fighting disease

• What does the human body have to fight disease?

  A sophisticated defense system
• How does the human body stop pathogens from entering?

  It has features that prevent entry
• What acts as a barrier to pathogens in the human body?

  The skin
• What does the skin secrete to kill pathogens?

  Antimicrobial substances
• What traps particles in your nose?

  Hairs and mucus
• How do cilia help in trapping pathogens?

  They waft mucus to the throat
• What does the stomach produce to kill pathogens?

  Hydrochloric acid
• What can your immune system do when pathogens invade?

  Attack and destroy them
• How do white blood cells travel in the body?

  Through the bloodstream
• What happens when white blood cells encounter invading pathogens?

  They attack and destroy them
• What do white blood cells produce to neutralize pathogens?

  Antibodies
• How do antibodies help the immune system?

  They bind to antigens and neutralize pathogens
• What are the main features of the human body's defense system against disease?

  • Skin acts as a barrier
  • Secretion of antimicrobial substances
  • Hairs and mucus trap particles
  • Cilia waft mucus to throat
  • Stomach produces hydrochloric acid
  • White blood cells attack pathogens
• How does the immune system respond to invading pathogens?

  1. White blood cells travel through blood
  2. They recognize and attack pathogens
  3. They consume pathogens via phagocytosis
  4. They produce antibodies against antigens
• What can white blood cells engulf?

  Foreign cells and digest them
• What is the process called when white blood cells engulf foreign cells?

  Phagocytosis
• What happens when some types of white blood cells encounter foreign antigens?

  They produce proteins called antibodies
• How do antibodies help in fighting infections?

  By locking onto invading cells for destruction
• What is the specificity of antibodies produced by white blood cells?

  They are specific to the type of antigen
• How quickly are antibodies produced after infection?

  Rapidly
• What do antibodies do once produced?

  They circulate to find and neutralize pathogens
• What happens if a person is infected with the same pathogen again?

  They produce antibodies more rapidly
• What are B-lymphocytes known for?

  Producing antibodies
• What do the white blood cells that produce antibodies also known as?

  B-lymphocytes
• What do the toxins produced by invading bacteria do?

  They harm the host's cells
• How do antibodies interact with toxins?

  They neutralize the toxins produced by bacteria
• What should you wear to protect yourself from pathogens?

  Boxing gloves
• What is the role of antibodies in the immune response?

  • Lock onto specific antigens
  • Neutralize toxins
  • Mark pathogens for destruction
  • Prevent pathogen replication
• What are the steps involved in the immune response to a pathogen?

  1. Recognition of foreign antigens
  2. Activation of B-lymphocytes
  3. Production of specific antibodies
  4. Antibodies neutralize pathogens
  5. Memory cells formed for future response