Neurobiology Ch 10 Dashboard Q's

In terms of conduction velocity, the axons arising from peripheral nociceptors
a. are the fastest conducting nerve fibers.
b. are the second fastest group of fibers, slower only than muscle and joint proprioceptors.
c. are the third fastest group of fibers, being slower than the group I and II sensory afferents.
d. include the slowest-conducting of the peripheral sensory afferents.
e. are of indeterminate conduction velocity.

D

The bundle of central branches of pain-sensitive dorsal root ganglion cells forms
a. Rexed's laminae 1 and 5.
b. Lissauer's tract.
c. the medial dorsal column.
d. the lateral dorsal column.
e. the anterolateral tract.

B

A loss of tactile, pain, and temperature sensations localized to the lower right leg would most likely be the result of
a. injury to the right side of the lower spinal cord.
b. injury to the left side of the lower spinal cord.
c. bilateral spinal cord injury at lower spinal levels.
d. right peripheral nerve damage.
e. left peripheral nerve damage.

D

A 32-year old male presents with a wound that has caused left hemisection of the spinal cord at T10. Which sensory loss would you expect to find?
a. Contralateral loss of touch and proprioception below the level of the lesion; ipsilateral loss of pain and temperature below the level of the lesion
b. Contralateral loss of touch, proprioception, pain, and temperature below the level of the lesion
c. Ipsilateral loss of touch and proprioception below the level of the lesion; contralateral loss of pain and temperature below the level of the lesion
d. Ipsilateral loss of touch, proprioception, pain, and temperature below the level of the lesion
e. Ipsilateral and contralateral loss of touch, proprioception, pain, and temperature below the level of the lesion

C

Referred pain
a. denotes the symptoms of patients who have been referred from a general practice physician to a pain management specialist.
b. results when cutaneous sensory neurons send aberrant axonal branches to visceral organs.
c. results when visceral neurons send aberrant axonal branches to the skin.
d. arises from the conveyance of both visceral and cutaneous pain information by dorsal horn neurons.
e. results when mechanosensation neurons, but not pain neurons, from the same location on the body have been damaged.

D

Which structure plays the largest role in the sensory-discriminative aspects of pain, as opposed to its affective aspects?
a. Amygdala
b. Periaqueductal gray
c. Ventral posterior lateral nucleus of the thalamus
d. Midline thalamic nuclei
e. Anterior cingulate cortex

C

In a neuroscience experiment examining the effect of hypnosis on pain perception, subjects were first poked in the hand with a sharp probe and asked to rate the pain on a 1 (no pain) to 5 (intense pain) scale. Researchers noted how much pressure it took to elicit pain at both a level 2 and a level 4. Subjects were then hypnotized and scanned using fMRI. During fMRI evaluation, subjects were poked with the sharp probe with enough pressure to elicit level 2 pain. Without changing the intensity of the pressure, researchers then persuaded subjects that the pressure was increasing during the fMRI measurements. In what brain region would you expect to see increases in activity in the hypnotized subjects?
a. Hippocampus
b. Somatosensory cortex
c. Ventral posterior nucleus of the thalamus
d. Anterior cingulate
e. No region would change in activity

D

Facial pain and temperature sensations are conveyed
a. by large-diameter, heavily myelinated axons.
b. by neurons located in the dorsal root ganglia.
c. by axons that enter the pons and descend to the medulla.
d. to the thalamus by ipsilaterally projecting reticulothalamic neurons.
e. All of the above

C

Terry is diagnosed with a lesion that damaged the right ventral posterior medial nucleus of the thalamus. What symptoms would you expect Terry to show?
a. Loss of pain and temperature sensation from stimuli to the right side of the face
b. Loss of pain and temperature sensation from stimuli to the right side of the body
c. Loss of pain and temperature sensation from stimuli to the left side of the face
d. Loss of pain and temperature sensation from stimuli to the left side of the body
e. Loss of pain and temperature sensation from stimuli to the both right and left side of the face

C

Nondiscriminative touch
a. refers to the capacity to tactically sense things but with little two-point discrimination or ability to identify objects.
b. is the tactile sensing pathway with the highest spatial resolution.
c. refers to the sensation of objects via their painful and burning qualities.
d. is mediated by second-order fibers that cross in the medulla and project directly to cingulate cortex.
e. enables excellent object identification in cases of dorsal column injuries.

A

Peripheral sensitization
a. occurs only after repeated injuries to a particular portion of the body.
b. is distinguished from hyperalgesia, in that it mainly concerns pleasant stimuli.
c. involves an "inflammatory soup" of histamine, prostaglandins, and many other compounds.
d. involves the enhancement of such mechanoreceptors as the Pacinian and Meissner corpuscles.
e. All of the above

C

You hit your thumb with a hammer and immediately grab your finger and squeeze the injured area. The pain subsides slightly. Activation of what type of neuron is responsible for the reduction in pain sensation?
a. A mechanoreceptor afferents
b. Descending enkephalin efferents
c. C fibers afferents
d. Ia proprioceptive afferents
e. Dorsal horn projection neurons

A

The pathways that descend into the spinal cord and modulate pain transmission via direct influences on the dorsal horn arise from all areas except the
a. parabrachial nucleus.
b. periaqueductal gray.
c. dorsal raphe.
d. locus coeruleus.
e. medullary reticular formation.

B

Logan has been managing chronic pain in his leg and back from bike accident injuries for over a year. His doctor has suggested that they stimulate his brain in an attempt to relieve some of the pain. Stimulation of which region would be most likely to produce relief?
a. Periaqueductal gray
b. Somatosensory cortex
c. Anterior cingulate
d. Ventral posterior medial nucleus of the thalamus
e. Superior colliculus

A