Health and Disease

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Cards (181)

  • health-> “A state of complete physical, mental and social well-being and not merely the absence of disease or infirmity.
  • Communicable diseases-> transferred between individuals. caused by pathogens (virus, bacteria, fungi)
  • pathogens-> micro-organisms that causes diseases
  • communicable caused by pathogens
  • pathogens can enter by:
    • breathed in through mouth and nose
    • ingested in water or food
    • through cuts or bites
    • natural openings
  • bacteria: living cells that produce toxins and reproduce quickly (live in blood, killed by antibiotics)
  • fungi: produce spores and penetrate on human skins
  • virus: lives and reproduce quickly inside our cells, causes cell damage
  • protists: eukaryotic cells that can spread through vectors (has nucleus)
  • non-communicable: cannot be passed on
  • Often, the presence of one disease can lead to increased susceptibility to other diseases. For example:
    • Having HIV means that your immune system is impaired, leaving you at risk to many other ‘opportunistic’ infections, caused by bacteria, viruses and fungi.
    • Having a particular virus called HPV can increase a woman’s risk of developing cervical cancer.
  • pathogen is an organism which causes disease
  • our bodies have defence mechanisms against invading micro-organisms
  • chemical barriers against invading microbes:
    • enzymes in the tears kill bacteria on the surface of our eyes
    • stomach contains hydrochloric acid, kills bacteria and 'friendly' bacteria that kills microbes
  • physical barriers against invading microbes:
    • breathing organs have hairs and produce mucus to cover lining of these organs and traps pathogens
    • hair and mucus in nose traps particles that could contain pathogens
    • skin acts ass waterproof barriers
  • if microbes enter the body, they need to be neutralised or killed. done by white blood cells
  • some white blood cells (phagocytes) ingest the microbe
  • some lymphocytes release anti bodies which attach to the pathogens and either destroy them or cause them to stick together
  • antibodies are specific to a pathogen
  • antibodies: made by lymphocytes
  • producing antibodies:
    • white blood cells sees the pathogens (microbes)
    • cells produce antibodies to 'fit' the antigen
    • antibodies fit onto the antigens and cause the pathogens to 'clump'
    • pathogens ingested by the phagocytes
  • some lymphocytes turn into memory cells. these can quickly kill anti bodies because they already have made an antibody for this before.
  • waist:hip ratio better measure of obesity because muscle mass can affect BMI
  • Option 1: lifestyle changes
    • moderate excercise
    • balanced diet
    • avoid smoking
    Option 2: lifelong med
    • anti hypertensive (reduce blood pressure)
    • statins (reduce cholestrol)
    Option 3: surgical procedures
    • bipass surgery
    • stent
    • transplant
  • Vaccine
    Exposes the body to weakened or inactivated pathogens, allowing the immune system to develop immunity without catching the full disease
  • Vaccines
    • Contain weakened or inactivated pathogens that the body recognizes and responds to by producing antibodies, developing immunity
    • Available for many diseases, including both bacteria and viruses
    • Given to children before primary school to protect against over a dozen potentially deadly diseases
  • Vaccines generally outweigh their cons
  • Antibiotics can only be used to treat bacterial infections, and not those caused by viruses, fungi or other pathogens. Bacteria are susceptible to antibiotics because antibiotics inhibit cell processes in the bacterium. However, viruses and other pathogens often use cell machinery in host cells to reproduce, and these are unaffected by antibiotics.
  • By immunising a large proportion of the population, the spread of the pathogen is reduced as there are less people to catch the disease from (called herd immunity).