1. 13
The Peripheral Nervous System and Reflex Activity

2. ______ are stimulated when sound waves vibrate hair cells in the inner ear.
Mechanoreceptors
Thermoreceptors
Photoreceptors
Nociceptors
Answer: a. Mechanoreceptors
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3. ______ are stimulated when sound waves vibrate hair cells in the inner ear.
Mechanoreceptors
Thermoreceptors
Photoreceptors
Nociceptors
Answer: a. Mechanoreceptors
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4. Which of the following pairs of receptors appear to play complementary roles in hairy and hairless skin?
Tactile discs and lamellar corpuscles
Bulbous corpuscles and hair follicle receptors
Tendon organs and tactile corpuscles
Tactile corpuscles and hair follicle receptors
Answer: d. Tactile corpuscles and hair follicle receptors
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5. Which of the following pairs of receptors appear to play complementary roles in hairy and hairless skin?
Tactile discs and lamellar corpuscles
Bulbous corpuscles and hair follicle receptors
Tendon organs and tactile corpuscles
Tactile corpuscles and hair follicle receptors
Answer: d. Tactile corpuscles and hair follicle receptors
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6. At which level of the somatosensory system are conscious decisions made about low-grade touch stimuli?
Receptor level
Circuit level
Perceptual level
Effector level
Answer: c. Perceptual level
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7. At which level of the somatosensory system are conscious decisions made about low-grade touch stimuli?
Receptor level
Circuit level
Perceptual level
Effector level
Answer: c. Perceptual level
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8. When you first enter a movie theater, the smell of popcorn overwhelms you. Once the movie has ended, however, you don't notice the popcorn smell. You have experienced ________.
phasic sensation
tonic sensation
generator sensation
adaptation
Answer: d. adaptation
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9. When you first enter a movie theater, the smell of popcorn overwhelms you. Once the movie has ended, however, you don't notice the popcorn smell. You have experienced ________.
phasic sensation
tonic sensation
generator sensation
adaptation
Answer: d. adaptation
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10. An intensely painful stimulus is distinguished from a mildly painful one by _______.
a higher frequency of action potentials initiated
higher-magnitude action potentials
an increased number of receptors stimulated
all of the above
Answer: a. a higher frequency of action potentials
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11. An intensely painful stimulus is distinguished from a mildly painful one by _______.
a higher frequency of action potentials initiated
higher-magnitude action potentials
an increased number of receptors stimulated
all of the above
Answer: a. a higher frequency of action potentials
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12. Ganglia associated with efferent nerve fibers mostly contain cell bodies of ______.
autonomic sensory neurons
somatic sensory neurons
autonomic motor neurons
somatic motor neurons
Answer: c. autonomic motor neurons
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13. Ganglia associated with efferent nerve fibers mostly contain cell bodies of ______.
autonomic sensory neurons
somatic sensory neurons
autonomic motor neurons
somatic motor neurons
Answer: c. autonomic motor neurons
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14. The perineurium ______.
encloses all the fascicles to form a nerve
surrounds axons and Schwann cells
binds groups of fibers into bundles
contains sensory neurons only
Answer: c. binds groups of fibers into bundles
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15. The perineurium ______.
encloses all the fascicles to form a nerve
surrounds axons and Schwann cells
binds groups of fibers into bundles
contains sensory neurons only
Answer: c. binds groups of fibers into bundles
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16. CNS and PNS neurons differ in their regeneration capability, mainly because ______.
PNS neurons are associated with supporting cells that promote rapid cleanup and regrowth of new axons
CNS neurons are associated with oligodendrocytes that contain growth-inhibiting proteins
The statement is not true; neither PNS nor CNS neurons are capable of axon regeneration.
Both a and b are true.
Answer: d. Both a and b are true.
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17. CNS and PNS neurons differ in their regeneration capability, mainly because ______.
PNS neurons are associated with supporting cells that promote rapid cleanup and regrowth of new axons
CNS neurons are associated with oligodendrocytes that contain growth-inhibiting proteins
The statement is not true; neither PNS nor CNS neurons are capable of axon regeneration.
Both a and b are true.
Answer: d. Both a and b are true.
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18. Which cranial nerve is the exception and travels to the thoracic and abdominal cavities?
Trochlear
Trigeminal
Vestibulocochlear
Vagus
Answer: d. Vagus
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19. Which cranial nerve is the exception and travels to the thoracic and abdominal cavities?
Trochlear
Trigeminal
Vestibulocochlear
Vagus
Answer: d. Vagus
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20. Which of the following cranial nerves has both sensory and motor functions?
Facial
Trochlear
Hypoglossal
Accessory
Answer: a. Facial
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21. Which of the following cranial nerves has both sensory and motor functions?
Facial
Trochlear
Hypoglossal
Accessory
Answer: a. Facial
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22. The dorsal roots along the spinal cord contain _______ neurons, while the dorsal rami contain ________ neurons.
motor; motor
sensory; mixed
sensory; motor
motor; mixed
Answer: b. sensory; mixed
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23. The dorsal roots along the spinal cord contain _______ neurons, while the dorsal rami contain ________ neurons.
motor; motor
sensory; mixed
sensory; motor
motor; mixed
Answer: b. sensory; mixed
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24. Predict the outcome of damage to one cord of the left brachial plexus.
Only a portion of the left limb will suffer reduced function.
The entire left limb will be paralyzed.
The entire right limb will be paralyzed.
Only a portion of the right limb will suffer reduced function.
Answer: a. Only a portion of the left limb will suffer reduced function.
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25. Predict the outcome of damage to one cord of the left brachial plexus.
Only a portion of the left limb will suffer reduced function.
The entire left limb will be paralyzed.
The entire right limb will be paralyzed.
Only a portion of the right limb will suffer reduced function.
Answer: a. Only a portion of the left limb will suffer reduced function.
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26. If irritated, this nerve will cause hiccups.
Cervical plexus
Cutaneous nerve
Phrenic nerve
Lesser occipital nerve
Answer: c. Phrenic nerve
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27. If irritated, this nerve will cause hiccups.
Cervical plexus
Cutaneous nerve
Phrenic nerve
Lesser occipital nerve
Answer: c. Phrenic nerve
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28. A physician can determine the approximate location of a spinal injury simply by testing areas of the skin for numbness. These skin areas are referred to as ______.
dermatomes
cutaneous areas
dermozones
cutaneous zones
Answer: a. dermatomes
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29. A physician can determine the approximate location of a spinal injury simply by testing areas of the skin for numbness. These skin areas are referred to as ______.
dermatomes
cutaneous areas
dermozones
cutaneous zones
Answer: a. dermatomes
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30. For conscious muscle movements, activity of the ______ is required.
precommand areas
central program generators
reflex arc
indirect system
Answer: a. precommand areas
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31. For conscious muscle movements, activity of the ______ is required.
precommand areas
central program generators
reflex arc
indirect system
Answer: a. precommand areas
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32. Which precommand structure inhibits various motor centers of the brain?
Cerebellum
Brain stem nuclei
Spinal cord
Basal nuclei
Answer: d. Basal nuclei
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33. Which precommand structure inhibits various motor centers of the brain?
Cerebellum
Brain stem nuclei
Spinal cord
Basal nuclei
Answer: d. Basal nuclei
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34. Quickly lifting your foot and leg after stepping on a rock is an example of a(n) ________.
learned reflex
intrinsic reflex
voluntary action
central program generator
Answer: b. intrinsic reflex
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35. Quickly lifting your foot and leg after stepping on a rock is an example of a(n) ________.
learned reflex
intrinsic reflex
voluntary action
central program generator
Answer: b. intrinsic reflex
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36. The length of a muscle is communicated to the brain via a __________.
tendon organ
nociceptor
muscle spindle
lamellar corpuscle
Answer: c. muscle spindle
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37. The length of a muscle is communicated to the brain via a __________.
tendon organ
nociceptor
muscle spindle
lamellar corpuscle
Answer: c. muscle spindle
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38. A tendon reflex involves ______.
muscle contraction and shortening
muscle relaxation and lengthening
muscle contraction and lengthening
muscle relaxation and shortening
Answer: b. muscle relaxation and lengthening
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39. A tendon reflex involves ______.
muscle contraction and shortening
muscle relaxation and lengthening
muscle contraction and lengthening
muscle relaxation and shortening
Answer: b. muscle relaxation and lengthening
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40. The crossed-extensor reflex is important when ______.
someone taps on your patellar tendon
a bright light shines in your eyes
you overextend your leg during the long jump
you step barefoot on a sharp object
Answer: d. you step barefoot on a sharp object
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41. The crossed-extensor reflex is important when ______.
someone taps on your patellar tendon
a bright light shines in your eyes
you overextend your leg during the long jump
you step barefoot on a sharp object
Answer: d. you step barefoot on a sharp object
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