Topic 3 - Infection and Response

• Non-communicable diseases


  Caused by internal factors, e.g. cardiovascular disease, cancer, autoimmune conditions
• Communicable diseases


  Caused by external pathogens, e.g. infections
• Coronary artery


  Delivers blood to the heart muscle to supply oxygen
• Heart attack


  Occurs when coronary arteries are blocked by buildup of fatty deposits, causing coronary heart disease (CHD)
• Stents


  Little tubes inserted into blood vessels to keep them open and allow blood flow
• Statins


  Drugs that reduce cholesterol, which reduces fatty deposits
• Faulty heart valves


  Result in backflow, can be replaced with artificial ones
• Blood


  Carries plasma, red blood cells, white blood cells (combat infections), and platelets (clot wounds)
• Cardiovascular disease (CVD)


  An example of a non-communicable disease, caused by factors within the body
• Examples of non-communicable diseases

  • Cardiovascular disease
  • Autoimmune conditions
  • Cancer
• Communicable disease


  Caused by a pathogen (virus, bacteria, fungus, or parasite) that enters the body
• Carcinogen


  Anything that increases the risk of cancer
• Benign cancer


  Doesn't spread through the body, relatively easy to treat
• Malignant cancer


  Cancerous cells spread through the body, much worse
• Leaves


  Where photosynthesis takes place, producing food for the plant
• Transpiration


  The diffusing of water out of leaves, allowing water and minerals to be drawn up from the roots
• Xylem


  Long continuous tubes that water rises up, unidirectional
• Phloem


  Conveyor belts of cells that transport sugars, food, and sap up and down the plant, bidirectional
• Factors that increase the rate of transpiration

  • Increasing temperature
  • Decreasing humidity
  • Increasing air movement
• Chlorosis


  Yellowing of leaves, due to magnesium deficiency affecting chlorophyll production
• Layers of a leaf

  • Waxy cuticle
  • Upper epidermis
  • Palisade mesophyll
  • Spongy mesophyll
  • Vascular bundle
  • Lower epidermis with stomata
• Stomata


  Holes in the lower epidermis of a leaf, controlled by guard cells to regulate gas exchange
• Communicable disease


  Caused by pathogens (viruses, bacteria, fungi, or protists) that reproduce in the body and cause damage
• Virus


  Protein casing with genetic code that injects into a cell, causing it to produce more copies of the virus
• Vector


  An organism, like a mosquito, that transmits a disease-causing pathogen
• Skin


  First barrier to pathogens entering the body
• White blood cells


  Combat pathogens, including lymphocytes that produce antibodies and phagocytes that ingest and destroy pathogens
• Antigen


  Specific shape on a pathogen that an antibody can bind to and neutralize
• Immunity


  Ability to resist infection by a pathogen, gained by producing antibodies after exposure
• Vaccine


  Dead or inert version of a pathogen that exposes the immune system to produce antibodies without causing infection
• mRNA vaccine


  Injects mRNA to trick cells into synthesizing part of a pathogen, including the antigen
• Antibiotics


  Kill bacteria, but not viruses
• Antibiotic resistance


  Bacteria mutate and become resistant to antibiotics, reducing their effectiveness
• Drug development


  1. Lab trials on cells/tissue

  2. Animal trials

  3. Human trials (blind and double-blind)
• Monoclonal antibodies


  Antibodies made from clones of a cell that produces a specific antibody