preventing and treating diseases

• What are non-specific defenses of the body against pathogens?

  Defenses that protect against all pathogens
• What are the functions of the skin in non-specific defenses?

  • Physical barrier to infection
  • Produces antimicrobial secretion
  • Hosts microorganisms that prevent pathogen growth
• What role do cilia and mucus play in the nose?

  They trap particles preventing lung entry
• How do the trachea and bronchi contribute to non-specific defenses?

  They produce mucus moved away from lungs
• What does the stomach produce to destroy pathogens?

  Strong acid with a pH of 2
• What is the primary function of white blood cells?

  To fight pathogens entering the body
• What are the two main types of white blood cells?

  • Lymphocytes
  • Phagocytes
• How do lymphocytes neutralize toxins?

  By producing antitoxins that bind to toxins
• What do lymphocytes produce to target specific pathogens?

  Antibodies that bind to antigens
• What are the steps phagocytes take to destroy pathogens?

  1. Attracted to infection areas
  2. Surround and engulf the pathogen
  3. Release enzymes to digest the pathogen
• What are antibiotics used for?

  To kill bacteria in the body
• Why must specific bacteria be treated with specific antibiotics?

  Because different antibiotics target different bacteria
• What is a consequence of antibiotic use?

  Emergence of antibiotic-resistant bacteria
• Do antibiotics affect viruses?

  No, they do not affect viruses
• What is a risk of drugs that kill viruses?

  They often damage the body’s tissues
• What do painkillers do for viral diseases?

  Treat symptoms but do not kill pathogens
• How were drugs traditionally discovered?

  • Extracted from plants and microorganisms
  • Example: Digitalis from foxglove
  • Example: Aspirin from willow trees
  • Example: Penicillin from Penicillium mould
• How are most modern drugs created?

  They are synthesized by chemists in labs
• What are the three key tests for new drugs?

  • Toxicity: Is it harmful?
  • Efficacy: Does it work?
  • Dose: What amount is safe and effective?
• What are the stages of clinical trials?

  1. Pre-clinical trials: Tested in cells, tissues, animals
  2. Clinical trials:

  • Low doses to healthy volunteers
  • Larger groups for optimum dose
• What is the purpose of peer review in drug trials?

  To check results by independent researchers
• What is a double-blind trial?

  Neither patients nor doctors know treatment
• Why are placebos used in clinical trials?

  To reduce biases in the trial results