BRS

Answers and Explanations

1. D. The ventral lateral nucleus receives motor input from the extrapyramidal (striatal) motor sys tem (globus pallidus and substantia nigra) and from the cerebellum (dentate nucleus). 2. D. Spinothalamic fibers project to the VPL nucleus, which receives the medial lemniscus. 3. D. Cerebellar fibers project to the ventral lateral (primarily) and VPL nuclei, which in turn project to the motor cortex (area 4). 4. B. The globus pallidus, a nucleus of the extrapyramidal (striatal) motor system, projects to three thalamic nuclei: the centromedian, the ventral anterior, and the ventral lateral nuclei of the thalamus. 5. A. Radioactive label is found in the anterior nucleus of the thalamus, which receives input from the mammillary nuclei via the mammillothalamic tract. The arcuate nucleus of the hypothala mus projects to the portal vessels of the infundibulum via the tuberohypophyseal (tuberoinfun dibular) pathway; the ventral anterior nucleus of the thalamus receives input from the globus pallidus and the substantia nigra; the dorsomedial nucleus of the thalamus receives input from the amygdala, temporal neocortex, and substantia nigra; and the supraoptic nucleus of the hy pothalamus synthesizes vasopressin and oxytocin and projects to the pituitary gland. 6. D. Infarction of the internal capsule gives rise to contralateral symptoms. Thus, infarction to the right internal capsule would result in left-sided symptoms, including tactile hypesthesia, con tralateral anesthesia, contralateral hemiparesis (with Babinski sign), contralateral lower facial weakness, and contralateral homonymous hemianopia. 7. C. A capsular stroke is most commonly caused by occlusion of the lateral striate branches of the middle cerebral artery. 8. I. The VPM nucleus receives taste input via the ipsilateral central tegmental tract. The VPM nu cleus receives sensory input from the head and oral cavity. 9. E. The pulvinar, the largest thalamic nucleus, has reciprocal connections with the inferior pari etal lobule. Pulvinar is often considered as part of the pulvinar–LP system because of the inter connectedness of the nuclei. 10. H. The VPL nucleus receives input from the contralateral lateral spinothalamic tract, part of the anterolateral system. 11. B. The centromedian nucleus projects to the putamen; this thalamic nucleus also has reciprocal connections with the motor cortex. 12. G. The ventral lateral nucleus receives contralateral cerebellar input via the dentatorubrotha lamic tract. 13. D. The mediodorsal nucleus plays a role in the expression of affect, emotion, and behavior (lim bic function). It receives input from the amygdala and has reciprocal connections with the pre frontal cortex. Lesions of the mediodorsal nucleus are found in patients with Korsakoff amnestic state. 14. B. The MGB receives auditory input via the brachium of the inferior colliculus. 15. E. The ventral lateral nucleus receives input from the globus pallidus via the thalamic fasciculus. 16. A. The anterior nucleus receives input from the mammillary nuclei via the mammillothalamic tract. This is a major link in the Papez circuit. 17. E. The ventral lateral nucleus receives cerebellar input from the dentate nucleus via the denta torubrothalamic tract. 18. D. The VPM nucleus receives SVA (taste) fibers via the central tegmental tract.

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