister do
used antiseptic chemicals to destroy pathogens in operating theatres
how do you prevent the spread of pathogens through hygiene
hand washing
using disinfectants
keeping raw meat away from food
coughing or sneezing into handkerchiefs
maintaining hygiene of people and agricultural machinery
how does isolating infected people stop the spread of disease
fewer healthy people will come in contact with the infected person