B3 - Infection and Response

• Health is a state of physical and mental well-being.
• A disease is any disorder of the structure or function of an organism that is not simply a direct result of physical injury.
• A communicable disease is a disease that can be spread. It is cause by pathogens. An example of a communicable disease is coronavirus.
• A non-communicable disease is a disease that cannot spread. It is non-infectious. An example of a non-communicable disease is cancer.
• Good health is complete mental and physical well-being. It is about feeling good and having a healthy frame of mind. Diseases are disorders that affect part or all of an organism. Diseases cause by infections are communicable diseases. Examples include measles and chicken pox. Diseases not cause by infections are non-communicable. Examples include cancer and CHD.
• Factors that could have a major effect on physical and mental health include:

  • Diet
  • Lifestyle factors such as alcohol and other drugs
  • Stress
• Correlation is the relationship between two sets of data such as that when one set changes you would expect the other set to change as well. Correlation doesn't necessarily mean causation.
• Cancer is the rapid and uncontrolled division of cells.
• Cancer causes tumours.
• Tumours can be malignant (cancerous) or benign (non-cancerous).
• Tumours interfere with the activity of the cells in the tissues of the organs that surround them.
• Benign tumours can compress tissues, preventing normal blood flow or nerve function.
• Benign vs Malignant tumours

  
  

  Benign tumours:

  • Do not spread to other organs.
  • These tumours are not cancerous.
  • Usually contained within a membrane.

  
  

  Malignant tumours:

  • Spread to different organs and form secondary tumours.
  • Invade other organs via the blood.
  • These tumours are cancerous.
• Benign tumours are non-cancerous, while malignant tumours are cancerous.
• Pathogens are microorganisms that cause infectious disease and may be viruses, bacteria, protists or fungi.
• Bacteria may produce poisons (toxins) that damage tissues and make us ill.
• Viruses live and reproduce inside cells, causing cell damage.
• 6 ways a disease can be transmitted:

  1. In the air
  2. By direct contact
  3. Water or Food
  4. Mosquitoes or insects
  5. By animals
  6. By bodily fluids
• An organism that can spread a disease is called a vector.
• Ways you can prevent the spread of communicable diseases:

  • Washing your hands
  • Cooking food properly
  • Isolation
  • Vaccinations
  • Insecticides
  • Access to clean water