Snell's Clinical Neuroanatomy


Review Questions

6. The following statements concern the cerebellar peduncles: (a) In the superior peduncle, most of the fibers are affer ent and arise from the neurons of the spinal cord. (b) The anterior spinocerebellar tract enters the cerebellum through the superior peduncle. (c) The inferior peduncle is made up exclusively of fibers that pass from the inferior olivary nuclei to the middle lobe of the cerebellar hemisphere. (d) The middle peduncle is formed of fibers that arise from the dentate nuclei. (e) They are surface structures that are difficult to see even by brain dissection. 7. The following statements concern the afferent fibers entering the cerebellum: (a) The mossy fibers end by making synaptic con tacts with the dendrites of the Purkinje cells. (b) They enter the cerebellum mainly through the internal and external arcuate fibers. (c) The climbing and mossy fibers constitute the two main lines of input to the cerebellar cortex. (d) They are inhibitory to the Purkinje cells. (e) They are nonmyelinated. 8. The following statements concern the functions of the cerebellum: (a) It influences the actions of muscle tendons. (b) It controls voluntary movement by coordinating the force and extent of contraction of different muscles. (c) It stimulates the contraction of antagonistic muscles. (d) It directly influences skeletal muscle activity without the assistance of the cerebral cortex. (e) It coordinates the peristaltic waves seen in intestinal muscle. 9. The following statements concern the cerebellum: (a) The afferent climbing fibers make single synap tic contacts with individual Purkinje cells. (b) The afferent mossy fibers may stimulate many Purkinje cells by first stimulating the stellate cells. (c) The neurons of the intracerebellar nuclei send axons without interruption to the opposite cere bral hemisphere. (d) The output of the cerebellar nuclei influences mus cle activity so that movements can progress in an orderly sequence from one movement to the next. (e) Past-pointing is caused by the failure of the cerebral cortex to inhibit the cerebellum after the movement has begun. 10. The following statements concern the cerebellum: (a) The cerebellar cortex has a different micro scopic structure in different individuals. (b) The axons of the Purkinje cells exert an inhibi tory influence on the neurons of the deep cere bellar nuclei. (c) Each cerebellar hemisphere principally influ ences movement on the opposite hand. (d) The part of the cerebellum that lies in the mid line is called the flocculus. (e) Intention tremor is a sign of cerebellar disease.

Directions: Matching Questions. Following thrombosis of the posterior inferior cerebellar artery, a patient pres ents the numbered signs and symptoms listed below; match the signs and symptoms with the appropriate let tered structures involved. Each lettered option may be selected once, more than once, or not at all. 11. Loss of pain and temperature on the left side of the body 12. Nystagmus 13. Hypotonicity of the muscles on the right with a ten dency to fall to the right (a) Right reticulospinal tract (b) Right inferior cerebellar peduncle (c) None of the above Directions: Match the numbered nerve tracts listed below with the lettered pathways by which they leave the cerebellum. Each lettered option may be selected once, more than once, or not at all. (a) Superior cerebellar peduncle 14. Corticopontocerebellar 15. Cuneocerebellar 16. Cerebellar reticular 17. Cerebellar rubral

(b) Corpus callosum (c) Striae medullaris (d) Inferior cerebellar peduncle (e) Middle cerebellar peduncle (f) None of the above

Directions: Each case history is followed by questions. Read the case history, then select the ONE BEST let tered answer.

A 45-year-old male with alcohol use disorder started to develop a lurching, staggering gait even when he was not intoxicated. The condition became slowly worse over a period of several weeks and then appeared to sta bilize. Friends noticed that he had difficulty in walking in tandem with another person and tended to become unsteady on turning quickly. 18. A thorough physical examination of this patient revealed the following findings, except: (a) He exhibited instability of trunk movements and incoordination of leg movements. (b) While standing still, he stood with his feet together. (c) He had no evidence of polyneuropathy. (d) Leg ataxia was confirmed by performing the heel-to-shin test. (e) Magnetic resonance imaging showed evidence of atrophy of the cerebellar vermis. 19. The following additional abnormal signs might have been observed in this patient, except: (a) Nystagmus in both eyes (b) Dysarthria (c) Tremor of the left hand when reaching for a cup (d) Paralysis of the right upper arm muscles (e) Dysdiadochokinesia Copyright © 2021 Wolters Kluwer, Inc. Unauthorized reproduction of the content is prohibited.

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