health and disease

• communicable diseases - can be passed between people
• spread through

  • air
  • contaminated water
  • contaminated food
  • direct contact
  • bodily fluids
• virus - infectious agent / can only replicate inside the living cells of an organism
• HIV

  • weakens immune system - destroys white blood cells
  • spread by - sexual contact / exchange of bodily fluids
• Ebola

  • fever / headache / muscle pain
  • spread through direct contact / bodily fluid
• plant diseases - causes

  • infection by microorganisms
  • attack by larger organisms
  • lack of essential minerals
• symptoms

  • stunted growth
  • spots on leave
  • areas of decay
  • growth
  • malformed stems / leaves
  • discolouration
• physical defences

  • strong cellulose cell walls
  • layer of bark
  • waxy cuticle on stem / leaves
• identify

  • compare symptoms to a manual / website
  • take to a laboratory
  • testing kits containing monoclonial antibodies
  • test DNA of pathogens
  • use rial / error to test for different treatments
• chemical defences

  • antimicrobal substances
  • poissions that kill insects
• mechanical defences

  • hair / thorns
  • leaves curl / droop when insects land
• non specific human defence

  • skin
  • stomach acid
  • tears in eyes
  • hair / mucus in airways
• immune system - locate / destroy pathogens

  • phagocytes
  • lymphocytes
  • produce antibodies
  • produce antitoxins
• antigen - substance your body sees as forigen
• antibody - protein produced by white blood cells
• vaccination

  • contains weakened / inactive pathogen
  • lymphocytes produce antibodies to combat pathogens
  • if the body is infected again memory lymphocytes act very quickly to kill pathogen
  • no symptoms are shown
• monoclonal antibodies

  • inject animal with antigen
  • develop immune response
  • collect B-lymphocytes
  • combine them with cancer cells (mylema cells)
  • creates hybridoma cells
  • they divide quickly by mitosis in a petri dish
  • collect monoclonal antibodies
• uses of monoclonal antibodies

  • diagnosis
  • treat diseases
  • detect pathogens
  • measure hormone levels (pregnancy tests)
• developing new medicines

  • test on human cells / tissues
  • test on live animals
  • test on healthy volunteers
  • test on diseased patients - double blind
• placebo - looks like a real treatment but contains no active drug
• double blind - doctors and patients both don't know who has the real treatment

  • avoids bias
  • more likely to have valid results
  • monitor everyone's symptoms equally
• risk factors for disease

  • genetics
  • lifestyle choices

  poor diet

  lack of sleep

  too much stress

  smoking

  drinking alcohol

  lack of exercise
• obesity

  • lack of exercise
  • lots of sugar / fats

  BMI = mass / $\left(height\right)^2$
• cardiovascular system

  • heart
  • blood
  • blood vessels
• coronary heart disease

  • layers of fatty material builds up inside coronary artery
  • becomes narrower
  • reduces blood flow
  • lack of oxygen for heart muscle
• coronary heart disease - treatments - stent

  • keeps arteries open
  • allows more blood flow
  • surgery is quick
  • lasts a long time
  • almost immediate effect
• coronary heart disease - treatments - statins

  • reduce LDL cholestrol / increase HDL cholestrol in blood
  • taken everyday
  • side effects - kidney failure / headaches
  • can take months to work
• faulty heart valves

  • not enough blood can pass through
  • blood can pass backwards through the valves
• replacement valves

  • biological - pigs / cows
  • mechanical - metal
• heart failure - unable to pump blood around the body

  • replace heart
  • medications
• biological hearts can be rejected - can be seen as foreign so attacked by immune system