Bio 208 Neuroscience Exam 2 Part 3 Final

Front 1

The dorsolateral fasciculus contains axons that will:
A. cross to the opposite side of the CNS
B. ascend to the medulla before synapsing
C. synapse in laminae I and V
D. enter the ventral white commissure
E. mediate proprioceptive sensation

Back 1

C synapse in laminae I and V

Front 2

When you injure yourself, you immediately feel a sharp pain from the site of injury followed
by a throbbing painful sensation. Which of the following statements about this is FALSE:
A. the immediate pain sensation is carried by Aδ fibers
B. the immediate pain sensation travels via the lateral spinothalamic pathway
C. the throbbing pain sensation travels via the spinoreticulothalamic pathway
D. the throbbing pain sensation is mediated by the ventroposterior lateral nucleus
E. the immediate pain sensation is localized on the body by the postcentral gyrus

Back 2

D the throbbing pain sensation is mediated by the ventroposterior lateral nucleus

Front 3

Which of the following statements is NOT TRUE about the pathway that transmits
information about the emotional aspects of pain:
A. there are multiple synapses between the spinal cord and thalamus
B. it is mediated by type C fibers
C. this pathway terminates in the cingulate gyrus
D. this pathway synapses in the ventral posterior lateral thalamic nucleus
E. this pathway is part of the anterolateral system (ALS)

Back 3

D

Front 4

Damage to the spinal trigeminal nucleus on the right side of the brainstem, would result in :
A. loss of pain and temperature sensation on the ipsilateral face
B. loss of pain and temperature sensation on the contralateral face
C. loss of pain, temperature, and touch sensation on the contralatetal face
D. loss of only touch sensation on the ipsilateral face
E. loss of only touch sensation on the contralateral face

Back 4

A

Front 5

1. When a noxious stimulus is applied to a nociceptor, the receptor will discharge

1. only when the stimulus is first applied
2. when the stimulus is first applied and again when the stimulus is withdrawn
3. only while the noxious stimulus is increasing but not when it remains constant
4. as long as the noxious stimulus is present
5. any of the above, depending upon the specific nociceptive ending

Back 5

1. D. Nociceptors are (more-or-less) nonadapting

Front 6

2. Aspirin, an agent that inhibits prostaglandin synthesis, can reduce the pain of headache by

1. reducing the sensitivity of cranial nociceptors
2. reducing synaptic excitability in the spinal trigeminal nucleus
3. releasing enkephalin in the spinal trigeminal nucleus
4. depressing the thalamic intralaminar nuclei
5. preventing action potential transmission in C-fibers

Back 6

A. Aspirin is a prostaglandin synthesis inhibitor which reduces the sensitivity of nociceptive sensory endings

Front 7

3. "Phantom limb" is a example of

1. sensitization of cutaneous pain endings due to injury
2. sensory projection
3. referred pain
4. pain modulation
5. psychological hallucination

Back 7

B. It is not referred pain (choice "C") as it does not result from a stimulus to pain endings

Front 8

4. Substance P is released from

1. nociceptive afferent endings
2. first order nociceptive terminal in the dorsal horn
3. first order mechanosensitive terminals in the dorsal horn
4. terminals of descending fibers from the raphe nucleus in the dorsal horn
5. both A and B above

Back 8

e

Front 9

5. Opioid peptides are released from

1. nociceptive afferent endings
2. first order nociceptive terminal in the dorsal horn
3. first order mechanosensitive terminals in the dorsal horn
4. terminals of descending fibers from the raphe nucleus in the dorsal horn
5. both C and D above

Back 9

e

Front 10

6. Which of the following would not be expected to reduce the intensity of pain sensation?

1. electrical stimulation of the dorsal columns
2. electrical stimulation of the spinothalamic and spinoreticular tracts
3. electrical stimulation of the periaqueductal gray (PAG)
4. electrical stimulation of the raphe nucleus
5. none of the above, as all of the above would reduce pain sensation

Back 10

B. In fact, stimulating the anterolateral tracts would likely increase pain intensity

Front 11

You step on a tack with your left foot, eliciting the sensation of pain
descri[be the pathway of pain

Back 11

Sensory endings: nociceptors in the left foot; both "fast" pain (A-delta) and "slow" pain (C-fibers) endings, are depolarized (generator potential) by the noxious stimulus, causing action potentials to be generated on the axons innervating the endings. These action potentials are conducted to the spinal cord. .

Front 12

"Lateral inhibition" is a mechanism for

1. preventing excess stimulation of sensory endings
2. increasing the precision of stimulus localization
3. selectively reducing the intensity of pain sensation
4. increasing sensitivity to low intensity stimuli
5. responding to complex stimuli, such as "wetness"

Back 12

increasing the precision of stimulus localization
Lateral inhibition also increases contrast

Front 13

Pacinian corpuscles are characterized by all of the following except

1. rapid adaptation
2. axons travel in the dorsal column system
3. innervated by small myelinated axons (Ad)
4. sense rapid vibration
5. project to the somatosensory cortex

Back 13

3 Pacinian corpuscles are innervated by A-beta fibers

Front 14

When skin temperature is rapidly raised from 25 C to 35 C, the expected sequence of sensation during and after the temperature change is

1. sensation of gradual warming after the skin temperature has reached 35 C
2. initial sensation of intense warmth followed by a sensation of mild warmth
3. initial sensation of warmth followed by a rebound sensation of cold
4. no particular sensation, since cutaneous thermoreceptors are sensitive only to temperature below 25 C or above 35 C
5. no particular sensation, since at 35 C warm and cold receptors fire at the same rate

Back 14

2 Due to adaptation of the thermosensitive endings

Front 15

he spinoreticular tract is important for which of the following?

1. sensation localization
2. determining the modality of the sensation
3. cerebral cortex arousal
4. increasing sensation acuity (discrimination of detail)
5. none of the above, since the reticular formation is important in motor activity, not sensation

Back 15

3 One of the functions of the ascending reticular system is cortical arousal

Front 16

If a patient shows sensory loss at one dermatome and all ipsilateral dermatomes below it, then it is likely that the lesion is located in:

1. a peripheral nerve
2. a spinal nerve
3. a spinal root
4. the spinal cord
5. the brainstem

Back 16

4 & 5

Front 17

Coding of sensory messages is accomplished by:
a) changing the frequency of firing of action potentials.
b) changing amplitude of action potentials.
c) changing number of sensory neurons activated.
d) a and c
e) a, b and c

Back 17

D

Front 18

25. The stretch receptor neurons associated with the muscle spindle are derived from
a) mesoderm
b) neural tube
c) neural crest
d) neural UltraBrite

Back 18

C

Front 19

34. If you cut the right optic tract you would be blind in the
a) left monocular crescent only.
b) right monocular crescent only.
c) left visual field.
d) right visual field.

Back 19

c

Front 20

52. You are caught in a mosh pit and someone with big, black, clunky, Doc Martin-like shoes stomps on your foot. What is the first thing that will happen in your nervous system?
a) Action potentials carried by A-beta fibers innervating your foot will reach your CNS.
b) Action potentials carried by C fibers innervating your foot will reach your CNS.
c) Action potentials carried by A-delta fibers innervating your foot will reach your CNS.
d) An ensemble of premotor neurons in Brocas area coding for "Son of a ___" will fire.

Back 20

a

Front 21

The sensory homunculus in primary somatosensory cortex
a) is an example of placecoding.
b) reflects the variations in innervation density found in the skin of the body.
c) reflects the amount of use skin gets on different parts of the body.
d) all of the above.

Back 21

D

Front 22

You place your hand on a hot waffle iron. What happens first?
a) You feel an agonizing, aching pain.
b) You fell a stinging, sharp pain.
c) You feel the texture of the waffle iron.
d) Someone pours maple syrup on your hand and starts to eat it.

Back 22

C

Front 23

The cause of phantom limb pain is thought to involve
a) a rewiring of neuronal circuitry in the spinal cord.
b) a rewiring of neuronal circuitry in primary somatosensory cortex.
c) continued nociceptor activity in the severed limb.
d) the same mechanism responsible for referred pain

Back 23

D

Front 24

It would be great if we could not feel pain.
a) True
b) False

Back 24

B

Front 25

You wake up one morning to discover that you have lost the ability to make fine finger movements, but you can move your hand and arm. Where might the damage be that is causing this problem?
a) corticospinal tract
b) spinothalamic tract
c) rubrospinal tract
d) medial lemniscus
e) ventromedial pathway

Back 25

A

Front 26

Your roommate wakes up on the same morning to discover that he/she has lost the ability to sit upright, but has no problem with fine finger movements. Where might the damage be that is causing this problem?
a) corticospinal tract
b) spinothalamic tract
c) rubrospinal tract
d) medial lemniscus
e) ventromedial pathway

Back 26

E