18.2 Chapter 2: Biology and Behavior

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1. b. the human nervous system
2. neuroscience
3. Answers will vary. Building blocks can include items ranging from flour and butter in culinary training to numbers in mathematics. Atoms, chemical compounds, mechanical parts, and many other basic components may be building blocks in other fields of study.

1. myelin sheath
2. a. glial cells
3. b. Neurotransmitters; synaptic gap
4. A diagram could include the following information: Neural communication involves different processes within and between neurons. Using Infographic 2.1, you can follow the electrical action within the neuron. Messages received by the dendrites from neighboring neurons are passed along the axon, which sends messages to other neurons through its branchlike terminal buds.
   Infographic 2.2 demonstrates how neurons communicate with each other via chemicals called neurotransmitters. The signal to release neurotransmitters is the voltage change from the action potential, which results in vesicles that contain neurotransmitters attaching to the membrane on the terminal bud. This allows the neurotransmitter to be released into the synaptic gap. The majority of these neurotransmitters drift across the synaptic gap and come into contact with receptor sites of the receiving neuron’s dendrites, which may (or may not) lead to an action potential in the receiving neuron.

1. d. Motor neurons
2. b. spinal cord
3. pituitary
4. Both types of responses tend to increase the likelihood of survival and reproduction. The flight-or-flight strategy centers on self-preservation: by confronting or fleeing a threating situation, the individual is acting to ensure her own survival and ability to reproduce. Tend and befriend is perhaps a less direct approach. Forging social bonds and tending to the young strengthen the community as a whole, which can support the survival and reproduction of its members.

1. d. lateralization.
2. b. Broca’s area.
3. split-brain operation
4. The corpus callosum is a bundle of nerve fibers that allows the two halves of the brain to communicate and work together to process information. This same band of nerve fibers can also serve as a passageway for electrical storms responsible for seizures. With the split-brain operation, the corpus callosum is severed so that these storms can no longer pass freely between the hemispheres.

1. c. neurogenesis
2. Independent variable: manipulation of hearing classical music.
   Dependent variable: measure of cognitive abilities.
   Answers will vary. The experimental group would listen to classical music and the control group would not listen to classical music.
3. Stem cells
4. a. neuroplasticity

1. b. frontal lobes
2. association areas
3. Answers will vary. There is no right or wrong mnemonic; use one that will help you remember.
   Here is one example connecting letters or word segments to function:
   Frontal lobes: Front and center (integrating information from all over the brain)
   Occipital lobes: “Oh, did you see that?” (visual processing)
   Parietal lobes: Perceive touch (processing of touch sensations)
   Temporal lobes: Tempo is just right (auditory processing)
4. c. damage to his frontal lobes

1. b. limbic system
2. amygdala
3. The limbic system helps process some of the emotions related to this romantic interest (amygdala), sensations of seeing, hearin, and touching (thalamus), memories of past first dates (hippocampus and amygdala); it also ensures that some of our basic needs are met during the course of the date (hypothalamus). The brainstem controls life-sustaining activities, allowing us to divert our attention from breathing onto engaging in conversation. The cerebellum is responsible for balance and producing appropriate emotional reactions while on the date.
4. a. relay sensory information.

1. c. Neurons
2. a. an action potential
3. a. myelin sheath
4. 1. acetylcholine: c. enables movement; 2. glutamate: b. learning, memory; 3. endorphins: a. reduces experience of pain; 4. serotonin: d. mood, aggression, appetite
5. a. central nervous system.
6. b. spinal cord
7. d. peripheral nervous system
8. d. “rest-and-digest” process.
9. b. endocrine system; glands
10. b. The right hemisphere is more competent handling visual tasks.
11. a. locations in the brain are responsible for certain activities.
12. d. Wernicke’s area
13. 1. association area: b. integrates information from all over the brain; 2. temporal lobes: c. hearing and language comprehension; 3. meninges: a. three thin membranes protect brain; 4. occipital lobes: e. processes visual information; 5. parietal lobes: d. receives sensory information, such as touch
14. 1. amygdala: b. processes basic information; 2. hippocampus: a. responsible for making new memories; 3. hypothalamus: d. keeps body systems in steady state; 4. thalamus: c. relays sensory information
15. d. reticular formation
16. Answers will vary. Agonists boost normal neurotransmitter activity and antagonists dampen normal neurotransmitter activity. An agonist is somewhat like a substance you add to your car engine to increase its efficiency. An antagonist might be compared to a character in a novel who prevents a heroine from doing her job.
17. Diagrams will vary; see Figure 2.3. A reflex is an uncontrollable reaction that often protects us from bodily harm. For example, we automatically pull away when we touch a hot surface. Sensory neurons are activated and carry information from the environment to interneurons in the spinal cord, which activates motor neurons. The motor neurons excite the muscle and initiate the motion of pulling away.
18. Neurotransmitters are chemical messengers produced by neurons that enable communication between neurons. Hormones are chemical messengers produced by the endocrine system and released into the bloodstream. The effects of the neurotransmitters are almost instantaneous, whereas those of hormones are usually delayed and longer lasting. Both influence thoughts, emotions, and behaviors. Neurotransmitters and hormones can work together, for example directing the fight-or-flight response to stress.
19. Sperry and Gazzaniga’s research demonstrated that the hemispheres of the human brain, while strikingly similar in appearance, specialize in different functions. The left hemisphere excels in language processing, and the right hemisphere excels at visuospatial tasks. The corpus callosum normally allows the two hemispheres to share and integrate information.
20. The EEG detects electrical impulses in the brain. The CT uses X-rays to create many cross-sectional images of the brain. The MRI uses pulses of radio waves to produce more detailed cross-sectional images than those of a CT scan, but both MRI and CT are used to study the structure of the brain. The PET uses radioactivity to track glucose consumption and construct a map of brain activity. The fMRI also captures changes in brain activity, but instead of tracking glucose consumption, it reveals patterns of blood flow in the brain, which is a good indicator of how much oxygen is being used. All of these tools have strengths and limitations (see TABLE 2.1).

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ANSWER: Yes, Brandon would display a reflex. Remember that the knee jerk is an involuntary reaction carried out by neurons outside of the brain.