Ch.19 Autonomic Nervous System Test Bank Martin

Chapter 19: Autonomic Nervous System

Test Bank

Type: multiple choice question

Title: Chapter 19 Question 01

1. Activity of the autonomic nervous system is

Feedback: Learning Objective: Not aligned

Subhead: Introduction

Bloom’s Level: 2. Understanding

a. absent when we are sleeping or unconscious.

b. entirely independent of voluntary action.

c. under direct voluntary control.

d. not directly under voluntary control but may be controlled indirectly by voluntary action.

e. entirely independent of environmental conditions.

Type: multiple choice question

Title: Chapter 19 Question 02

2. The primary destination of autonomic neurons is

Feedback: Learning Objective: Describe the principal anatomical features and actions of the sympathetic and parasympathetic nervous systems.

Subhead: Functions under Involuntary Control

Bloom’s Level: 1. Remembering

a. skeletal muscle fibers.

b. other neurons in the brain.

c. the body’s organs and tissues.

d. the body’s sensory receptors.

e. the motor cortex.

Type: multiple choice question

Title: Chapter 19 Question 03

3. The system associated with the ‘fright, fight, and flight’ response is the _______ system.

Feedback: Learning Objective: Describe the principal anatomical features and actions of the sympathetic and parasympathetic nervous systems.

Subhead: Functions under Involuntary Control

Bloom’s Level: 1. Remembering

a. sympathetic

b. parasympathetic

c. cholinergic

d. limbic

e. autonomic ganglionic

Type: multiple choice question

Title: Chapter 19 Question 04

4. Ephedrine is a drug that affects the nervous system similarly to epinephrine. Knowing this, you would expect a person taking ephedrine to experience

Feedback: Learning Objective: Describe the principal anatomical features and actions of the sympathetic and parasympathetic nervous systems.

Subhead: Functions under Involuntary Control

Bloom’s Level: 3. Applying

a. symptoms such as reduced blood pressure, increased gut motility, and pupillary constriction.

b. symptoms such as increased blood pressure, reduced gut motility, and pupillary dilation.

c. a disruption of circadian rhythms.

d. increased appetite and/or overeating.

e. loss of muscular coordination.

Type: multiple choice question

Title: Chapter 19 Question 05

5. Compared to the sympathetic nervous system, the parasympathetic system

Feedback: Learning Objective: Describe the principal anatomical features and actions of the sympathetic and parasympathetic nervous systems.

Subhead: Functions under Involuntary Control

Bloom’s Level: 2. Understanding

a. has a more general, widespread effect on the body.

b. has more focused, selective effects.

c. is more directly under voluntary control.

d. is less directly under voluntary control.

e. tends to be associated with emotions.

Type: multiple choice question

Title: Chapter 19 Question 06

6. The structure of autonomic ganglia can be characterized as

Feedback: Learning Objective: Explain how, and why, the preganglionic and postganglionic axons of the parasympathetic nervous system differ from those of the sympathetic nervous system.

Subhead: Functions under Involuntary Control

Bloom’s Level: 1. Remembering

a. mainly convergent, with many preganglionic fibers innervating each ganglionic neuron.

b. mainly divergent, with each preganglionic fiber innervating many ganglionic neurons.

c. both convergent and divergent.

d. direct, with each preganglionic fiber innervating a single ganglionic neuron.

e. unknown, since the fibers are too entangled to map their connections.

Type: multiple choice question

Title: Chapter 19 Question 07

7. The axons of preganglionic neurons in the sympathetic system tend to be _______, while those in the parasympathetic system tend to be _______.

Feedback: Learning Objective: Explain how, and why, the preganglionic and postganglionic axons of the parasympathetic nervous system differ from those of the sympathetic nervous system.

Subhead: Functions under Involuntary Control

Bloom’s Level: 1. Remembering

a. myelinated; unmyelinated

b. unmyelinated; myelinated

c. long; short

d. short; long

e. unipolar; multipolar

Type: multiple choice question

Title: Chapter 19 Question 08

8. Ganglia of the parasympathetic nervous system are usually located

Feedback: Learning Objective: Explain how, and why, the preganglionic and postganglionic axons of the parasympathetic nervous system differ from those of the sympathetic nervous system.

Subhead: Functions under Involuntary Control

Bloom’s Level: 1. Remembering

a. close to the tissues or organs that they innervate.

b. inside the spinal cord.

c. close to the muscles that they control.

d. in the brainstem.

e. next to the spinal cord.

Type: multiple choice question

Title: Chapter 19 Question 09

9. Myelination of neurons in the autonomic nervous system is generally

Feedback: Learning Objective: Explain how, and why, the preganglionic and postganglionic axons of the parasympathetic nervous system differ from those of the sympathetic nervous system.

Subhead: Functions under Involuntary Control

Bloom’s Level: 1. Remembering

a. present in the sympathetic nervous system, with parasympathetic neurons being unmyelinated.

b. absent, with most neurons being unmyelinated.

c. present on preganglionic neurons, with postganglionic neurons being unmyelinated.

d. present on postganglionic neurons, with preganglionic neurons being unmyelinated.

e. present on both preganglionic and postganglionic neurons

Type: multiple choice question

Title: Chapter 19 Question 10

10. Direct, rapid transmission at autonomic ganglia differs from that in the neuromuscular junction in that

Feedback: Learning Objective: Describe the mechanism of direct, rapid transmission at autonomic ganglia.

Subhead: Functions under Involuntary Control

Bloom’s Level: 2. Understanding

a. the autonomic ganglia use nicotinic receptors while the neuromuscular junction uses muscarinic receptors.

b. the autonomic ganglion cells are activated by acetylcholine, while the neuromuscular junction uses glutamate.

c. unlike the neuromuscular junction, the autonomic ganglion cells are inhibited by presynaptic activity.

d. the autonomic ganglion cells are activated by epinephrine instead of acetylcholine.

e. the structure of nicotinic receptors in autonomic ganglion cells differs from those at the neuromuscular junction.

Type: multiple choice question

Title: Chapter 19 Question 11

11. The connection between autonomic ganglion neurons and their presynaptic neurons is such that

Feedback: Learning Objective: Describe the mechanism of direct, rapid transmission at autonomic ganglia.

Subhead: Functions under Involuntary Control

Bloom’s Level: 2. Understanding

a. an action potential in any presynaptic neuron is capable of producing an action potential in the ganglion cell.

b. some “strong” presynaptic neurons can produce action potentials in the ganglion cell, while other “weak” neurons produce subthreshold potentials.

c. all presynaptic neurons produce subthreshold potentials that must summate to produce an action potential.

d. an action potential in any presynaptic neuron is capable of inhibiting any action potentials in the ganglion cell.

e. only g-protein coupled receptors are present on the ganglion cell, so presynaptic firing does not produce any direct changes in postsynaptic potential.

Type: multiple choice question

Title: Chapter 19 Question 12

12. Muscarinic ACh receptors

Feedback: Learning Objective: Describe the mechanism of direct, rapid transmission at autonomic ganglia.

Subhead: Functions under Involuntary Control

Bloom’s Level: 2. Understanding

a. are not present in autonomic ganglion cells.

b. produce fast, direct activation of autonomic ganglion cells.

c. produce slow, long lasting activation of autonomic ganglion cells.

d. produce inhibition of autonomic ganglion cells.

e. are present in autonomic ganglion cells, but their function has not yet been determined.

Type: multiple choice question

Title: Chapter 19 Question 13

13. Nicotinic ACh receptors

Feedback: Learning Objective: Describe the mechanism of direct, rapid transmission at autonomic ganglia.

Subhead: Functions under Involuntary Control

Bloom’s Level: 2. Understanding

a. are not present in autonomic ganglion cells.

b. produce fast, direct activation of autonomic ganglion cells.

c. produce slow, long lasting activation of autonomic ganglion cells.

d. produce inhibition of autonomic ganglion cells.

e. are present in autonomic ganglion cells, but their function has not yet been determined.

Type: multiple choice question

Title: Chapter 19 Question 14

14. In frogs, excitatory signaling in autonomic ganglion cells appears to be controlled by

Feedback: Learning Objective: Describe the mechanism of direct, rapid transmission at autonomic ganglia.

Subhead: Functions under Involuntary Control

Bloom’s Level: 1. Remembering

a. neuropeptide Y and glutamate.

b. norepinephrine and gonadotropin-releasing hormone.

c. acetylcholine and nicotine.

d. glutamate and epinephrine.

e. acetylcholine and luteinizing hormone releasing hormone.

Type: multiple choice question

Title: Chapter 19 Question 15

15. Direct, rapid transmission at autonomic ganglia is produced when _______ is released, binding to _______ receptors.

Feedback: Learning Objective: Describe the mechanism of direct, rapid transmission at autonomic ganglia.

Subhead: Functions under Involuntary Control

Bloom’s Level: 2. Understanding

a. epinephrine; nicotinic

b. norepinephrine, adrenergic

c. purines; P

d. acetylcholine, nicotinic

e. acetylcholine; muscarinic

Type: multiple choice question

Title: Chapter 19 Question 16

16. M-currents are involved in a(n)

Feedback: Learning Objective: Discuss the physiological role of M-currents in the autonomic nervous system.

Subhead: Functions under Involuntary Control

Bloom’s Level: 2. Understanding

a. fast, direct excitatory potential in post-ganglionic autonomic neurons.

b. slow, long-lasting depolarization in post-ganglionic autonomic neurons.

c. fast, direct inhibitory potential in post-ganglionic autonomic neurons.

d. slow, long-lasting hyperpolarization in post-ganglionic autonomic neurons.

e. initiation of long-term potentiation in post-ganglionic autonomic neurons.

Type: multiple choice question

Title: Chapter 19 Question 17

17. M-channels (or KCNQ or K_v7 channels) are permeable primarily to

Feedback: Learning Objective: Discuss the physiological role of M-currents in the autonomic nervous system.

Subhead: Functions under Involuntary Control

Bloom’s Level: 1. Remembering

a. magnesium.

b. sodium.

c. chloride.

d. calcium.

e. potassium.

Type: multiple choice question

Title: Chapter 19 Question 18

18. Activation of muscarinic ACh receptors causes M-channels to

Feedback: Learning Objective: Discuss the physiological role of M-currents in the autonomic nervous system.

Subhead: Functions under Involuntary Control

Bloom’s Level: 2. Understanding

a. open, allowing an influx of potassium.

b. open, allowing an influx of sodium.

c. open, allowing an efflux of potassium.

d. close, reducing the efflux of potassium.

e. close, reducing the influx of sodium.

Type: multiple choice question

Title: Chapter 19 Question 19

19. The closing of an M-channel has the effect of

Feedback: Learning Objective: Discuss the physiological role of M-currents in the autonomic nervous system.

Subhead: Functions under Involuntary Control

Bloom’s Level: 2. Understanding

a. depolarizing the cell.

b. hyperpolarizing the cell.

c. maintaining the cell’s resting potential.

d. ending the activity of cyclic AMP.

e. None of the above

Type: multiple choice question

Title: Chapter 19 Question 20

20. The opening of an M-channel has the effect of

Feedback: Learning Objective: Discuss the physiological role of M-currents in the autonomic nervous system.

Subhead: Functions under Involuntary Control

Bloom’s Level: 2. Understanding

a. increasing the probability of an action potential.

b. decreasing the probability of an action potential.

c. lowering the resting potential of the cell.

d. increasing the magnitude of action potentials.

e. activation of cyclic AMP.

Type: multiple choice question

Title: Chapter 19 Question 21

21. Autonomic ganglion neurons switch from phasic-firing to tonic-firing when

Feedback: Learning Objective: Discuss the physiological role of M-currents in the autonomic nervous system.

Subhead: Functions under Involuntary Control

Bloom’s Level: 2. Understanding

a. M-channels are closed.

b. M-channels are opened.

c. Nicotinic ACh receptors are opened.

d. Nicotinic ACh receptors are closed.

e. C-cells are activated.

Type: multiple choice question

Title: Chapter 19 Question 22

22. The application of ACh to muscarinic receptors in autonomic ganglia would be expected to have this effect on the post-synaptic neuron.

Feedback: Learning Objective: Discuss the physiological role of M-currents in the autonomic nervous system.

Subhead: Functions under Involuntary Control

Bloom’s Level: 3. Application

a. Shift from tonic firing to phasic firing

b. Shift from phasic firing to tonic firing

c. Suppress all firing activity

d. No effect on firing activity

e. Induction of long-term potentiation

Type: multiple choice question

Title: Chapter 19 Question 23

23. In a neuron’s resting state, M-channels are likely to be

Feedback: Learning Objective: Discuss the physiological role of M-currents in the autonomic nervous system.

Subhead: Functions under Involuntary Control

Bloom’s Level: 1. Remembering

a. closed, reducing potassium conductance.

b. closed, reducing chloride conductance.

c. closed, reducing sodium conductance.

d. open, contributing to resting sodium conductance.

e. open, contributing to resting potassium conductance.

Type: multiple choice question

Title: Chapter 19 Question 24

24. The purine transmitters include

Feedback: Learning Objective: Name the principal transmitters released by sympathetic and parasympathetic axons.

Subhead: Transmitter Release by Postganglionic Axons

Bloom’s Level: 1. Remembering

a. acetylcholine and adenosine.

b. VIP and LHRH.

c. epinephrine and norepinephrine.

d. adenosine and ATP.

e. ATP and adrenaline.

Type: multiple choice question

Title: Chapter 19 Question 25

25. ATP is a major neurotransmitter in the

Feedback: Learning Objective: Name the principal transmitters released by sympathetic and parasympathetic axons.

Subhead: Transmitter Release by Postganglionic Axons

Bloom’s Level: 1. Remembering

a. sympathetic nervous system.

b. parasympathetic nervous system.

c. neuromuscular junction.

d. M-channel synapses.

e. adrenal medulla.

Type: multiple choice question

Title: Chapter 19 Question 26

26. P1 and P2 receptors are so named because they are

Feedback: Learning Objective: Name the principal transmitters released by sympathetic and parasympathetic axons.

Subhead: Transmitter Release by Postganglionic Axons

Bloom’s Level: 1. Remembering

a. prevalent in the parasympathetic nervous system.

b. activated by purines.

c. activated by polypeptides.

d. responsive to pain.

e. located in the pituitary.

Type: multiple choice question

Title: Chapter 19 Question 27

27. Beta-blockers, which block the actions of norepinephrine on b-receptors, can be used medically to treat

Feedback: Learning Objective: Explain how an understanding of the transmitters and receptors used by the autonomic nervous system has led to the development of new drugs for treating diseases

Subhead: Transmitter Release by Postganglionic Axons

Bloom’s Level: 1. Remembering

a. the inability to sleep.

b. high blood pressure.

c. overeating.

d. depression.

e. lethargy.

Type: multiple choice question

Title: Chapter 19 Question 28

28. Regulation of blood pressure based on body position is accomplished using

Feedback: Learning Objective: Give an example of a bodily response that illustrates the essential role played by sensory inputs and reflex regulation in the autonomic nervous system

Subhead: Transmitter Release by Postganglionic Axons

Bloom’s Level: 1. Remembering

a. stretch receptors in the carotid artery.

b. oxygen receptors in the brain.

c. activated by polypeptides.

d. responsive to pain.

e. only found in the peripheral nervous system.

Type: multiple choice question

Title: Chapter 19 Question 29

29. Excessive feeding _______; while starvation _______.

Feedback: Learning Objective: Give an example of a bodily response that illustrates the essential role played by sensory inputs and reflex regulation in the autonomic nervous system

Subhead: Transmitter Release by Postganglionic Axons

Bloom’s Level: 1. Remembering

a. activates the hypothalamus; inhibits the hypothalamus

b. stimulates GnRH; stimulates LHRH

c. inhibits melatonin; stimulates melatonin

d. increases leptin; decreases leptin

e. releases GABA; releases norepinephrine

Type: multiple choice question

Title: Chapter 19 Question 30

30. The enteric nervous system

Feedback: Learning Objective: Discuss why scientists still lack a complete understanding of how the enteric nervous system works.

Subhead: Transmitter Release by Postganglionic Axons

Bloom’s Level: 1. Remembering

a. is a useful model system because it is very simple with only a few neurons.

b. consists almost entirely of sensory neurons.

c. consists almost entirely of motor neurons.

d. contains all known neurotransmitters.

e. is fully understood in the lobster but not yet in humans.

Type: multiple choice question

Title: Chapter 19 Question 31

31. The enteric nervous system is still not well understood because

Feedback: Learning Objective: Discuss why scientists still lack a complete understanding of how the enteric nervous system works.

Subhead: Transmitter Release by Postganglionic Axons

Bloom’s Level: 1. Remembering

a. scientists have only recently begun to study its function.

b. the human enteric nervous system does not resemble that of any other species.

c. it contains an extremely large number of densely interconnected neural circuits.

d. electrical recordings cannot be used on these neurons.

e. it uses a different set of neurotransmitters than those found elsewhere.

Type: multiple choice question

Title: Chapter 19 Question 32

32. The region of the brain that is closely involved in regulation of the autonomic nervous system is the

Feedback: Learning Objective: Discuss how the hypothalamus and hormones regulate control of the autonomic nervous system.

Subhead: Transmitter Release by Postganglionic Axons

Bloom’s Level: 1. Remembering

a. hippocampus.

b. hypothalamus.

c. amygdala.

d. cerebellum.

e. limbic system.

Type: multiple choice question

Title: Chapter 19 Question 33

33. The hypothalamus controls functions such as

Feedback: Learning Objective: Discuss how the hypothalamus and hormones regulate control of the autonomic nervous system.

Subhead: Transmitter Release by Postganglionic Axons

Bloom’s Level: 1. Remembering

a. body temperature, appetite, heart rate, and growth.

b. coordination of complex skeletal motor activity.

c. emotions and empathy.

d. language comprehension and production.

e. fear and aggression.

Type: multiple choice question

Title: Chapter 19 Question 34

34. Leptin is

Feedback: Learning Objective: Discuss how the hypothalamus and hormones regulate control of the autonomic nervous system.

Subhead: Transmitter Release by Postganglionic Axons

Bloom’s Level: 1. Remembering

a. the principle neurotransmitter of the enteric nervous system.

b. a hormone released by the pituitary gland.

c. a protein involved in the regulation of blood pressure.

d. a peptide secreted by adipose cells.

e. a hormone released by hypothalamic neurons.

Type: multiple choice question

Title: Chapter 19 Question 35

35. If leptin is experimentally increased in the hypothalamus, the expected result would have which effect?

Feedback: Learning Objective: Discuss how the hypothalamus and hormones regulate control of the autonomic nervous system.

Subhead: Transmitter Release by Postganglionic Axons

Bloom’s Level: 3. Applying

a. An increase in food intake

b. A reduction in food intake

c. A reduction in energy expenditure

d. Loss of rhythmicity of circadian cycles

e. No effect since the hypothalamus is not responsive to leptin

Type: multiple choice question

Title: Chapter 19 Question 36

36. Communication from the hypothalamus to the pituitary occurs through

Feedback: Learning Objective: Discuss how the hypothalamus and hormones regulate control of the autonomic nervous system.

Subhead: Transmitter Release by Postganglionic Axons

Bloom’s Level: 2. Understanding

a. both hormone release and direct innervation by the hypothalamus.

b. release of melatonin by the hypothalamus.

c. purinergic transmission.

d. a sympathetic ganglion.

e. M-currents.

Type: multiple choice question

Title: Chapter 19 Question 37

37. One major mechanism by which the hypothalamus effects hormone secretion is releasing

Feedback: Learning Objective: Discuss how the hypothalamus and hormones regulate control of the autonomic nervous system.

Subhead: Transmitter Release by Postganglionic Axons

Bloom’s Level: 1. Remembering

a. Ach into the pituitary.

b. NE into the bloodstream.

c. melatonin into the SCN.

d. GnRH into the pituitary.

e. NE into the sympathetic ganglia.

Type: multiple choice question

Title: Chapter 19 Question 38

38. GnRH, or Gonadotropin-releasing hormone, is released by the

Feedback: Learning Objective: Discuss how the hypothalamus and hormones regulate control of the autonomic nervous system.

Subhead: Transmitter Release by Postganglionic Axons

Bloom’s Level: 1. Remembering

a. hypothalamus to act on the pituitary.

b. pituitary to act on the adrenal glands.

c. gonads to act on the hypothalamus.

d. hypothalamus to act on the gonads.

e. pituitary to act at locations all over the body.

Type: multiple choice question

Title: Chapter 19 Question 39

39. Circadian rhythms are regulated by the release of melatonin from the

Feedback: Learning Objective: Explain what circadian rhythms are and how they are influenced by melatonin

Subhead: Transmitter Release by Postganglionic Axons

Bloom’s Level: 1. Remembering

a. pineal gland.

b. pituitary gland.

c. hypothalamus.

d. limbic system.

e. optic nerve.

Type: multiple choice question

Title: Chapter 19 Question 40

40. The function of the hormone melatonin in humans is to

Feedback: Learning Objective: Explain what circadian rhythms are and how they are influenced by melatonin

Subhead: Transmitter Release by Postganglionic Axons

Bloom’s Level: 1. Understanding

a. induce sleep.

b. inhibit sleep.

c. regulate the sleep/wake cycle.

d. activate sympathetic activity.

e. coordinate reproductive behaviors.

Type: multiple choice question

Title: Chapter 19 Question 41

41. The structure in the brain that serves as an ‘internal clock’ for circadian rhythms is the

Feedback: Learning Objective: Explain how the suprachiasmatic nucleus (SCN) contributes to generating the biological clock that regulates circadian rhythms.

Subhead: Transmitter Release by Postganglionic Axons

Bloom’s Level: 1. Remembering

a. periaqueductal grey.

b. photo-optic ganglion.

c. hypothalamus.

d. pineal gland.

e. suprachiasmatic nucleus.

Type: multiple choice question

Title: Chapter 19 Question 42

42. The sensory input that entrains the day/night cycle come from the

Feedback: Learning Objective: Explain how the suprachiasmatic nucleus (SCN) contributes to generating the biological clock that regulates circadian rhythms.

Subhead: Transmitter Release by Postganglionic Axons

Bloom’s Level: 1. Remembering

a. specialized photoreceptive ganglion cells in the visual system.

b. rods in the retina.

c. pineal gland.

d. lateral geniculate nucleus.

e. paraventricular nucleus.

Type: multiple choice question

Title: Chapter 19 Question 43

43. Destruction of the Suprachiasmatic Nucleus (SCN) would be expected to result in

Feedback: Learning Objective: Explain how the suprachiasmatic nucleus (SCN) contributes to generating the biological clock that regulates circadian rhythms.

Subhead: Transmitter Release by Postganglionic Axons

Bloom’s Level: 3. Applying

a. hyperarousal and high activity levels.

b. loss of circadian rhythms.

c. Increased appetite and weight gain.

d. difficulty regulating heart rate and blood pressure.

e. reduction in sexual activity.

Type: multiple choice question

Title: Chapter 19 Question 44

44. The PER protein is involved in the function of

Feedback: Learning Objective: Explain how the suprachiasmatic nucleus (SCN) contributes to generating the biological clock that regulates circadian rhythms

Subhead: Transmitter Release by Postganglionic Axons

Bloom’s Level: 1. Remembering

a. maintaining circadian rhythms.

b. maintaining blood pressure.

c. regulating body weight.

d. opening M-channels.

e. hypothalamic regulation.

Type: multiple choice question

Title: Chapter 19 Question 45

45. If retinal rod and cone cells are inactivated

Feedback: Learning Objective: Explain how the suprachiasmatic nucleus (SCN) contributes to generating the biological clock that regulates circadian rhythms

Subhead: Transmitter Release by Postganglionic Axons

Bloom’s Level: 1. Remembering

a. circadian rhythms are abolished.

b. circadian rhythm cycles become longer.

c. circadian rhythm cycles become shorter.

d. animals behave as though they are constantly in the “night,” or dark, cycle.

e. circadian rhythms can still be entrained.

Type: multiple choice question

Title: Chapter 19 Question 46

46. The major transmitter in the rat SCN is

Feedback: Learning Objective: Explain how the suprachiasmatic nucleus (SCN) contributes to generating the biological clock that regulates circadian rhythms

Subhead: Transmitter Release by Postganglionic Axons

Bloom’s Level: 1. Remembering

a. norepinephrine.

b. acetylcholine.

c. GABA.

d. ATP.

e. glutamate.

Type: multiple choice question

Title: Chapter 19 Question 47

47. The role of GABA in the rat SCN is to

Feedback: Learning Objective: Explain how the suprachiasmatic nucleus (SCN) contributes to generating the biological clock that regulates circadian rhythms.

Subhead: Transmitter Release by Postganglionic Axons

Bloom’s Level: 2. Understanding

a. open chloride channels.

b. close chloride channels.

c. open sodium channels.

d. open potassium channels.

e. close potassium channels.

Type: multiple choice question

Title: Chapter 19 Question 48

48: In the drosophila ‘genetic clock, the PER/TIM protein complex

Feedback: Learning Objective: Explain how the suprachiasmatic nucleus (SCN) contributes to generating the biological clock that regulates circadian rhythms.

Subhead: Transmitter Release by Postganglionic Axons

Bloom’s Level: 2. Understanding

a. eliminates circadian rhythms.

b. leads to the release of melatonin.

c. binds to photoreceptors to help entrain circadian rhythms.

d. activates transcription of per and tim genes.

e. inhibits transcription of per and tim genes.

Type: multiple choice question

Title: Chapter 19 Question 49

49: If an experimenter were to bathe neurons of the Suprachiasmatic Nucleus (SCN) in GABA during the day, you would predict that he or she would observe

Feedback: Learning Objective: Explain how the suprachiasmatic nucleus (SCN) contributes to generating the biological clock that regulates circadian rhythms.

Subhead: Transmitter Release by Postganglionic Axons

Bloom’s Level: 3. Applying

a. an increase in action potentials in the SCN.

b. a reduction in action potentials in the SCN.

c. an increase in melatonin released by the SCN.

d. upregulation of PER and TIM proteins in the SCN.

e. no effect would be seen because the SCN is not responsive to GABA.

Type: essay/short answer question

Title: Chapter 19 Question 50

50. Ephedrine is a drug that is sometimes used to prevent low blood pressure. It is not safe for frequent use due to common side effects, including fast heart rate, anxiety, high blood pressure, and loss of appetite. Knowing these effects of ephedrine, develop a hypothesis about how this drug is likely to affect the autonomic nervous system.

Feedback: The effects of ephedrine appear to resemble activation of the sympathetic nervous system. Activation of the sympathetic nervous system leads to an increase in heart rate and in blood pressure and is associated with increased anxiety. Similarly, the reduction in gut motility is consistent with appetite loss. It would be logical to hypothesize that ephedrine stimulates the sympathetic nervous system, likely by mimicking the effects of epinephrine or norepinephrine.

Learning Objective: Describe the principal anatomical features and actions of the sympathetic and parasympathetic nervous systems

Subhead: Functions under Involuntary Control

Bloom’s Level: 4. Evaluating

Type: essay/short answer question

Title: Chapter 19 Question 51

51. Explain how fast, direct transmission occurs in autonomic ganglia. Include the main neurotransmitter, receptor types, and effects on receptors.

Feedback: An action potential in the preganglionic neuron releases acetylcholine, which binds to nicotinic receptors on the postsynaptic neuron. These open ion channels which lead to depolarization of the postsynaptic neuron, and an action potential.

Learning Objective: Describe the mechanism of direct, rapid transmission at autonomic ganglia.

Subhead: Functions under Involuntary Control

Bloom’s Level: 2. Understanding

Type: essay/short answer question

Title: Chapter 19 Question 52

52. What is the functional effect on a neuron when an M-channel is opened?

Feedback: The opening of an M-channel allows potassium to flow out of the neuron. This outward current counteracts the inward sodium current, reducing depolarization. This reduces the probability of firing an action potential.

Learning Objective: Discuss the physiological role of M-currents in the autonomic nervous system.

Subhead: Functions under Involuntary Control

Bloom’s Level: 2. Understanding

Type: essay/short answer question

Title: Chapter 19 Question 53

53. Muscarine is a deadly toxin found in some mushrooms, with symptoms including decreased heart rate, hypotension (low blood pressure), and diarrhea. Knowing that it acts as a muscarinic receptor agonist, make a prediction about the mechanism by which these effects occur.

Feedback: Muscarinic ACh receptors exist in autonomic ganglion neurons, where they lead to the closure of M-channels, and they are in neurons at the target locations of the parasympathetic system. When applied to the ganglion neurons, muscarine reduces potassium outflow, thus increasing the activity of these neurons. The observed symptoms are consistent with overactivation of the parasympathetic system, and can be explained by stimulating parasympathetic targets directly, and possibly by overactivity at the autonomic ganglia.

Subhead: Functions under Involuntary Control

Learning Objective: Discuss the physiological role of M-currents in the autonomic nervous system.

Bloom’s Level: 4. Analyzing

Type: essay/short answer question

Title: Chapter 19 Question 54

54. Give one example of a drug for treating a disease that was discovered through the study of the sympathetic nervous system.

Feedback: One example is asthma, in which bronchoconstriction can make it difficult to breathe. Epinephrine acts on b₂-receptors, which leads to bronchodilation. Doctors now use epinephrine or other b₂-agonists to induce bronchodilation and allow asthma patients to breathe more easily.

Learning Objective: Explain how an understanding of the transmitters and receptors used by the autonomic nervous system has led to the development of new drugs for treating diseases

Subhead: Transmitter Release by Postganglionic Axons

Bloom’s Level: 2. Understanding

Type: essay/short answer question

Title: Chapter 19 Question 55

55. Compare the activity of the carotid sinus neurons, and the resulting effect on cardiovascular sympathetic outputs, when the body is in the vertical position and when it is in the horizontal position.

Feedback: When the body is in the vertical position, pressure in the carotid artery is low, and carotid sinus neurons fire at a low rate. This reduces inhibition on sympathetic outputs, which results in constriction of blood vessels and increased heart rate. When the body is in the horizontal position, pressure in the carotid artery is high, and the firing rate of carotid sinus neurons increases. This results in inhibition of sympathetic outputs, and a reduction in blood pressure and heart rate.

Learning Objective: Give an example of a bodily response that illustrates the essential role played by sensory inputs and reflex regulation in the autonomic nervous system.

Subhead: Transmitter Release by Postganglionic Axons

Bloom’s Level: 2. Understanding

Type: essay/short answer question

Title: Chapter 19 Question 56

56. Give three reasons why the enteric nervous system has been so difficult to fully understand.

Feedback: First, there are over 10 million neurons in this system. Second, every known neurotransmitter is used in the enteric system. Third, there are a large number of local internal connections. (potentially fourth, the system is not static, but is rather extremely modifiable)

Learning Objective: Discuss why scientists still lack a complete understanding of how the enteric nervous system works.

Subhead: Transmitter Release by Postganglionic Axons

Bloom’s Level: 1. Remembering

Type: essay/short answer question

Title: Chapter 19 Question 57

57. Give two examples of pathways by which the hypothalamus can stimulate hormone release.

Feedback: Once example is circadian rhythms, when input from the SCN of the hypothalamus stimulates the pineal gland to secrete melatonin, helping to regulate sleep/wake cycles. A second example is in reproduction, when the hypothalamus releases GnRH, which stimulates the pituitary to release gonadotrophin, a hormone that helps regulate reproductive activity.

Learning Objective: Discuss how the hypothalamus and hormones regulate control of the autonomic nervous system.

Subhead: Transmitter Release by Postganglionic Axons

Bloom’s Level: 2. Understanding

Type: essay/short answer question

Title: Chapter 19 Question 58

58. Describe the pathway by which leptin regulates body weight.

Feedback: Leptin is released by adipose cells in the body. It binds to hypothalamic neurons, which activate the sympathetic nervous system, increasing energy expenditure and reducing food intake. This in turn reduces fat stores, causing a reduction in leptin release.

Learning Objective: Discuss how the hypothalamus and hormones regulate control of the autonomic nervous system.

Subhead: Transmitter Release by Postganglionic Axons

Bloom’s Level: 2. Understanding

Type: essay/short answer question

Title: Chapter 19 Question 59

59. How does the function of melatonin in humans compare with its function in other species?

Feedback: In humans, melatonin helps to regulate sleep/wake cycles. In many other species, it is also involved in circadian rhythms, but in seasonal rather than day/night cycles. Melatonin helps to suppress reproductive behavior in many species during the darker winter season. (In frogs, melatonin affects skin color.)

Learning Objective: Explain what circadian rhythms are and how they are influenced by melatonin

Subhead: Transmitter Release by Postganglionic Axons

Bloom’s Level: 1. Remembering

Type: essay/short answer question

Title: Chapter 19 Question 60

60. What is the chain of events leading to the release of melatonin?

Feedback: Melatonin is synthesized in, and released from, the pineal gland. It is released in greater quantities at night, receiving the signal about light cycle through the sympathetic nervous system from the SCN, which in turn receives light information from the retina.

Learning Objective: Explain what circadian rhythms are and how they are influenced by melatonin.

Subhead: Transmitter Release by Postganglionic Axons

Bloom’s Level: 2. Understanding

Type: essay/short answer question

Title: Chapter 19 Question 61

61. You have a friend who recently told you that they are too stressed with all of their schoolwork, and can’t fall asleep at night. They have started taking melatonin supplements in the evening in order to help them go to sleep. How would you respond to your friend?

Feedback: While melatonin is secreted in larger amounts at night, it does not appear to actually cause people to fall asleep. Instead, it is helpful to regulate or reset a sleep-wake cycle that has been disturbed. So, it might be useful to your friend if they are trying to get back onto a regular sleep schedule after pulling some all-night study sessions, but it’s unlikely to be helpful for falling asleep directly.

Learning Objective: Explain what circadian rhythms are and how they are influenced by melatonin.

Subhead: Transmitter Release by Postganglionic Axons

Bloom’s Level: 5. Evaluating

Type: essay/short answer question

Title: Chapter 19 Question 62

62. Explain how GABA can serve sometimes as an excitatory, and sometimes an inhibitory, neurotransmitter in the SCN.

Feedback: GABA opens chloride channels in some SCN neurons. The effects of opening these channels depends on the intracellular chloride concentrations. When intracellular concentrations are low, chloride equilibrium potential is more negative than resting, so GABA hyperpolarizes the neuron. When chloride concentrations are higher, the equilibrium potential is more positive than resting, so GABA depolarizes the neuron. Chloride transporters (NKCC1 and KCC2) regulate chloride concentrations across the day/night cycle, which leads to the different effects of GABA.

Learning Objective: Explain how the suprachiasmatic nucleus (SCN) contributes to generating the biological clock that regulates circadian rhythms.

Subhead: Transmitter Release by Postganglionic Axons

Bloom’s Level: 2. Understanding

Type: essay/short answer question

Title: Chapter 19 Question 63

63. Where are the sensory receptors that detect light/dark signals used to entrain circadian rhythms?

Feedback: There are special ganglion cells in the retina that also act as photoreceptors, which use melanopsin. These project directly to the SCN, and appear to be responsible for entraining the day/night cycle.

Learning Objective: Explain how the suprachiasmatic nucleus (SCN) contributes to generating the biological clock that regulates circadian rhythms.

Subhead: Transmitter Release by Postganglionic Axons

Bloom’s Level: 1. Remembering

Type: essay/short answer question

Title: Chapter 19 Question 64

64. Describe what you would expect to see if you were to apply bicuculline (a GABA antagonist) to a slice of rat SCN, and observe an extracellular recording for 24 hours.

Feedback: Normally, SCN neurons would show a high level of activity during the day, and lower levels at night. This effect is dependent on GABA, so bicuculline would be expected to eliminate or reduce the day/night differences.

Learning Objective: Explain how the suprachiasmatic nucleus (SCN) contributes to generating the biological clock that regulates circadian rhythms.

Subhead: Transmitter Release by Postganglionic Axons

Bloom’s Level: 3. Applying