B2 Health matters and cancer

• Health is a state of physical and mental wellbeing
• What factors affect physical and mental health?

  Diet, stress, drugs, genes, excercise
• What are communicable diseases?


  Can spread because they are created by microbes
• What are non-communicable diseases?


  Cannot spread because thye are NOT caused by microbes
• What is a risk factor?


  A variable that increases the likelihood of a particular disease but does not guarantee the person will develop it
• Scientists analyse data to see if there is a relationship between risk factors and particular diseases. We call this relationship a correlation
• Two variables can be correlated without causing the other
• What is a casual mechanism?


  Way in which something increases the risk of a disease
• The human and financial costs of ill health are extensive, for example : Poor physical health increases the likelihood of poor mental health

  Cost of treatment is increasing

  Financial impact on families due to ill health
• Having one disease increases the likelihood of developing another
• Defects in the immune system (HIV) increases likelihood of other communicable diseases eg. colds
• Viral infections (HPV - can damage cervix in women) increases likelihood of cervical cancer in women
• Immune response to pathogens(white blood cells responding to other substances incorrectly) can cause allergic reactions
• Why are new cells needed?

  Growth

  Repair to damaged tissue or replace dead cells
• The process of creating new cells is usually carefully controlled to make sure the right number and right type of cells are amde at the right time
• How are new cells made?


  The DNA is copied inside an existing cell and the cell divides so there are two cells
• What is a mutation?


  Mistake made when the DNA is copied
• What is a tumour?


  When a cell has lots of mutations which enables it to grow and divide in an uncontrolled manner, producing too many new cells
• How can the chance of mutations be increased?


  Smoking

  UV radiation

  X-Rays
• What is a benign tumour?


  Cells that are contained with one area inside a membrane. Cells do not invade other parts of the body and it is not cancerous
• What is a malignant tumour?


  Cells that are not within a membrane.Cells break off and spread to other parts pf the body via the blood. These tumours are cancerous