Florida International University

BIO PCB 4023

Chapter 11

1)The autonomic nervous system innervates all the following effector organs and tissues EXCEPT

1. 1. cardiac muscles.
   2. endocrine glands.
   3. exocrine glands.
   4. skeletal muscles.
   5. adipose tissues.

2. Dual innervation of organs by the autonomic nervous system refers to the observation that
   1. autonomic innervation involves preganglionic and postganglionic neurons.
   2. both sympathetic and parasympathetic neurons innervate most organs.
   3. autonomic and somatic neurons innervate all organs.
   4. two postganglionic sympathetic neurons innervate each target organ.
   5. autonomic neurons that innervate each target organ originate from two ganglia.
3. Which of the following physiological responses is associated with elevated sympathetic nervous system activity?
   1. increased contractile force of the heart
   2. enhanced absorption of nutrients
   3. enhanced digestion
   4. inhibition of cardiovascular function
   5. decreased heart rate
4. Which of the following physiological responses is associated with an elevation in parasympathetic nervous system activity?
   1. increased heart rate
   2. enhanced absorption of nutrients
   3. enhanced mobilization of energy stores
   4. shifting blood flow away from the gastrointestinal tract
   5. increased contractile force of the heart
5. At rest, what is the relative contribution of the sympathetic and parasympathetic nervous systems to the regulation of homeostasis?
   1. Only the parasympathetic system is active.
   2. Only the sympathetic system is active.
   3. Both systems are active but the parasympathetic predominates.
   4. Both systems are active but the sympathetic predominates.
   5. Neither system is active.

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6. When the body is stressed, what is the relative contribution of the sympathetic and parasympathetic nervous systems to the regulation of homeostasis?
   1. Only the parasympathetic system is active.
   2. Only the sympathetic system is active.
   3. Both systems are active but the parasympathetic predominates.
   4. Both systems are active but the sympathetic predominates.
   5. Neither system is active.
7. Which of the following best describes the general arrangement of the efferent limb of the autonomic nervous system?
   1. one neuron
   2. two neurons in parallel
   3. two neurons in series
   4. three neurons in series
   5. three neurons in parallel

8. Located entirely within the autonomic ganglia, cells that modulate the flow of information to the target organ are called         neurons.
   1. postganglionic
   2. intrinsic
   3. intraganglionic
   4. ganglionic
   5. preganglionic
9. Where do the preganglionic neurons of the sympathetic nervous system emerge from the spinal cord?
   1. lumbar and sacral regions
   2. lumbar region only
   3. thoracic and lumbar regions
   4. thoracic region only
   5. sacral region only
10. Sympathetic ganglia that are linked together and run in parallel on either side of the spinal column are called
    1. sympathetic chains or trunks.
    2. lateral horns.
    3. gray ramus.
    4. collateral ganglia.
    5. white ramus.

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11. Which of the following contributes to the ability of the sympathetic nervous system to produce widespread responses within the body?
    1. One postganglionic neuron branches into many collaterals that affect multiple organs.
    2. One preganglionic neuron can activate only one postganglionic neuron.
    3. Several preganglionic neurons activate a single postganglionic neuron.
    4. Multiple preganglionic neurons innervate each ganglion, sending out individual postganglionic neurons.
    5. One preganglionic neuron sends collaterals to multiple ganglia, affecting multiple postganglionic neurons.

12. Which of the following endocrine glands is innervated by sympathetic preganglionic neurons?
    1. adrenal medulla
    2. thyroid gland
    3. anterior pituitary
    4. pancreas
    5. adrenal cortex
13. Which of the following is indicative of the relative release of catecholamines from the adrenal medulla?
    1. 80% norepinephrine : 20% dopamine
    2. 80% norepinephrine : 20% epinephrine
    3. 100% acetylcholine
    4. 80% epinephrine : 20% dopamine
    5. 80% epinephrine : 20% norepinephrine
14. Which of the following descriptions of collateral ganglia is TRUE?
    1. Collateral ganglia are part of the somatic nervous system, located where the motor neuron leaves the ventral horn.
    2. Collateral ganglia are located within a chain just outside the spinal cord and are the sites of communication between sympathetic preganglionic neurons and postganglionic neurons.
    3. Collateral ganglia are in the sympathetic nervous system but distinct from the sympathetic chain, and they function as a site of communication between sympathetic preganglionic neurons and postganglionic neurons.

1. 4. Collateral ganglia are part of the somatosensory system, located off of the afferent neuron just prior to entering the spinal cord dorsal horn.
   5. Collateral ganglia are located within the effector organs and are the sites of communication between parasympathetic preganglionic neurons and postganglionic neurons.

15. Preganglionic and postganglionic sympathetic neurons are anatomically arranged in what three patterns?
    1. nicotinic ganglia, adrenergic ganglia, and cholinergic ganglia
    2. visceral, systemic, and cardiovascular
    3. sympathetic chains, those that innervate the adrenal medulla, and collateral ganglia
    4. sympathetic, parasympathetic, and involuntary nervous systems
    5. alpha, gamma, and beta cells

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16. Where in the central nervous system do the preganglionic neurons of the parasympathetic nervous system originate?
    1. brainstem and sacral region of the spinal cord
    2. thoracic region of the spinal cord only
    3. lumbar region of the spinal cord only
    4. sacral region of the spinal cord only
    5. thoracic and lumbar regions of the spinal cord
17. Parasympathetic preganglionic neurons travel in what nerves?
    1. pelvic nerves only
    2. cranial nerves only
    3. spinal nerves only
    4. cranial and spinal nerves
    5. cranial and pelvic nerves
18. Parasympathetic neurons from which cranial nerve innervate most of the viscera in the thoracic and abdominal cavities?
    1. I B) III C) VII D) IX E) X
19. Parasympathetic preganglionic neurons release the neurotransmitter ; sympathetic preganglionic neurons release the neurotransmitter .
    1. acetylcholine : norepinephrine
    2. acetylcholine : acetylcholine
    3. norepinephrine : acetylcholine
    4. norepinephrine : norepinephrine
    5. epinephrine : norepinephrine
20. Parasympathetic postganglionic neurons release the neurotransmitter           ; sympathetic postganglionic neurons release the neurotransmitter                          .
    1. acetylcholine : acetylcholine
    2. acetylcholine : norepinephrine
    3. epinephrine : norepinephrine
    4. norepinephrine : acetylcholine
    5. norepinephrine : norepinephrine
21. Binding of acetylcholine to        receptors causes          by opening channels that primarily permit sodium to permeate the membrane.
    1. muscarinic : a hyperpolarization
    2. nicotinic : a hyperpolarization
    3. nicotinic : no change in membrane potential
    4. muscarinic : a depolarization
    5. nicotinic : a depolarization

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22. Binding of norepinephrine or epinephrine to a(n) receptor will activate an inhibitory G protein which decreases the activity of adenylate cyclase and therefore cAMP synthesis while the binding of these two neurotransmitters to a      receptor will do the exact opposite.

A) !1 : !2 B) "2 : "1 C) !2 : "1 D) "1 : "2 E) !2 : !1

23. Compared to norepinephrine, epinephrine has a greater affinity for what type of receptor?
    1. "1 B) nicotinic C) !1 D) muscarinic E) "2
24. "2 adrenergic receptor agonists are used to treat acute asthma symptoms by eliciting a response similar to

             , which has a greater affinity for "2 receptors and leads to dilation of the respiratory pathways.

24. 1. atropine
    2. epinephrine
    3. norepinephrine
    4. acetylcholine
    5. cyclic AMP
25. Propranolol is a non-selective " adrenergic receptor antagonist. It would be appropriate for a doctor to prescribe propranolol to treat
    1. hypertension.
    2. myasthenia gravis.
    3. peptic ulcers.
    4. low blood pressure.
    5. asthma.
26. Actions at which class of adrenergic receptor generally have inhibitory effects?
    1. "1 B) !1 and "1 C) !1 D) "2 E) nicotinic
27. What are swellings of postganglionic autonomic axons from which neurotransmitters are released called?
    1. sympathetic trunks
    2. varicosities
    3. neuromuscular junctions
    4. ganglia
    5. parasympathetic chains
28. The presence of          within varicosities initiates the release of neurotransmitter.
    1. voltage-gated Ca2+ channels
    2. voltage-gated K+ channels
    3. mechanically-gated Na+ channels
    4. mechanically-gated Ca2+ channels
    5. voltage-gated Na+ channels

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29. What enzyme degrades the neurotransmitter released from varicosities of parasympathetic postganglionic neurons?
    1. choline acetyl transferase
    2. monoamine oxidase only
    3. catechol-O-methyltransferase only
    4. catechol-O-methyltransferase and monoamine oxidase
    5. acetylcholinesterase
30. In what class of autonomic neuron and within what organelle is the enzyme monoamine oxidase located?
    1. mitochondria of sympathetic postganglionic neurons
    2. Golgi apparatus of parasympathetic postganglionic neurons
    3. synaptic vesicles of sympathetic postganglionic neurons
    4. lysosomes of sympathetic preganglionic neurons

30. 5. smooth ER of parasympathetic postganglionic neurons
31. One of the adaptations that occur to muscles due to exercise is that contractions become stronger and steadier over time even with no change in muscle mass. Which statement below best explains why muscle contractions may become stronger?
    1. Muscle fibers reflexively start generating force even before the motor neurons send action potentials.
    2. The action potentials sent by the motor neurons get larger and last longer to produce more force in the muscles.
    3. The skeletal muscle contraction is enhanced by an increased input from the sympathetic nervous system.
    4. Motor neurons are activated more rapidly to generate a stronger muscle contraction.
    5. More motor neurons are made so that more action potentials can be sent down to the muscles.
32. People who have done a lot of endurance training can have a resting heart rate of 50 beats per minute compared to the normal resting heart rate of 70-80 beats per minute. This decreased heart rate in trained individuals is the partly result of
    1. endorphins released from the brain which have an inhibitory effect on heart rate.
    2. parasympathetic activity becoming more active and sympathetic activity becoming less active at rest.
    3. decreases in both sympathetic and parasympathetic activity.
    4. sympathetic activity becoming more active and parasympathetic activity becoming less active at rest.
    5. increases in both sympathetic and parasympathetic activity.
33. What area of the brain initiates the fight-or-flight response by producing widespread activation of the sympathetic nervous system?
    1. hypothalamus
    2. limbic system
    3. cerebellum
    4. amygdala
    5. brainstem

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34. Where are most of the autonomic nervous system control centers located?
    1. limbic system
    2. frontal lobe
    3. thalamus
    4. brainstem
    5. spinal cord
35. Scopolamine is a muscarinic antagonist that acts by blocking muscarinic acetylcholine receptors. Although it is not clear how scopolamine prevents nausea and vomiting due to motion sickness, which statement below

best describes the mechanism of action for this drug?

1. 1. Scopolamine causes chloride channels to open causing a subthreshold graded potential in the soma of the cell and, therefore, no action potential is ever generated that may cause motion sickness.
   2. Scopolamine works by preventing calcium influx at the axon terminal, therefore preventing the release of neurotransmitter.
   3. Scopolamine prevents communication between the nerves of the vestibule and the vomiting center in the brain by blocking the action of acetylcholine.
   4. Scopolamine breaks down acetylcholine in the synaptic cleft, therefore blocking the drug from entering the neuron.
   5. Scopolamine works on the optic nerve blocking sodium channels so that the sight of motion does not make an individual sick.

36. Students who suffer from test anxiety often have some of the following symptoms: the need for frequent urination, dilated pupils, and a dry mouth. What branch of the autonomic nervous system would cause

these symptoms?

1. 1. parasympathetic

36. 2. voluntary
    3. sympathetic
    4. somatic
    5. enteric
37. The somatic nervous system regulates the activity of
    1. many organs.
    2. endocrine organs.
    3. skeletal muscle.
    4. the kidneys.
    5. the cardiovascular system.
38. The somatic nervous system is often referred to as the system.
    1. unconscious
    2. craniosacral
    3. voluntary
    4. involuntary
    5. neuromuscular

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39. With respect to their innervation, individual skeletal muscle fibers (cells) are innervated by
    1. a single motor neuron.
    2. multiple motor neurons.
    3. a single motor neuron and autonomic neuron.
    4. multiple motor neurons and autonomic neurons.
    5. a single motor neuron and multiple autonomic neurons.
40. What is the neurotransmitter released from motor neurons?
    1. epinephrine
    2. norepinephrine
    3. GABA
    4. acetylcholine
    5. dopamine
41. Where on skeletal muscle is the highest density of nicotinic receptors?
    1. motor end plate
    2. axon hillock
    3. dendrites
    4. motor unit
    5. terminal bouton
42. Which of the following is located between the invaginations of the motor end plate of a neuromuscular junction?
    1. muscarinic receptors
    2. acetylcholinesterase
    3. "2 receptors
    4. nicotinic receptors
    5. "3 receptors
43. What is the graded change in membrane potential that occurs at the motor end plate of skeletal muscle called?
    1. end-plate potential
    2. action potential
    3. inhibitory postsynaptic potential
    4. adrenergic potential
    5. muscarinic potential

44. The opening of a cation channel that allows both Na+ and K+ to move through will cause the membrane to

              because of the          .

1. 1. depolarize : greater Na+ electrochemical gradient as compared with K+
   2. not change : same electrochemical gradient for K+ and Na+
   3. depolarize : greater K+ electrochemical gradient as compared with Na+
   4. hyperpolarize : greater Na+ electrochemical gradient as compared with K+
   5. hyperpolarize : greater K+ electrochemical gradient as compared with Na+

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45. Which of the following statements is TRUE of communication across the neuromuscular junction?
    1. Acetylcholinesterase located in the cytosol of the motor neuron degrades acetylcholine to acetate and choline.
    2. Acetylcholine released from a motor neuron binds to muscarinic cholinergic receptors.
    3. The end-plate potential is always of sufficient magnitude to depolarize the muscle cell to threshold to initiate an action potential.
    4. Synaptic communication to the muscle cell can be excitatory or inhibitory.
    5. Acetylcholinesterase located in mitochondria of the motor neuron degrades acetylcholine to acetate and choline.

46. How does latroxin, the venom of the black widow spider, cause muscle spasms and rigidity?
    1. It blocks nicotinic cholinergic receptors.
    2. It inhibits the degradation of acetylcholine at all synapses.
    3. It stimulates acetylcholine release from autonomic preganglionic neurons.
    4. It inhibits acetylcholine release from motor neurons.
    5. It stimulates acetylcholine release from motor neurons.
47. What is the correct order for the steps of synaptic transmission at the motor end plate?

1. Acetylcholine binds to postsynaptic receptors.
2. Acetylcholine is released by exocytosis.
3. A graded depolarization is produced.
4. An action potential is produced on the muscle cell membrane.
5. Channels that primarily allow diffusion of sodium are opened.
6. Voltage-dependent calcium channels on the plasma membrane open.
7. An action potential arrives at the axon terminal. A) 6, 7, 2, 1, 3, 5, 4

B) 7, 5, 2, 1, 3, 4, 6

C) 7, 6, 2, 1, 5, 3, 4

D) 5, 7, 6, 2, 1, 4, 3

E) 7, 6, 2, 1, 3, 4, 6

48. Myasthenia gravis primarily affects women and its defining characteristic is fatigue of unusually rapid onset and severity following the use of certain muscle groups. What symptoms below best allude to the set of

muscles affected by this disease?

1. 1. difficulty walking due to fatigue in the major muscles of the legs
   2. difficulty in fine motor control of the fingers, especially the thumb
   3. relaxed bladder causing frequent urination
   4. difficulty moving the joints of the fingers and toes
   5. difficulty speaking, difficulty swallowing, and drooping eyelids

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49. Which statement best describes the results of the autoimmune disease myasthenia gravis?
    1. There is blocking of sodium channels in the axon of the presynaptic axon.
    2. A decrease in the number of functional receptors on the muscle cell surface impairs its ability to respond to acetylcholine.
    3. There is a decrease in the amount of acetylcholine released from the synaptic terminal.

1. 4. There is degradation of the enzyme acetylcholinesterase.
   5. Communication at the neuromuscular junction is blocked by preventing acetylcholine from binding to nicotinic cholinergic receptors.

50. What is the primary mode of action of curare?
    1. It decreases the amount of acetylcholine released from the synaptic terminal.
    2. It blocks communication at the neuromuscular junction by preventing acetylcholine from binding to nicotinic cholinergic receptors.
    3. It blocks the sodium channels in the axon of the presynaptic axon.
    4. It decreases the number of functional receptors on the muscle cell by the process of phagocytosis, which impairs the ability of neurons to respond to acetylcholine.
    5. It causes the degradation of the enzyme acetylcholinesterase.
51. Sympathetic preganglionic neurons exit the spinal cord via the                        root, and then join the spinal nerve. They leave the spinal nerve and enter the ganglion via the   ramus. Most of the postganglionic fibers return to the spinal nerve via the    ramus.
    1. ventral : white : gray
    2. ventral : gray : white
    3. dorsal : gray: gray
    4. dorsal : gray : white
    5. dorsal : white : gray
52. The cranial nerve that innervates most of the viscera in the thoracic and abdominal cavities is the
    1. IX, or glossopharyngeal nerve.
    2. VII, or facial nerve.
    3. X, or vagus nerve.
    4. III, or oculomotor nerve.
    5. VIII, or vestibulocochlear nerve.
53. Adrenergic receptors with the greatest affinity for epinephrine are     receptors.
    1. alpha 1 B) beta 3 C) beta 2 D) beta 1 E) alpha 2
54. Binding of acetylcholine to        receptors will activate a G protein.
    1. somatostatic
    2. adrenergic
    3. muscarinic
    4. cholinergic
    5. nicotinic  10
55. Postganglionic neurons of the autonomic nervous system release neurotransmitter from
    1. dendrites.
    2. neuromuscular junction.
    3. varicosities.
    4. somas.
    5. axon hillock.
56. The change in membrane potential that occurs in skeletal muscle cells in response to acetylcholine binding to its receptors is called a(n)
    1. repolarizing potential.
    2. refractory period.
    3. end-plate potential.
    4. inhibitory post synaptic potential.
    5. hyperpolarizing potential.

57. The nature of a response from the sympathetic nervous system is determined by the anatomy of this system.

Describe the general structure of the sympathetic nervous system, including the three anatomical configurations and how they contribute to the overall sympathetic response.

58. The nature of a response from the parasympathetic nervous system is determined by the anatomy of this system. Describe the anatomy of the parasympathetic nervous system and how that differs from the sympathetic nervous system.
59. Acetylcholine is one of the most common neurotransmitters in the peripheral nervous system. Identify the branches of the peripheral nervous system for which acetylcholine is the neurotransmitter and describe the receptors responsible for responding to acetylcholine. Include the mechanisms whereby these receptors transduce the response to acetylcholine.
60. Norepinephrine is one of the more important neurotransmitters of the peripheral nervous system. Identify the branches of the peripheral nervous system for which norepinephrine is the neurotransmitter and

describe the receptors responsible for responding to norepinephrine. Include the mechanisms whereby these