-non-communicable diseases

• Diabetes

  A group of disorders where blood glucose cannot be properly regulated by the body, which is potentially very dangerous
• Types of diabetes

  • Type 1
  • Type 2
• Type 1 diabetes

  Caused by a defect in the pancreas, where the cells that produce insulin don't work
• Type 2 diabetes

  There is no problem with the pancreas - it produces insulin as usual, but body cells no longer respond to the insulin
• Treatment for type 1 diabetes

  Injections of insulin produced by genetically engineered bacteria
• Treatment for type 2 diabetes

  Carbohydrate-controlled diet and exercise (insulin injections have no effect)
• Obesity is a major risk factor for type 2 diabetes, and there is also a genetic risk factor
• Dialysis

  Treatment for kidney failure, in which a machine filters toxic substances from the blood instead of the kidneys
• Immunosuppressant

  Type of drug that reduces the responses of the immune system, to prevent rejection of a transplanted kidney
• Kidney failure

  If the kidneys fail, it is extremely dangerous. Can be treated by kidney transplant or dialysis
• How dialysis machine works

  Large surface area to increase rate of diffusion of urea out of the bloodstream
• Coronary heart disease

  Narrowing of the coronary arteries due to build-up of fatty material, reducing blood flow to the heart muscle
• Stent

  Mesh or cage-like structure that keeps coronary arteries open so blood can flow through
• Statins

  Medicinal drugs used to lower blood cholesterol, a risk factor for coronary heart disease
• Heart valve problems

  Valve may get a leak, or might not open fully, affecting blood flow
• Replacement heart valves

  Can be biological (from a living organism) or mechanical (synthetic)
• Heart failure

  Where the heart cannot pump blood around the body properly
• Heart and lungs can be transplanted together if required
• Artificial hearts can be used to keep someone alive while they wait for a heart transplant
• Communicable diseases

  Also called infectious diseases, they always result from an infection by a pathogen
• Organisms that can be infected by pathogens

  • Plants
  • Bacteria
  • All organisms
• Bacteria cause disease

  They reproduce rapidly and can release poisonous chemicals (toxins) that damage cells
• Diseases caused by pathogenic bacteria

  • Cholera
  • Tuberculosis (TB)
  • Food poisoning
• Viruses cause disease

  They reproduce inside cells and burst the cell from the inside, releasing more viruses to infect other cells or people
• Fungi cause disease

  By growing on living tissue (e.g. athlete's foot)
• Protists cause disease

  They can live in host organisms (e.g. malaria protist)
• Methods of pathogen transmission

  • Direct contact
  • Sexual contact
  • Mother to foetus
  • Vector (animal)
  • Droplet infection
  • Waterborne
• We can attempt to reduce the transmission of pathogens by: vaccinating people; destroying vectors; being hygienic; isolating infected people
• Cancer

  A non-communicable disease involving uncontrolled cell growth and division
• Benign tumours

  • Growths of abnormal cells, but do not invade other parts of the body
  • Often surrounded by a membrane
• Malignant tumours

  • Cells grow out of control and invade nearby tissues
  • Mutated cells can break off and spread to cause secondary tumours
• Some risk factors for cancer are very clearly identified, like smoking for lung cancer

  
• There can be genetic risk factors for some types of cancer
• Mutation

  Change to DNA, altering its function (not necessarily dangerous). In cancer, a specific mutation causes uncontrolled cell division
• Protist

  Whole kingdom of organisms, including some that cause disease
• Transmission

  The passing of a pathogen from one organism to another, leading to the spread of communicable (infectious) disease
• Host

  The organism that a pathogen lives in or on
• Health is the state of physical and mental wellbeing
• Diseases are major causes of ill-health
• Factors affecting health

  • Diet
  • Lifestyle
  • Stress
  • Genetic inheritance