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IMMUNE SYSTEM:
The Body’s Defenses – Section 9
Teacher notes
Word Attack
Pathogens
Inflammatory response
Phagocyte
Immune system
lymphocytes
antigens
antibodies
barriers
Vocabulary
1. Barriers like your skin keep pathogens from getting into your body. Pathogens cause
disease.
2. If pathogens get past the barrier of your skin, the inflammatory response helps attack
the pathogens. It is called the body’s general defense.
3. A white blood cell that surrounds the pathogen and destroys it is called a phagocyte.
4. If the inflammatory response is not enough to overcome the pathogen, the next way
your body fights disease is with the immune system.
5. White blood cells called lymphocytes are part of the immune system.
6. Antigens are part of your cells that the immune system recognizes as being a normal
part of you or being from another source outside your body. . It is like the uniform that
helps you determine which team is the home team and which team is the team from far
away.
7. Antibodies latch on to antigens like a jigsaw puzzle piece an mark it for destruction.
Fill in the blanks
1. Your skin creates a ____barrier__________ that keeps dirt and germs out of your body.
2. Another word for a germ that causes disease is a ______pathogen________________.
3. There are 2 types of white blood cells that help fight disease. The kind that surrounds
and destroys it is called a __________phagocyte______________. T cells and B cells in
the immune system are white blood cells called _________lymphocyte___________.
4. The ‘uniform’ on cells that label a cell as being friendly to your body or foreign to your
body are called __________antigen_______.
5. ____Antibodies_______________ are chemicals that lock onto antigens and label it for
destruction.
Barriers
first line of defense
1. Skin – sweat, oil, dead skin cells
2. Breathing passages – cough and sneeze
3. Mouth and stomach – saliva and stomach acid
General defenses
second line of defense
inflammatory response
Latin root “to set on fire”
Swelling, warm to touch
May have a fever
Phagocytes
WBC that engulfs pathogens
Immune System
third line of defense
Specific response to a specific pathogen
Lymphocytes – another type of WBC
T cells – identify pathogen
Antigen – uniform of the pathogen
B cells – produce chemicals to destroy pathogens
Antibodies – chemicals that lock onto antigens
AIDS – acquired immunodeficiency syndrome
Virus that attacks the immune system
People may have virus for years before they become sick
Not spread through shaking hands, hugging
Is spread through
Blood
Infected paraphernalia of drug users
Infected blood transfusions
Sexually transmitted disease
Infected mother to baby during pregnancy