Neuroscience VI

Question 1

Which cranial nerve is responsible for the efferent limb of the gag reflex?

Answer 1

CN X

Question 2

Which cranial nerve nuclei (4) are located medially?

Answer 2

III, IV, VI, and XII

“factors of 12, except 1 and 2”

Question 3

Which cranial nerves (2) are NOT located in the brain stem?

Answer 3

I and II

some sources also include CN XI in this list

Question 4

Which cranial nerves (4) are located above the pons?

Answer 4

I, II, III, and IV

note: CN I and II are not located in the brain stem; III and IV are in the midbrain

Question 5

Which cranial nerves (4) are located in the medulla?

Answer 5

IX, X, XI*, and XII

CN XI is located proximal, but not within, the medulla, thus intramedullary lesions do not affect the spinal accessory nerve

Question 6

Which cranial nerves (4) are located in the pons?

Answer 6

V, VI, VII, and VIII

Question 7

Which part of the basal ganglia sends dopaminergic neurons to the striatum to alter activity of both basal ganglia pathways?

Answer 7

Substantia nigra

Question 8

Which part of the brainstem contains the nuclei of CN III and IV?

Answer 8

Midbrain

CN III nucleus in rostral midbrain; CN IV nucleus in caudal midbrain

Question 9

Which part of the brainstem contains the nuclei of CN IX, X and XII?

Answer 9

Medulla

Question 10

Which part of the brainstem contains the nuclei of CN V, VI, VII and VIII?

Answer 10

Pons

Question 11

Which peripheral nerve layer must be rejoined in microsurgery for limb attachment?

Answer 11

Perineurium

Question 12

Which stage of sleep do young adults spend the most time in?

Answer 12

Stage N2 (45%)

N2 (45%) > N3 and REM (25% each) > N1 (5%)

Question 13

Which stage of sleep does bedwetting occur?

Answer 13

Stage N3

Question 14

Which stage of sleep does bruxism (teeth grinding) occur?

Answer 14

Stage N2

Question 15

Which thalamic nuclei (2) receive motor input from the basal ganglia and cerebellum?

Answer 15

Ventral anterior (VA) / Ventral lateral (VL)

Question 16

Which thalamic nucleus receives auditory input from the inferior colliculus and superior olive?

Answer 16

Medial geniculate body (MGB)

“medial = music”

Question 17

Which thalamic nucleus receives input from the spinothalamic tract and dorsal columns?

Answer 17

Ventral posterolateral (VPL)

thus receives sensations of pain, temperature, pressure, touch, vibration, proprioception

Question 18

Which thalamic nucleus receives input from the trigeminal nerve and gustatory pathway?

Answer 18

Ventral posteromedial (VPM)

thus receives face sensation and taste; “Makeup goes on the face (VPM)”

Question 19

Which thalamic nucleus receives visual input from CN II?

Answer 19

Lateral geniculate body (LGB)

“lateral = light”

Question 20

Which type of sensory receptor senses pain and temperature?

Answer 20

Free nerve endings (e.g. C, Aδ)

Question 21

Within the ventral horn, alpha and gamma motoneurons that innervate extensors are located more […].

Answer 21

Within the ventral horn, alpha and gamma motoneurons that innervate extensors are located more ventrally.

Question 22

Within the ventral horn, alpha and gamma motoneurons that innervate flexors are located more […].

Answer 22

Within the ventral horn, alpha and gamma motoneurons that innervate flexors are located more dorsally.

Question 23

Within the ventral horn, alpha and gamma motoneurons that innervate more distal structures are located […].

Answer 23

Within the ventral horn, alpha and gamma motoneurons that innervate more distal structures are located laterally.

Question 24

Within the ventral horn, alpha and gamma motoneurons that innervate more proximal structures are located […].

Answer 24

Within the ventral horn, alpha and gamma motoneurons that innervate more proximal structures are located medially.

Question 25

[...] is a higher-order language deficit (inability to understand, speak, read, and/or write).

Answer 25

**Aphasia** is a higher-order language deficit (inability to understand, speak, read, and/or write).

Question 26

[...] neurons within the striatum stimulate the indirect basal ganglia pathway.

Answer 26

**Cholinergic** neurons within the striatum stimulate the indirect basal ganglia pathway. thus inhibiting movement

Question 27

[...] are structures in the brain that are characterized by extensive vasculature and lack of blood-brain-barrier.

Answer 27

**Circumventricular organs (CVOs)** are structures in the brain that are characterized by extensive vasculature and lack of blood-brain-barrier. CVOs allow for the linkage between the central nervous system and peripheral blood flow; e.g. area postrema, OVLT

Question 28

[...] tracts serve as a source of UMN innervation of LMNs in cranial nerve nuclei.

Answer 28

**Corticobulbar** tracts serve as a source of UMN innervation of LMNs in cranial nerve nuclei. influence all brain stem nuclei that innervate skeletal muscle (e.g. CN V, VII, X, XI, XII)

Question 29

[...] is a motor inability to speak.

Answer 29

**Dysarthria** is a motor inability to speak.

Question 30

[...] of the globus pallidus internus results in inhibition of the ipsilateral ventral lateral (VL) nucleus of the thalamus (basal ganglia pathway).

Answer 30

**Excitation** of the globus pallidus internus results in inhibition of the ipsilateral ventral lateral (VL) nucleus of the thalamus (basal ganglia pathway). i.e. indirect basal ganglia pathway

Question 31

[...] is the main inhibitory neurotransmitter of the CNS.

Answer 31

**GABA** is the main inhibitory neurotransmitter of the CNS.

Question 32

[...] is the main excitatory neurotransmitter of the CNS.

Answer 32

**Glutamate** is the main excitatory neurotransmitter of the CNS.

Question 33

[...] is the main inhibitory neurotransmitter of the spinal cord.

Answer 33

**Glycine** is the main inhibitory neurotransmitter of the spinal cord.

Question 34

[...] frequencies are best heard at the base of the basilar membrane.

Answer 34

**High** frequencies are best heard at the base of the basilar membrane.

Question 35

[...] of the globus pallidus internus results in excitation of the ipsilateral ventral lateral (VL) nucleus of the thalamus (basal ganglia pathway).

Answer 35

**Inhibition** of the globus pallidus internus results in excitation of the ipsilateral ventral lateral (VL) nucleus of the thalamus (basal ganglia pathway). i.e. direct basal ganglia pathway

Question 36

[...] frequencies are best heard at the apex of the basilar membrane (near the helicotrema).

Answer 36

**Low** frequencies are best heard at the apex of the basilar membrane (near the helicotrema).

Question 37

[...] is aging-related impaired accomodation.

Answer 37

**Presbyopia** is aging-related impaired accomodation.

Question 38

[...] aphasia is caused by damage to the areas around Broca's area; Broca's area itself is spared.

Answer 38

**Transcortical motor** aphasia is caused by damage to the areas around Broca's area; Broca's area itself is spared.

Question 39

[...] aphasia is caused by damage to the areas around Wernicke's area; Wernicke's area itself is spared.

Answer 39

**Transcortical sensory** aphasia is caused by damage to the areas around Wernicke's area; Wernicke's area itself is spared.

Question 40

[...] motoneurons provide descending control over reflexes.

Answer 40

**Upper** motoneurons provide descending control over reflexes.

Question 41

Blockage of the mesocortical dopamine pathway results in increased "[...]" symptoms of schizophrenia.

Answer 41

Blockage of the mesocortical dopamine pathway results in increased "**negative**" symptoms of schizophrenia. e.g. anergia, apathy, lack of spontaneity

Question 42

[...] of the mesocortical dopamine pathway results in increased "negative" symptoms of schizophrenia.

Answer 42

**Blockage** of the mesocortical dopamine pathway results in increased "negative" symptoms of schizophrenia. e.g. anergia, apathy, lack of spontaneity

Question 43

Blockage of the nigrostriatal dopamine pathway results in increased [...] symptoms.

Answer 43

Blockage of the nigrostriatal dopamine pathway results in increased **extrapyramidal** symptoms. e.g. dystonia, akathisia, parkinsonism, tardive diskinesia; seen with dopamine antagonists

Question 44

[...] of the nigrostriatal dopamine pathway results in increased extrapyramidal symptoms.

Answer 44

**Blockage** of the nigrostriatal dopamine pathway results in increased extrapyramidal symptoms. e.g. dystonia, akathisia, parkinsonism, tardive diskinesia; seen with dopamine antagonists

Question 45

Blockage of the tuberoinfundibular dopamine pathway results in symptoms of [...] excess.

Answer 45

Blockage of the tuberoinfundibular dopamine pathway results in symptoms of **prolactin** excess. e.g. decreased libido, sexual dysfunction, galactorrhea, gynecomastia (men)

Question 46

[...] of the tuberoinfundibular dopamine pathway results in symptoms of prolactin excess.

Answer 46

**Blockage** of the tuberoinfundibular dopamine pathway results in symptoms of prolactin excess. e.g. decreased libido, sexual dysfunction, galactorrhea, gynecomastia (men)

Question 47

Stimulation of the mesolimbic dopamine pathway results in increased "[...]" symptoms of schizophrenia.

Answer 47

Stimulation of the mesolimbic dopamine pathway results in increased "**positive**" symptoms of schizophrenia. e.g. delusions, hallucinations; thus, blockage of this pathway (anti-psychotics) relieves symptoms

Question 48

[...] of the mesolimbic dopamine pathway results in increased "positive" symptoms of schizophrenia.

Answer 48

**Stimulation** of the mesolimbic dopamine pathway results in increased "positive" symptoms of schizophrenia. e.g. delusions, hallucinations; thus, blockage of this pathway (anti-psychotics) relieves symptoms