When we become sick with a viral disease such as the common cold or the flu, we cannot take medicines to cure it. (Although we may take medicines to relieve the symptoms caused by the virus; such as aspirin to lower a fever.) Antibiotics only kill bacteria not viruses. We have to rely on our immune system to do the work! How does our immune system fight viruses?

Watch this short animation on how our immune system responds to the common cold virus. Pay close attention to the role of the B-Cell and T-Cells.

This activity might not be viewable on your mobile device.Video segment. Assistance may be required.Fighting the Common Cold

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  1. What barriers serve as our body's first line of defense against foreign substances?
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    Skin, Mucus membranes, and MucusClose Pop Up

  2. If a foreign substance, or pathogen, is able to make it through the first line of defense, what is the second line of defense that could eliminate it?
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    macrophagesClose Pop Up

  3. What is the process described in question 2 called?
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    phagocytosisClose Pop Up

  4. If the innate immune response barriers and macrophages do not stop the virus, then _______________ immune response begins.
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    adaptiveClose Pop Up

  5. Each B-Cell, which is a type of white blood cell, has a different _______________ protein.
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    receptorClose Pop Up

  6. When a virus matches a B-cell receptor, what does the B-cell do to the virus?
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    engulfs itClose Pop Up

  7. What do the T-cells signal the B-cells to do?
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    to multiplyClose Pop Up

  8. B-cells become factories that produce ______________ to fight against that particular virus.
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    antibodiesClose Pop Up

  9. Some B-cells become ________________ cells that can rapidly produce antibodies if that particular type of virus invades again.
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    memoryClose Pop Up

As you learned in the "Virus and Cell Lock and Key Activity," viruses attack certain cells. For example, the virus that causes rabies attacks the cell in the brain. HIV, the virus that causes AIDS, attack the very important T-Cells. Watch this video for more information on how HIV attacks the T-cells and why the immune system cannot fight HIV.

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Source: HIV destroys helper T-cells, greatpacificmedia, youtube

Since HIV attacks the T-cells, the T-cells do not signal the B-Cells to divide, making the person infected more susceptible to getting other infections.