First line
This giant organ acts as the very first barrier pathogens encounter, using oil, sweat, and shedding dead cells to destroy invaders.
Answer: What is the skin?
$100: Triggered when pathogens break through the first line, this response system uses white blood cells to attack invaders.
Answer: What is the inflammatory response system?
$100: The primary goal of your immune system is to eliminate pathogens and maintain this state of internal balance.
Answer: What is homeostasis?
$100: This is the body system designed as a personal army to eliminate pathogens and keep you healthy.
Answer: What is the immune system?
$100: Washing your hands regularly removes invaders because dead skin cells naturally fall off and carry these away.
Answer: What are pathogens?
$200: When trapped pathogens irritate your respiratory system, your body forcefully expels them using these two actions.
Answer: What are sneezing and coughing?
$200: These specific white blood cells surround, take over, and completely destroy pathogens during the second line of defense.
Answer: What are phagocytes?
$200: The third line of defense relies on these two specialized types of lymphocytes.
Answer: What are T cells and B cells?
$200: The immune system works 24/7 to maintain this state of steady internal balance in your body.
Answer: What is homeostasis?
$200: These special white blood cells in the second line of defense stop invaders by surrounding, taking over, and completely breaking them down.
Answer: What are phagocytes?
These three components inside your nose, trachea, and breathing passages trap pathogens before they reach your lungs.
Answer: What are hairs, mucus, and cilia?
$300: Blood vessels widen to increase blood flow to infected areas, causing this bodily response that warms your body to kill off pathogens.
Answer: What is a fever?
$300: Lymphocytes create these targeted molecules, which attach to antigens on a pathogen's surface.
Answer: What are antibodies?
$300: The immune system uses this exact number of defense layers working like soldiers in a war.
Answer: What is three?
$300: In the mouth, this bodily fluid contains special chemicals that actively break down pathogens in your food.
Answer: What is saliva?
$400: Found in the mouth and stomach, these two substances use chemicals and powerful acids to break down food-borne invaders.
Answer: What are saliva and stomach acids?
During a second line response, this change occurs in the blood vessels near the infected area to increase blood flow.
Answer: What is widening (or dilating)?
$400: Pathogens are destroyed when antibodies bind to antigens and trigger this physical process.
Answer: What is clumping?
$400: Any invading organisms or illnesses that enter the body and trigger an immune system response go by this general term.
Answer: What are pathogens?
$400: These targeted molecules stop pathogens by binding to their antigens and causing them to clump together for destruction.
Answer: What are antibodies?