immune system

• What is the main function of the human body's defense system?

  To protect against pathogens
• How can the defense system be categorized?

  Into physical, chemical barriers, and immune system
• What acts as a physical barrier in the human body?

  Skin
• What substances does the skin secrete to kill pathogens?

  Oils and antimicrobial substances
• How do pathogens typically enter the body?

  Through holes like the nose or mouth
• What adaptations do noses have to trap pathogens?

  Little hairs and mucus
• What are the two tubes leaving the throat?

  The trachea and esophagus
• What is the role of mucus in the trachea?

  To trap particles and pathogens
• What structures line the trachea to prevent mucus buildup?

  Cilia
• What do cilia do in the respiratory system?

  Move mucus and trapped particles
• What does the stomach produce to kill pathogens?

  Hydrochloric acid
• What is the pH level of stomach contents?

  About 2
• What happens when pathogens enter the body despite defenses?

  The immune system hunts them down
• What is the most important part of the immune system?

  White blood cells
• What is phagocytosis?

  Engulfing pathogens by white blood cells
• What do white blood cells produce to counteract toxins?

  Antitoxins
• What are antigens?

  Foreign substances detected by the immune system
• What are antibodies?

  Proteins made by white blood cells
• How do antibodies function in the immune response?

  They bind to foreign antigens
• What happens when the immune system recognizes a pathogen?

  It produces many specific antibodies quickly
• What does it mean to be immune to a disease?

  The body quickly destroys pathogens upon re-exposure
• What are the components of the human body's defense system?

  • Physical barriers (e.g., skin)
  • Chemical barriers (e.g., stomach acid)
  • Immune system (e.g., white blood cells)
• What are the functions of white blood cells?

  1. Phagocytosis: Engulf pathogens
  2. Produce antitoxins: Counteract toxins
  3. Produce antibodies: Target foreign antigens
• How does the immune system remember pathogens?

  • Produces specific antibodies
  • Remembers the pathogen for future attacks
• What is the main topic of the video?

  How vaccines work
• What happens to our immune system after exposure to a pathogen?

  It develops immunity to that pathogen
• Why do we only catch chickenpox once?

  Because we develop immunity after the first infection
• What is the problem with naturally catching diseases?

  It can range from unpleasant to lethal
• What do vaccines allow us to do?

  Expose ourselves to pathogens without catching diseases
• What do vaccines contain?

  Weakened or inactivated pathogens
• How does the body respond to the weakened pathogens in vaccines?

  By producing antibodies and developing immunity
• How many diseases are we vaccinated against by primary school?

  More than a dozen diseases
• What is the main pro of vaccines?

  They protect us from catching horrible diseases
• What larger effect do vaccines have on disease control?

  They help control common diseases
• What is the purpose of vaccines?

  To expose the body to weakened or inactivated pathogens and develop immunity
• How do vaccines work to provide immunity?

  The weakened pathogens in vaccines trigger the body to produce antibodies and develop immunity
• What is herd immunity?

  When enough people in a population are immune, the pathogen has no one to spread to
• How do vaccines help prevent disease outbreaks or epidemics?

  By creating herd immunity so the pathogen has no one to spread to
• What are some diseases that vaccines have helped control or eliminate?

  Polio, smallpox, measles, and whooping cough
• What are some potential problems with vaccines?

  They don't always provide full immunity and can sometimes cause side effects