CHAPTER 29 Test Your Knowledge
DRIVING QUESTION 1
How is the nervous system organized?
By answering the questions below and studying Infographics 29.2 and 29.5, you should be able to generate an answer for the broader Driving Question above.
KNOW IT
For each of the following, indicate whether it is a part of the CNS or of the PNS.
Light-detecting receptor in the eye______
Amygdala______
Pain receptor in the skin______
Spinal cord______
Thalamus______
Which part of the brain coordinates movement? Which part of the brain maintains body temperature?
Rank the complexity of the cerebrums of the following vertebrates from 1 (most complex) to 4 (least complex).
Bird________
Chimpanzee________
Salamander (an amphibian)________
Fish________
USE IT
Is information flow in the spinal cord one way or two way? Explain your answer.
How does multiple sclerosis cause muscle weakness? Does multiple sclerosis directly affect muscles? Which part of the nervous system is affected?
A brain injury (caused by a blow to the head, for example) that results in the loss of the ability to speak most likely affected the
a. cerebellum.
b. cerebrum.
c. diencephalon.
d. brain stem.
e. hypothalamus.
DRIVING QUESTION 2
How do cells in the nervous system transmit signals?
By answering the questions below and studying Infographics 29.3, 29.4, and 29.6, you should be able to generate an answer for the broader Driving Question above.
KNOW IT
Neurons receive information through their
a. axons.
b. axon terminals.
c. cell bodies.
d. dendrites.
e. nuclei.
Action potentials are a type of________signaling that relies on________.
a. electrical; neurotransmitters
b. electrical; charged ions
c. electrical; electrons
d. chemical; neurotransmitters
e. chemical; charged ions
Neurons release neurotransmitters from their
a. cell bodies.
b. dendrites.
c. axon terminals.
d. all of the above
e. b and c
What happens when a neurotransmitter is released into a synaptic cleft?
Compare and contrast electrical and chemical signaling by neurons.
USE IT
Gatorade and other sports drinks contain replacement electrolytes (ions necessary to enable muscles to continue to contract, especially the ions lost during sweating). Gatorade contains sodium and potassium ions. Other than in the muscle, where else might these ions be crucial during sustained exercise?
Botox is a chemical treatment injected into skin to prevent wrinkling. It is primarily a bacterial toxin that prevents certain neurons from releasing the neurotransmitter acetylcholine. Acetylcholine is normally released by motor neurons to signal muscles to contract. Does Botox paralyze muscles in a relaxed state or a contracted state?
Is more or less of the neurotransmitter acetylcholine released by the axon terminals of neurons in patients with multiple sclerosis compared to those in people who do not have multiple sclerosis? Explain your answer.
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DRIVING QUESTION 3
Why are some drugs (and some behaviors) addictive?
By answering the questions below and studying Infographics 29.1, 29.5, 29.7, and 29.8, you should be able to generate an answer for the broader Driving Question above.
KNOW IT
Addictive substances confer a sense of pleasure because they
a. decrease the amount of dopamine in synaptic clefts.
b. increase the amount of dopamine in synaptic clefts.
c. increase the number of dopamine receptors on the axon terminals of cells that release dopamine.
d. increase the number of dopamine receptors on dendrites of cells that release dopamine.
e. c and d
Why do drug users need to take ever-increasing amounts of drugs to get the same high?
USE IT
Cocaine prevents dopamine from being removed from the synapse. Why does this cause feelings of pleasure?
Would you expect a person born with a relatively low number of dopamine receptors to be happier or sadder than the average? Explain your answer.
MINI CASE
Parkinson disease is caused primarily by a gradual loss of dopamine-producing neurons in the brain. Why is depression often among the debilitating symptoms of Parkinson disease? There are a variety of medications available to treat people with Parkinson disease. Do some internet research to match each medication listed below with its probable mechanism of action.
How can drugs with different mechanisms of action all help treat Parkinson disease? (Hint: What do all the underlying mechanisms have in common in terms of their effect?)
INTERPRETING DATA
Study Infographic 29.8.
a. What are the independent and dependent variables in each experiment?
b. The performances of 14 participants are plotted in each graph. Calculate the average time (in seconds) these participants took to walk the straight line, and the average number of words recalled by these participants.
In the right-hand graph in Infographic 29.8, you will note that there are a few outliers (two are circled in red in the copy of the graph shown below).
c. For the outlier above, is this participant recalling more or fewer words than would be predicted based on his or her availability of dopamine receptors? Explain your answer.
d. For the outlier on the top right, is this participant recalling more or fewer words than would be predicted based on his or her availability of dopamine receptors? Explain your answer.
BRING IT HOME
Replicate the motor skills experiments shown in Infographic 29.8 with some students. On a flat surface, set up a start line and, 10 yards away, a finish line. Instruct each subject to walk in a straight line from the start to the finish and back as fast as they can without running. Start timing when they cross the start line, and stop timing when they cross the start line again at the end of the trial. Have each participant do the trial three times, and record the average of the three trials as the participant’s final time. Now calculate the average time in your set of participants. How does this compare to the 14 methamphetamine users whose performances are plotted in Infographic 29.8?
SOURCE: Method from Robertson, K. R., et al. (2006) Timed gait test: normative data for the assessment of the AIDS dementia complex. Journal of Clinical and Experimental Neuropsychology 28:1053–1064.