Nervous System Case Study 4*


Sarah, a twenty-one year old student at Iowa State University had spent Thanksgiving Day with relatives at her grandparent’s farm. During her drive back to campus on Friday morning her vision became blurry, and she was forced to pull over to the side of the road. As she sat in her car, her vision worsened.  Later Sarah was rushed to the emergency room of a nearby hospital.


In the ER, Sarah was able to describe her symptoms to a physician. The physician made note of what Sarah had eaten during the last 24 hours and was especially interested in the fact that Sarah’s grandmother canned all of her own vegetables. The physician observed that Sarah’s breathing was becoming labored. The doctor ordered Sarah’s blood sampled, her gastrointestinal tract pumped, and a mechanical respirator prepared for use.  The doctor suspected food poisoning, a possible case of botulism.  She asked that Sarah’s grandparents be contacted and samples of the Thanksgiving meal retained, if possible, and sent to a local clinic for analysis.


Botulism is caused by exposure to a toxin called botulin. Botulin is produced by Clostridium botulinum, a spore forming, anaerobic bacterium that can contaminate food. Whereas commercially canned foods are specifically heated to destroy botulinum spores, home canned foods that are not boiled for a half-hour prior to canning may be contaminated.




1.Why is there electrical activity in the brain? Describe how a nerve impulse is transmitted from one neuron to the next.


2. Compare and contrast the structure and functions of the Central Nervous System and the Peripheral Nervous System.


3. What is myelin? What is its function?  Explain.

4. What two organ systems are primarily affected by botulin intoxication? Describe the effect of the botulin toxin on the body.

5. List the normal sequence of events that occur during synaptic transmission at a motor end plate.

6. What were Sarah’s symptoms and how do they relate to the blockage of acetylcholine release from motor neuron synaptic terminals?

7. What is the significance of Clostridium botulinum being anaerobic?

8. Why didn’t the physician prescribe an antibiotic?


*adapted from McGraw Hill Online Learning Center, Essentials of Anatomy and Physiology,3rd ed.Seely/Stephens/Tate