Critical and Creative Thinking Questions
1. Multiple sclerosis is a disease that causes destruction of the
myelin sheaths of CNS neurons. Explain the effects of this
disease on the conduction of action potentials.
2. Head trauma suffered in a car accident left Mrs. Anderson
blind, even though she did not injure her eyes. Where on her
head did she suffer trauma, and what part of her brain was
most likely affected?
3. Jack fell off a ladder and injured his back. He could not move
his legs and had no feeling below his waist, but he did respond
to pin pricks from his waist upward. Which spinal cord seg-
ment did he injure in his fall?
4. Julia was startled when her boyfriend sneaked up behind her
and yelled loudly. Her heart was racing, and she was breathing
rapidly. Explain her responses and trace the neural pathways
5. A dentist wishes to numb a patient's upper teeth for a root
canal procedure. Near which cranial nerve should he inject the
What is happening in this picture?
Consuming alcohol slows reflexes, impairs judgment, and
causes drowsiness. Great quantities of y-aminobutyric acid
(GABA), an inhibitor that floods synapses, are released from
certain neurons in the brain when a person drinks.
Explain how G A B A influences
synap tic transm ission to produce the effects associ-
ated with alcohol.
If coffee or caffeine stim ulates the sam e neural
pathw ays as those affected by alcohol, then what
w ould be the effects of excessive caffeine?
What is happening in this picture? 223