Nervous Systems

Which division of the autonomic nervous system would likely if a student learned that an exam she had forgotten about would activate start in 5 minutes? Explain your answer

Suppose a person had an accident that severed a small nerve required to move some of the fingers of the right hand. Would you also expect an effect on sensation from those fingers?

Most tissues regulated by the autonomic nervous system receive both sympathetic and para sympathetic input from postganglionic neurons. Responses are typically local. In contrast, the adrenal medulla receives input only from the sympathetic division and only from preganglionic neurons, yet responses are observed throughout the body. Explain why (see Figure 45.19).

In a controlled experiment, researchers manipulate one variable at a time. What was the variable manipulated in this study? Why did the researchers use more than one hamster for each procedure? What traits of the individual hamsters would likely have been held constant among the treatment groups?

For the wild-type hamsters that received 𝛕 SCN transplants, what would have been an appropriate experimental control?

What general trends does the graph above reveal about the circadian cycle period of the transplant recipients? Do the trends differ for the wild-type and 𝛕 recipients? Based on these data, what can you conclude about the role of the SCN in determining the period of the circadian rhythm?

In 20% of the hamsters, there was no restoration of rhythmic activity following the SCN transplant. What are some possible reasons for this finding? Do you think you can be confident of your conclusion about the role of the SCN based on data from 80% of the hamsters?

When you wave your right hand, what part of your brain initiates the action?

People who are inebriated have difficulty touching their nose with their eyes closed. Which brain region does this observation indicate is one of those impaired by alcohol?

Suppose you examine two groups of individuals with CNS damage. In one group, the damage has resulted in a coma (a prolonged state of unconsciousness). In the other group, it has caused paralysis (a loss of skeletal muscle function throughout the body). Relative to the position of the midbrain and pons, where is the likely site of damage in each group? Explain.

If a woman with a severed corpus callosum viewed a photograph of a familiar face, first in her left field of vision and then in her right field, why would she find it difficult to put a name to the face?

How can studying individuals with damage to a particular brain region provide insight into the normal function of that region?

How do the functions of Broca’s area and Wernicke’s area each relate to the activity of the surrounding cortex?

Outline two mechanisms by which information flow between two neurons in an adult can increase.

Individuals with localized brain damage have been very useful in the study of many brain functions. Why is this unlikely to be true for consciousness?

Suppose that a person with damage to the hippocampus is unable to acquire new long-term memories. Why might the acquisition of short-term memories also be impaired?

What is the likelihood of a person developing schizophrenia if the disorder affects his or her fraternal twin? How would the likelihood change if DNA sequencing revealed that the twins shared the genetic variants that contribute to the disorder?

Compare Alzheimer’s disease and Parkinson’s disease.

How is dopamine activity related to schizophrenia, drug addiction, and Parkinson’s disease?

If you could detect early-stage Alzheimer’s disease, would you expect to see brain changes that were similar to, although less extensive than, those seen inpatients who have died of this disease? Explain.

Activation of the parasympathetic branch of theautonomic nervous system

(A) increases heart rate.

(B) enhances digestion.

(C) triggers release of epinephrine.

(D) causes the conversion of glycogen to glucose.

Which of the following structures or regions is incorrectly paired with its function?

(A) limbic system—motor control of speech

(B) medulla oblongata—homeostatic control

(C) cerebellum—coordination of movement and balance

(D) amygdala—emotional memory

Patients with damage to Wernicke’s area have difficulty

(A) coordinating limb movement.

(B) generating speech.

(C) recognizing faces.

(D) understanding language.

The cerebral cortex does not play a major role in

(A) short-term memory.

(B) long-term memory.

(C) circadian rhythm.

(D) breathholding.

After suffering a stroke, a patient can see objects anywhere in front of him but pays attention only to objects in his right field of vision. When asked to describe these objects, he has difficulty judging their size and distance. What part of the brain was likely damaged by the stroke?

(A) the left frontal lobe

(B) the right frontal lobe

(C) the right parietal lobe

(D) the corpus callosum

Injury localized to the hypothalamus would most likely disrupt

(A) regulation of body temperature.

(B) short-term memory.

(C) executive functions, such as decision making.

(D) sorting of sensory information.

The reflex that pulls your hand away when you prick your finger on a sharp object relies on a neuronal circuit with two synapses in the spinal cord. (a) Using a circle to represent a cross section of the spinal cord, draw the circuit. Label the types of neurons, the direction of information flow in each, and the locations of synapses. (b) Draw a simple diagram of the brain indicating where pain would eventually be perceived. 

Scientists often use measures of “higher-order thinking” to assess intelligence in other animals. For example, birds are judged to have sophisticated thought processes because they can use tools and make use of abstract concepts. Identify problems you see in defining intelligence in these ways.

Consider an individual who had been fluent in American Sign Language before suffering an injury to his left cerebral hemisphere. After the injury, he could still understand that sign language but could not readily generate sign language that represented his thoughts. Propose two hypotheses that could explain this finding. How might you distinguish between them?

With increasingly sophisticated methods for scanning brain activity, scientists are developing the ability to detect an individual’s particular emotions and thought processes from outside the body. What benefits and problems do you envision when such technology becomes readily available? Explain.

In a short essay (100–150 words), explain how specification of the adult nervous system by the genome is incomplete.

Imagine you are standing at a microphone in front of a crowd. Checking your notes, you begin speaking. Using the information in this chapter, describe the series of events in particular regions of the brain that enabled you to say the very first word.