Chapter 11- Health and Disease



Physical, mental and social welbeing you are in good health if you are:

Free from disease

Well fed

Well intergrated in society

Have proper sanitation

Have a positive outlook

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A departure from good health - malfunction of the body or mind

  • Causes physical, mental or social problems
  • Diseases caused by living organisms are called INFECTIOUS
  • Normal physical but can effect social and mental wellbeing as well.

Types of disease





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Parasites + Pathogens

Organisms that live on or in a living organism (the host)

  • Can live externaly
  • Can live internaly
  • Causes harm to the host - taking nutrients
  • Can go unnoticed but can cause major issues if thrive in the enviroment = secondary infections


Organisms that cause disease by taking nutrition from their host but cause damage in the process

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  • Anopheles (female mosquitos) are vectors
  • Plasmodium is the most widespread cause of Malaria - eukaryotic organism
  • Anopheles feed on blood - adapted tubes to take in blood from blood vessels
  • If host has Malaria the mosquito sucks the parasite gamates into stomach -develop in to zygotes then move the the salviary glands
  • Mosquito then bites another person and infected salvia is transmitted - gamates then produced in the red blood cells of the infected
  • Plasmodium can be transmitted by unhygenic medical practise, unscreened blood transfusions also can move along the placenta to unborn child.
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  • Caused by the human immodeficiency virus (HIV)
  • Enters the body and remains inactive = HIV positive
  • It attacks and destroys the T helper cells in immune system - meaning ability to resist infection is reduced
  • Unable to defend ourselves from any pathogens- contract infections
  • AIDS - Aquried immune deficiency syndrome - result of HIV

Transmitted by:

  • exchange of body fluids
  • Unprotected sex
  • Unscreened blood transfusions
  • Unstyrlised medical equipment
  • Hypodermic needles
  • Breast feeding
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Tuberculosis (TB)

  • Caused by mycobacterium tuberculosis and M.bovis
  • Usally found in the lungs

Spread by:

  • Overcrowding
  • Poor ventiliation
  • Poor health
  • Homelessness
  • Poor diet
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