immune system

• What is the primary function of the immune system?

  To protect the body from pathogens
• What are the main components of the immune system?

  • White blood cells (neutrophils)
  • Spleen
  • Lymph nodes
• How do white blood cells protect the body?

  By fighting infections and harmful invaders
• What is the role of the spleen in the immune system?

  Removes old red blood cells and stores lymphocytes
• What do lymph nodes do for the immune system?

  Filter out pathogens and activate immune cells
• What is an infection?

  Invasion and growth of pathogens in the body
• What are the types of infections mentioned?

  Viral, bacterial, parasitic, and fungal infections
• What are the different ways pathogens may enter the body?

  1. Direct transmission
  2. Indirect transmission
  3. Airborne transmission
• What is direct transmission of pathogens?

  Physical contact with an infectious person
• How can pathogens spread indirectly?

  Through contaminated water or vectors
• What is airborne transmission?

  Pathogens carried in air, dust, or droplets
• How does skin act as a physical defense?

  Keratin provides waterproof protection
• What is the role of skin flora in defense?

  Outcompete pathogens for surface space
• What do cilia do in the respiratory system?

  Help move debris and keep lungs clear
• How do mucous membranes protect the body?

  Mucus traps pathogens and contains enzymes
• What happens during blood clotting?

  Platelets form a barrier to stop bleeding
• What is inflammation?

  Swelling around a rupture due to immune response
• What role do histamines play in inflammation?

  They dilate blood vessels and increase permeability
• What is the normal body temperature?

  37 degrees Celsius
• How does sebum protect the skin?

  Creates an acidic environment to deter pathogens
• What is the function of lysosomes in tears and saliva?

  Break down bacterial cell walls
• How does stomach acid protect the body?

  Kills most germs by creating an acidic environment
• What role does urine play in defense?

  Flushes out pathogens during urination
• What are the chemical defenses of the body?

  • Oil (sebum) and sweat
  • Tears, saliva, and mucus
  • Stomach acid
  • Urine