Diet and Exercise
Used by body to release energy and to build cells.
Insulation. Used by body to release energy and to build cells.
Growth and Repair. Used by body to release energy and to build cells.
MINERALS & VITAMINS:
Needed in small amounts for healthy functioning of body.
When their diet is not balanced. Leads to person either being overweight or underweight. Can lead to conditions such as Type 2 Diabetes, or deficiency diseases.
Person loses mass when the energy content of the food taken in is less than the amount of energy expended by the body.
Exercise increases amount of energy expended by the body.
Rate of which all chemical reactions in the cells of the body are carried out.
Varies with amount of activity you do and proportion of muscle to fat in your body.
May be affected by inherited factors.
Can affect health e.g Cholesterol level
Microorganisms that cause infectious disease.
Bacteria and viruses may reproduce rapidly inside the body and make us feel ill.
May produce toxins that make us feel ill.
Viruses damage the cells in which they reproduce.
The body has different ways of protecting itself against pathogens.
WHITE BLOOD CELLS:
Produce antibodies, which destroy particular bacteria or viruses.
Produce antitoxins which counteract the toxins released by the pathogens.
Produces specific antibodies to kill specific pathogens. Leads to immunity from that pathogen.
In some cases, dead/unactive pathogens stiumulate anitbody production. If a large proportion of the population is immune to a pathogen, the spread of it is reduced.
Recognised the importance of hand-washing in the prevention of spreading infectious disease.
Insisted doctors washed their hands before examining patients. Greatly reduced number of deaths in the hospital.
Painkillers help relieve symptoms of infectious disease but do not kill the pathogens.
They help cure bacterial disease by killing infectious bacteria. E.g Penicillin
Cannot be used to kill viral pathogens that live and reproduce inside cells.
Important that specific bacteria is treated by specific antibiotics.
Overuse or inappropriate use of antibiotics has increased rate od decvelopment of antibiotic resistint strains of bacteria.
Difficult to develop drugs that kill viruses without damaging the body's tissues.
Strains of bacteria e.g MRSA have developed resistance to antibiotics due to natural selection.
ANTIBIOTIC RESISTANCE =
- Antibiotics kill individual pathogens of the non-resistant strain.
- Individual resistant pathogens survive and reproduce. Population of the resistant strain increases.
- Antibiotics not used to treat non-serious infections such as mild throat infections so the rate of development of resistant strains is slowed down.