REVIEW Neural and Hormonal Systems

Learning Objectives

47

Test Yourself by taking a moment to answer each of these Learning Objective Questions (repeated here from within the module). Research suggests that trying to answer these questions on your own will improve your long-term memory of the concepts (McDaniel et al., 2009).

Question

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ANSWER: Psychologists working from a biological perspective study the links between biology and behavior. We are biopsychosocial systems, in which biological, psychological, and social-cultural factors interact to influence behavior.

Question

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ANSWER: Neurons are the basic building blocks of the nervous system, the body's speedy electrochemical information system. A neuron receives signals through its branching dendrites, and sends signals through its axons. Some axons are encased in a myelin sheath, which enables faster transmission. Glial cells provide myelin, and they support, nourish, and protect neurons; they may also play a role in learning and thinking. If the combined signals received by a neuron exceed a minimum threshold (about negative 55 millivolts), the neuron fires, transmitting an electrical impulse (the action potential) down its axon by means of a chemistry-to-electricity process. The neuron's reaction is an all-or-none process. Absolute or relative refractory periods are tiny (millisecond) breaks between action potentials.

Question

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ANSWER: When action potentials reach the end of an axon (the axon terminals), they stimulate the release of neurotransmitters. These chemical messengers carry a message from the sending neuron across a synapse to receptor sites on a receiving neuron. The sending neuron, in a process called reuptake, then normally reabsorbs the excess neurotransmitter molecules in the synaptic gap. If incoming signals are strong enough, the receiving neuron generates its own action potential and relays the message to other cells.

Question

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ANSWER: Neurotransmitters travel designated pathways in the brain and may influence specific behaviors and emotions. Acetylcholine (ACh) affects muscle action, learning, and memory. Endorphins are natural opiates released in response to pain and exercise. Drugs and other chemicals affect brain chemistry at synapses. Agonists increase a neurotransmitter's action, and may do so in various ways. Antagonists decrease a neurotransmitter's action by blocking production or release.

Question

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ANSWER: The central nervous system (CNS)—the brain and the spinal cord—is the nervous system's decision maker. The peripheral nervous system (PNS), which connects the CNS to the rest of the body by means of nerves, gathers information and transmits CNS decisions to the rest of the body. The two main PNS divisions are the somatic nervous system (which enables voluntary control of the skeletal muscles) and the autonomic nervous system (which controls involuntary muscles and glands by means of its sympathetic and parasympathetic divisions). Neurons cluster into working networks. There are three types of neurons: (1) Sensory (afferent) neurons carry incoming information from sensory receptors to the brain and spinal cord. (2) Motor (efferent) neurons carry information from the brain and spinal cord out to the muscles and glands. (3) Interneurons communicate within the brain and spinal cord and between sensory and motor neurons.

Question

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ANSWER: The endocrine system is a set of glands that secrete hormones into the bloodstream, where they travel through the body and affect other tissues, including the brain. The endocrine system's master gland, the pituitary, influences hormone release by other glands, including the adrenal glands. In an intricate feedback system, the brain's hypothalamus influences the pituitary gland, which influences other glands, which release hormones, which in turn influence the brain.

Terms and Concepts to Remember

Test yourself on these terms.

Question

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

Experience the Testing Effect

Test yourself repeatedly throughout your studies. This will not only help you figure out what you know and don’t know; the testing itself will help you learn and remember the information more effectively thanks to the testing effect.

Question 2.1

1. The neuron fiber that passes messages through its branches to other neurons or to muscles and glands is the c01uBIDYpUx8tI7S .

Question 2.2

8RvsEOTh9sZ49+346wv2mjIer1MgUZuKmenrvZs1klLy/RXr+brb92NhDwKltXS0KyaH7Fd2a9VUJiEOhcvL75eieuWg9F1j73oML1e59XwImQ+KoKrScyhUYk4aJ6ooN+SxFK+ssXSnebIxcKRKwjnGSL4mxkHGjhOx33Yqfzr02A7ebo9oE6N+fbB1dpzZQGGs3TDTcHpF0CAEoO6Dt4RWITyCzXGjCU4Ijgp35eg+Q4l2P9GwnNR62uT8W/THCdRix+QVciksG9alELuA8ICaXYoRBcfgmgNgBQ==

Question 2.3

D3ySuZxacTGosm67I8NW0mfX6wT1I/ZDCjKYyRjY20zAZCA2di3EZdoTTYLjOEdHLytl1nUwQpJMPIF4yPS++8yXivvmd4l9uPXnZuQ10mBPKrcAhMbVI/qs4KKcXXoWiA4S/FvggMV3Ndl/DTWBM8XdIDSG1fjF7L6fcSaoakBT2bIOm1TA1gs9vGJ4LLESScBc9Zis8q8kg2zB4s49lPpTNITnMZKwv7EroizZlJdT0T/dPxksw9agLhRIgbvmnLmhzUcUNMpDSbFiH3Lc+j5FcK5P+D18sRdfqCZGKvktXlWbAjF3nwhAz+4izMmTtoZP3WSnoP9afbaYs0GR4g6V2Qtq49VykcDsjsjayQD1FNOmi/Fn3PBJHjkKKCjW

Question 2.4

4. In a sending neuron, when an action potential reaches an axon terminal, the impulse triggers the release of chemical messengers called u8rE4t5YvvXjjIy372QAMLV58g+JWyvq .

Question 2.5

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Question 2.6

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Question 2.7

7. The sympathetic nervous system arouses us for action and the parasympathetic nervous system calms us down. Together, the two systems make up the zPifQ5brCURiYGiU6ARqUA== nervous system.

Question 2.8

8. The neurons of the spinal cord are part of the vpPLI5kUu2Wk5ObV nervous system.

Question 2.9

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Question 2.10

10. The YW0Ngl97GCK752qb7np27sTogoJR5xkIEk90JfPbDIED7Z3e secrete(s) epinephrine and norepinephrine, helping to arouse the body during times of stress.

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