most people eat a varied diet which includes
everything needed to keep your body healthy
different people need different amount of energy
the metabolic rate varies from person to person
metabolic rate refers to the chemical reaction in you cells
the more exercise you take the more food you need
Weight problems
if you take in more energy you need it will be stored as excess fat
obese people have more health problems than others
people that do not eat enough
can also develop serious
health problems
exercise helps reduce weight
and to maintain health
inheritance, exercise and health
inherited factors affect out health.
these include our metabolic rate and
cholesterol levels
people who exercise are usually much
healthier then people who don't
Pathogens and disease
infectious diseases are caused by
microorganisms called pathogens, such as
bacteria and viruses
bacteria and viruses reproduce rapidly
inside your body. bacteria can produce
toxins which make you ill
viruses damage your cells as they produce. this can also make us feel ill
semmelweis recognised the importance of
washing your hands in hospitals because that
prevented the spreading of disease
Defence mechanisms
your body has several methods of defending itself against
the entry of pathogens using skin, the mucus of the
breathing system and the clotting of the blood
your white blood cells help you defend against pathogens
trying to enter the body. this happens by white blood cells
ingesting them and making antibodies and antitoxins
using drugs to treat disease
some medicines relive the symptons of the disease but not kill the disease which caused it
antibiotics cure bacterial by disease killing the bacteria in your body
antibiotics do not destroy viruses
because viruses reproduce inside the
cells. it is difficult to develop drugs that
can not be destroy viruses without
damaging your body cells
growing and investigating bacteria
an uncontaminated culture of microorganism can be grown using
sterilised petri dishes and agar. you sterilise the inoculation loop
before use and seal lid of petri dish to prevent unwanted
microorganism getting in
changing pathogens
many types of bacterium have developed antibiotic
resistance as a result of natural selection. to prevent the
problem getting worse we must not overuse antibiotics
if bacteria or viruses mutate, new strains of the pathogens can
appear causing disease
new strains of disease which spread rapidly can cause
epidemics and pandemics. antibiotics and vaccinations may not
be effective against the new strain
immunity
your white blood cells produce
antibodies to destroy the pathogens.
then your body will respond rapidly to
future infections by the same
pathogen, by making the correct
antibody. you become immune to the
disease
we can use vaccinations to
protect against both bacterial
and viral pathogens
you can be immunised against disease by
introducing small amounts of dead or inactive
pathogens into your body
how to deal with disease
vaccinations
protects
individuals and
society from the
effects of a
disease
the treatment of
disease has changed
as our understanding
of how antibiotics
and immunity has
increased