Flashcards in Health and pathogens Deck (21):
Describe a "healthy diet"
One which contains the right balance of different foods and the right amount of energy
What are carbohydrates, fats and proteins used for by the body?
Mineral ions and vitamins (in general terms)?
Releasing energy and building cells
Small amounts of healthy functioning of the body
What happens if a person's diet is not balanced?
They are malnourished, which may lead to being over- or underweight, and could also lead to deficiency diseases or conditions such as Type 2 diabetes
What happens when the energy content of food taken in is less than the amount of energy expended by the body?
How is this level of energy expended increased?
The person loses mass
Define metabolic rate
How does it vary?
The rate at which all chemical reactions in the cells of the body are carried out
The amount of activity one does, one's proportion of muscle to fat, and inherited factors
Give two examples of when inherited factors affect our health
What is the general trend between the activity/amount of exercise and overall health?
Someone who does lots of exercise is healthier than someone who does little
Define a pathogen
A microorganism that causes infectious disease
How do bacteria and viruses make us feel ill?
They reproduce rapidly inside the body and may produce toxins/poisons that make us feel ill
Viruses damage the cells in which they reproduce
Give three ways in which white blood cells help to defend against pathogens
Producing antibodies, which destroy specific bacteria or viruses
Producing antitoxins, which counteract the toxins released by the pathogens
How does immunity to a pathogen come about in the body?
The immune system produces specific antibodies to kill a specific pathogen, then stores them, so that it can react quickly and destroy that pathogen in the future. Sometimes, dead or inactive pathogens can trigger white blood cells to produce antibodies (such as in vaccination).
Summarise Semmelweis' findings
He insisted that doctors washed their hands before contacting and examining patients, which greatly reduced the number of deaths from infectious diseases in his hospital. He thus discovered that washing hands prevents the spread of these diseases
What are antibiotics used for, and name the first one to be discovered (Alexander Fleming)?
Medicines that help cure bacterial disease by killing certain bacteria within the body. They can NOT kill viral pathogens (viruses), which live and reproduce inside cells.
How do we avoid antibiotic resistant strains of bacteria arising?
Specific bacteria should be treated with specific antibiotics to avoid bacteria becoming resistant to antibiotics
Use minimal quantities, only with a serious bacterial infection (not for things like a mild throat infection)
Develop new antibiotics continually
How do pathogens (say, MRSA) produce strains that are resistant to an antibiotic (say, methicillin)?
Why is this dangerous?
Mutations produce new strains, some of which happen to be resistant to the antibiotic
Antibiotics kill the original, non-resistant pathogens - resistant ones survive and reproduce, passing on genetic immunity
The resistant pathogens spread rapidly and often are dangerous because there is no effective treatment
Why do painkillers and other medicines help with an infectious disease?
Why are they no good by themselves?
They relieve symptoms, making the person feel well
They do not kill the pathogens that are causing the problems
What is the MMR vaccine?
A vaccine used to protect children against measles, mumps and rubella
When an uncontaminated culture of microorganisms is required for investigating the action of disinfectants and antibiotics, what steps must be taken to prevent contamination?
Petri dishes and culture media sterilised before use
Inoculating loops used to transfer microorganisms to the media sterilised by passing through a flame
The lid of the Petri dish secured with adhesive tape to prevent airborne contamination
In school and college laboratories, what maximum temperature are cultures incubated at? Why?
Why are higher temperatures used in industrial conditions?
25ºC, to reduce the likelihood of growth of pathogens that might be harmful for humans (these would be adapted to thrive at about 37ºC)
To produce more rapid growth
What are the advantages of vaccination?
Prevents illness in individuals and populations
Vaccination is often cheaper than treating the illness at a developed stage
Chances of getting seriously ill/dying from side effects much lower than the same from getting the illness