The Body's Defenses Against Germs by hcj


									The Body’s Defenses Against Germs

Mark your correct answers with a star or a smiley or a “c”. Write
in the corrections for any incorrect answers. You must you a RED
pen to receive credit for corrections.
   1. What is an infectious disease?
   An infectious disease is any disease caused by an agent or pathogen that invades the
   body; a disease that you can “catch”.
   2. What are ways that are infections normally spread between people? Infections are
       normally spread between people by touching or by sharing foods/drinks. They
       may also be spread when germ filled droplets (from a cough or sneeze) are
       inhaled by another person (ooh, yucky!)
   3. What does an antibiotic do? An antibiotic is a drug that kills bacteria or slows the
       growth of bacteria.
   4. What are viruses? Viruses are tiny, disease-causing particles that consist of genetic
       material and a protein coat. They can invade a healthy cell and instruct that cell
       to make more viruses.
   5. List some symptoms of a viral infection. Some symptoms of a viral infection are
       nasal congestion, a sore throat, body aches, and fever.
   6. List 6 physical barriers that your body’s defense system uses to keep germs from
       getting into your body. 6 physical barriers in our immune system are: skin, hairs,
       tears, mucus, saliva and stomach acid.
   7. What are three symptoms of a sinus infection? Symptoms of a sinus infection are
       congestion, runny nose, fever, or headache.
   8. How can you protect yourself from getting infections? You can protect yourself
       from getting infections by staying away from people who have a contagious
       disease, by washing your hands regularly with soap and warm water, by not
       sharing drinks/food, by keeping your immune system strong through eating a
       balanced diet, exercizing and getting enough sleep.
   9. How can you protect others from getting infections? You can protect others from
       infection by washing hands regularly, by covering your mouth and nose when
       sneezing using your elbow, and by staying away from others when you are sick.
   10. Identify five of the early childhood vaccinations currently available. Early
       childhood vaccinations currently available are hepatitis, measles, mumps, rubella,
       polio, diptheria, tetanus, pertussis and chickenpox.
   11. Why do you think a person might get a slight fever or rash after receiving a
       vaccination? When a person receives a vaccine, she/he is getting a weakened
       germ, so her/his body responds to this by producing antibodies that will fight off
       this germ in the future. The body’s response can also be a fever or a rash (to a
       much lesser degree than a true infection would cause!)

   12. Define;
         a. Immunity is a body’s ability to resist an infection or to easily fight off an
           b. Barrier is a blockage to invading organisms.
           c. Mucus is the sticky liquid substance in your nose, throat and other similar
              membranes in your body. It traps germs, and contains enzymes that attack
              and destroy germs.
           d. The immune system is a combination of the physical and chemical
              defenses that your body has to fight infection; the tissues, organs and cells
              that fight pathogens.
           e. Macrophage means “big eater”, this is a large white blood cell that engulfs
              viruses, bacteria and infected cells.
           f. Fever is an elevated body temperature, which, in response to an infection,
              may kill the organisms that are causing the infection. Fever may increase
              the rate at which your body fights infection.
           g. Lymphocytes are special white blood cells (B and T cells).
           h. B-cells are white blood cells that produce antibodies to destroy germs.
           i. T-cells are white blood cells that can directly destroy infected cells and
              that trigger B cells to produce antibodies.
           j. Antibody is a substance produced by B cells that destroy germs, and signal
              other cells to destroy viruses.
           k. Vaccine is a substance that is used to make a person immune to a certain

13. If you are infected with chicken pox virus (varicella) and then get the chicken pox
vaccine, will this help you? Explain. If you are infected with chicken pox virus and
THEN get the chicken pox vaccine, it will not help you. The vaccine stimulates the same
response in your body that the real infection does. You must receive a vaccine BEFORE
being infected with the pathogen if it is to help your body fight the infection.

14. Define for Extra credit (not in your book - look these up in an outside source):
Interferon is a substance made by cells when they are invaded by viruses, it can help the
body fight cancer cells.
An Antigen is a foreign substance that causes the body to have an immune response.
A booster shot is an additional dose of vaccine to ensure that the body maintains
immunity to the disease.

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