Health and pathogens Flashcards
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
Exercise
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
Metabolic rate
Cholesterol level
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
Ingesting 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)?
Penicillin
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
