This program was provided by the Univ. of Missouri Dept. of Anatomy 1. The cerebral aqueduct connects the lateral ventricle to the third ventricle the fourth ventricle to lateral cisterns the third ventricle to the fourth ventricle the fourth ventricle to the cisterna magna none of the above Correct! incorrect because this is the foramen of Monro or interventricular foramen incorrect because this is the foramen of Lushka incorrect because this is the foramen of Magendie No. The answer is C. The cerebral aqueduct also called the aqueduct of Sylvius connects the third ventricle to the fourth ventricle. 2. The interventricular foramen connects Correct! the foramen of Monro or interventricular foramen is correct incorrect, The cerebral aqueduct also called the aqueduct of Sylvius connects the third ventricle to the fourth ventricle. incorrect because this is the foramen of Lushka incorrect because this is the foramen of Magendie No. The answer is A. 3. The foramen of Lushka connects Correct! incorrect because this is the foramen of Monro or interventricular foramen incorrect, The cerebral aqueduct also called the aqueduct of Sylvius connects the third ventricle to the fourth ventricle. incorrect because this is the foramen of Magendie No. The answer is B. 4. The foramen of Magendie connects Correct! incorrect because this is the foramen of Monro or interventricular foramen incorrect because this is the foramen of Lushka incorrect, The cerebral aqueduct also called the aqueduct of Sylvius connects the third ventricle to the fourth ventricle. No. The answer is D. 5. The choroid plexus is found in the lateral ventricle the fourth ventricle the third ventricle all of the above none of the above Correct! No. The answer is D. The choroid plexus is found in all three ventricles with the lateral ventricles being the most important source of CSF production. 6. The superior colliculus is a pontine structure a midbrain structure a medulla structure a telencephalic structure none of the above Correct! No. The answer is B. The superior colliculus sits on top of the midbrain, the most anterior two bumps of the quadrigeminal plate, with the posterior two bumps called the inferior colliculi. 7. The pyramids are Correct! No. The answer is C. The pyramids are located on the ventral aspect of the medulla on either side of the midline, and as you will learn later contain the corticospinal tracts involved with voluntary movement. 8. The trigeminal nerve (cranial nerve five) exits from the midbrain pons medulla spinal cord none of the above Correct! No. The answer is B. The trigeminal nerve exits at a mid-pontine level of the brainstem. 9. The vagus nerve (cranial nerve 10) exits from the Correct! No. The answer is C. The vagus nerve exits from the medulla just ventral to the tuber cinereum on the lateral side of the brainstem. 10. The hypoglossal nerve exits from the Correct! No. The answer is C. The hypoglossal nerve exits from the medulla just ventral to the olive in the ventrolateral sulcus. 11. The trochlear nerve exits from the Correct! No. The answer is A. The trochlear nerve is the only cranial nerve to exit from a dorsal site, just posterior to the inferior colliculi of the midbrain. 12. Which is the only cranial nerve to exit from the dorsal aspect of the brainstem vagus trigeminal trochlear hypoglossal none of the above Correct! No. The answer is C. The trochlear nerve is the only cranial nerve to exit from a dorsal site, just posterior to the inferior colliculi of the midbrain. 13. Which is the only cranial nerve to exit from the preolivary sulcus Correct! No. The answer is D. The HYPOGLOSSAL nerve is the only candidate ! 14. Which cranial nerve exits at the pontomedullary junction abducens trigeminal trochlear hypoglossal none of the above Correct! No. The answer is A. The ABDUCENS exists at this junction, but what other two cranial nerves also exit at this level ? 15. Which cranial nerve exits from mid-pons Correct! No. The answer is B. The TRIGEMINAL is the only cranial nerve to exit from mid-pons. This is an important landmark to remember when we undertake diagnostic localization of lesions affecting the brainstem. 16. Which is an unpaired brain structure olive fornix pyramid pineal none of the above Correct! No. The answer is D. There is only one pineal body of the midbrain, all the other structures are paired on both sides of the brain. Of course the septum pellucidum and infundibulum are also unpaired. 17. The lateral fissure or sulcus separates the precentral from the postcentral gyrus is also called the Sylvian fissure separates parietal from temporal lobes both B and C none of the above Correct! No. The answer is D. The lateral fissure, also called the Sylvian fissure separates the parietal from the temporal lobes. 18. The transverse cerebral fissure separates the precentral from the postcentral gyrus is also called the Sylvian fissure separates parietal from temporal lobes separates the occipital lobes from the cerebellum none of the above Correct! No. The answer is D. The transverse cerebral fissure is where the tentorium cerebelli normally would reside separating the occipital lobes of the cerebral hemisphere from the cerebellum. 19. The gyrus lying immediately ventral to the lateral fissure is middle temporal gyrus precentral gyrus superior temporal gyrus inferior frontal gyrus none of the above Correct! No. The answer is C. The SUPERIOR TEMPORAL GYRUS lies just ventral to the lateral fissure. 20. The medial gyrus lying immediately dorsal to the corpus callosum is medial frontal gyrus precentral gyrus cingulate gyrus inferior frontal gyrus none of the above Correct! No. The answer is C. The CINGULATE GYRUS lies just dorsal to the corpus callosum and is seen in the midsaggital plane. 21. The area found anterior and adjacent to the parieto-occipital sulcus on the medial surface is medial frontal gyrus precuneus cingulate gyrus cuneus none of the above Correct! No. The answer is B. The PRECUNEUS is the only structure on the medial surface which is found anterior and adjacent to the parieto-occipital sulcus. 22. The gyrus located on the ventro-medial surface lying medial to the olfactory sulcus is medial frontal gyrus gyrus rectus cingulate gyrus cuneus none of the above Correct! No. The answer is B. Gyrus rectus is the only ventral-medial gyrus of the possible answers. 23. The callosal sulcus lies immediately ventral to the medial frontal gyrus parahippocampal gyrus cingulate gyrus paracentral lobule none of the above Correct! No. The answer is C. The callosal sulcus is dorsal to the corpus callosum separating it from the cingulate gyrus. 24. The calcarine sulcus separates the cingulate gyrus from the superior frontal gyrus cuneus from the lingual gyrus cuneus from precuneous precentral gyrus from postcentral gyrus none of the above Correct! incorrect because it would be the cingulate gyrus incorrect because it would be the parieto-occipital sulcus incorrect because it would be the central sulcus No. The answer is B. 25. The parieto-occipital sulcus separates Correct! incorrect because it would be the cingulate gyrus incorrect because it would be the calcarine sulcus incorrect because it would be the central sulcus No. The answer is C. 26. The structure lying in the interhemispheric fissure is the falx cerebri cuneus gyrus rectus tentorium cerebeli none of the above Correct! No. The answer is A. The only structure lying in the interhemispheric fissure is the falx cerebri, the other answers are structures which are on the medial surface, or not in the interhemispheric fissure (answer D). 27. What is the name of the bump or swelling seen lying medial to the parahippocampal gyrus lingual gyrus uncus inferior temporal gyrus orbital gyri none of the above Correct! No. The answer is B. The only structure lying medial to the parahippocampal gyrus which is a distinctive bump is the uncus which contains the amygdaloid nucleus within it. 28. Gyrus breves is in the lingual gyrus insular cortex inferior temporal gyrus orbital gyri none of the above Correct! No. The answer is B. The gyrus breves and longus as well as the limen insulae are found buried deep within the cerebral cortex in the insula or island of Reil which is concealed from observation by the frontal, parietal and temporal opercula which must be spread apart in order to expose the insula. This has been done on a demonstration specimen in the laboratory. 29. The terminal vein is in the midline interhemispheric fissure between the thalamus and the body of the caudate nucleus lateral and dorsal to the body of the caudate nucleus adjacent to the mammillary bodies none of the above Correct! No. The answer is B. The terminal vein also called the thalamostriate vein is located medial and ventral to the body of the caudate lying adjacent to stria terminalis and is situated between the thalamus and caudate nucleus (also called striatum). 30. The stria terminalis is in the midline interhemispheric fissure medial and ventral to the body of the caudate nucleus lateral and dorsal to the body of the caudate nucleus adjacent to the mammillary bodies none of the above Correct! No. The answer is B. The stria terminalis and the terminal vein also called the thalamostriate vein is located medial and ventral to the body of the caudate. 31. The dentate gyrus is adjacent to the midline interhemispheric fissure medial and posterior to the tail of the caudate nucleus anterior to the putamen dorsal to the corpus callosum none of the above Correct! No. The answer is B. The dentate gyrus lies under the fimbria in the hippocampal formation and is medial and posterior to the tail of the caudate nucleus which is best seen in a horizontal section. 32. The claustrum is medial to the globus pallidus medial to the putamen both A and B lateral to the extreme capsule none of the above Correct! No. The answer is E. The claustrum is lateral to both the globus pallidus and putamen, and is medial to the extreme capsule, so none of the above answers are correct. 33. The external capsule is medial to the globus pallidus medial to the putamen medial to the claustrum lateral to the extreme capsule none of the above Correct! No. The answer is C. The external capsule is immediately medial and adjacent to the claustrum. 34. The internal capsule is lateral to the globus pallidus lateral to the external capsule lateral to the claustrum all of the above none of the above Correct! No. The answer is E. The internal capsule is medial to all of these structures. 35. The putamen is lateral to the extreme capsule lateral to the external capsule lateral to the claustrum lateral to the globus pallidus none of the above Correct! No. The answer is D. The putamen is only lateral to the globus pallidus, all the other structures are lateral to the putamen. 36. The stria terminalis is ventral to the globus pallidus dorso-medial to the globus pallidus lateral to the claustrum both A and B none of the above Correct! No. The answer is D. The stria terminalis is found in two places in a coronal section, both ventral to the globus pallidus and dorso-medial to the globus pallidus because it is a c-shaped structure curving together with the body and tail of the caudate nucleus. 37. The insular cortex is adjacent to the extreme capsule adjacent to the external capsule adjacent to the internal capsule lateral to the claustrum none of the above Correct! No. The answer is A. The insular cortex is immediately lateral and adjacent to the extreme capsule. 38. The dorsal median sulcus is adjacent to fasciculus cuneatus is adjacent to fasiculus gracilis is lateral to the dorsolateral sulci is is the same as the dorsal funiculus none of the above Correct! No. The answer is B. The dorsal median sulcus is immediately adjacent to fasciculus gracilis, and is medial to the dorsolateral sulci. Remember a sulcus is a groove or trough, whereas a funiculus or fasciculus is a portion of spinal cord defined by sulci or fissures. 39. The dorsal funiculus includes fasciculus gracilis fasciculus cuneatus dorsolateral tract of Lissauer dorsal median sulcus all of the above Correct! No. The answer is E. The dorsal funiculus includes both the fasciculus gracilis and the fasciculus cuneatus, the dorsal median sulcus and the dorsolateral tract of Lissauer. 40. The arachnoid adheres to the spinal cord is the outermost layer of meninges lies against the inner surface of dura lies against the outer surface of dura none of the above Correct! No. The answer is C. The arachnoid lies against the inner surface of the dura and forms the outer boundary of the fluid filled subarachnoid space. What fluid fills the subarachnoid space normally ? Correct, cerebrospinal fluid, not blood. The presence of blood in the subarachnoid space is a pathological sign suggesting subarachnoid hemorrhage. a, is incorrect because pia mater adheres directly to the spinal cord. 41. The vagal trigone is lateral to the vestibular area is lateral to the hypoglossal trigone is medial to the hypoglossal trigone lies anterior to striae medullares none of the above Correct! No. The answer is B. The vagal trigone is lateral to the hypoglossal trigone , medial to the vestibular area and posterior to striae medullares. 42. The medial eminence Correct! No. The answer is D. The medial eminence is anterior to striae medullares and medial to the vestibular area. 43. The sulcus which separates medial eminence from vestibular area is striae medullares dorsal median sulcus sulcus limitans preolivary sulcus none of the above Correct! No. The answer is C. The sulcus limitans forms the anterior posterior boundary between the medial eminence and the vestibular area. 44. The structure forming the anterior roof of the fourth ventricle is superior medullary velum hypoglossal trigone vagal trigone both B and C none of the above Correct! No. The answer is A The superior medullary velum forms the anterior roof of the fourth ventricle,the other structures in this answer are located on the floor of the fourth ventricle. 45. The floor of the fourth ventricle is composed of vestibular area hypoglossal trigone vagal trigone all of the above none of the above Correct! No. The answer is D. The floor of the fourth ventricle is composed from the hypoglossal and vagal trigones as well as the vestibular area. 46. The habenula is part of the dorsal thalamus epithalamus hypothalamus pons none of the above Correct! No. The answer is B. The habenula including the trigone and habenular commissure is part of the epithalamus. Remember epi means above something, and in this case these structures are above or dorsal to the thalamus. 47. The posterior commissure is part of the Correct! No. The answer is B. The posterior commissure,habenula including the trigone and habenular commissure are all part of the epithalamus. Remember epi means above the thalamus and these structures are dorsal to the thalamus. 48. The massa intermedia is part of the Correct! No. The answer is A. The massa intermedia or thalamic adhesion is found on the medial surface opposite the thalamus and looks like it connects the two sides of the brain together, but this is not the case as it may be present in only 70% of brains examined. It is part of the dorsal thalamus. 49. The infundibulum is part of the Correct! No. The answer is C. The infundibulum is part of the hypothalamus and forms a stock by which releasing hormones from the hypothalamus reach the pituitary gland. 50. The pulvinar is part of the Correct! No. The answer is A. The pulvinar is part of the dorsal thalamus even though it dosen't have a thalamic sounding name. It is one of the most posterior thalamic nuclei and sends information to the occipital cortex. 51. The motor nuclei are located in the dorsal funiculus lateral funiculus ventral funiculus ventral gray horn none of the above Correct! No. The answer is D. The motor nuclei are located in the ventral gray horn, all of the other answers are white matter which consists of tracts, ie axons of neurons rather than cell bodies which compose the motor nuclei. 52. The lateral corticospinal tract is located in the dorsal funiculus dorsolateral funiculus ventral funiculus ventral gray horn none of the above Correct! No. The answer is B. The lateral corticospinal tract is a descending motor pathway located in the dorsolateral funiculus. 53. The vestibulospinal tract is located in the Correct! No. The answer is C. The vestibulospinal tract is a descending motor tract playing a major role in posture and balance and is located in the ventral funiculus. 54. The dorsal spinocerebellar tract is located in the Correct! No. The answer is B. The dorsal spinocerebellar tract is an afferent pathway carrying proprioceptive information from the lower limbs and is located in the dorsolateral funiculus. 55. The fasciculus gracilis is located in the Correct! No. The answer is A. The fasciculus gracilis is an ascending sensory tract carrying cutaneous information from the lower limbs to nucleus gracilis in the medulla and it is found in the dorsal funiculus. 56. Nucleus dorsalis is found below L1 above L1 lateral to the dorsal spinocerebellar tract ventral to rubrospinal tract none of the above Correct! No. The answer is B. Nucleus dorsalis, also called Clarke's nucleus is apparent from L1 to C8 and is an important relay nucleus for proprioceptive information from the lower limb. 57. A large gray to white matter ratio is found in sacral cord lumbar cord thoraic cord cervical cord none of the above Correct! No. The answer is A. Only the sacral cord has the large gray to white matter ratio due to the large number of neuronal cell bodies and a paucity of tracts. 58. The dorsal intermediate sulcus separates fasciculus cuneatus from the dorsolateral tract fasciculus gracilis from fasciculus cuneatus dorsal spinocerebellar from the ventral spinocerebellar tract lateral corticospinal from rubrospinal tract none of the above Correct! No. The answer is B. Fasiculus cuneatus is separated from faciculus gracilis by the dorsal intermediate culcus. This may be seen on the wet specimens and the slides, but only above what level of the cord ? 59. The spinal cord tract lying adjacent to the ventral median fissure is ventral corticospinal tract fasciculus gracilis ventral spinocerebellar tract lateral corticospinal none of the above Correct! No. The answer is A. The ventral corticospinal tract is the only tract adjacent to the ventral median fissure from the above answers, although the MLF which contains the medial vestibulospinal tract is very close to this fissure. 60. The tract lying just medial to the dorsal spinocerebellar tract is Correct! No. The answer is D. The lateral corticospinal tract is just medial to the dorsal spinocerebellar tract. Is this tract motor or sensory ? 61. The tract lying immediately ventral to the ventral spinothalamic tract is ventral corticospinal tract vestibulospinal tract ventral spinocerebellar tract lateral corticospinal none of the above Correct! No. The answer is B. The vestibulospinal tract lies immediately ventral to the ventral spinothalamic tract. Is this tract motor or sensory ? 62. The tract lying immediately ventral to the lateral corticospinal tract is ventral corticospinal tract lateral vestibulospinal tract ventral spinocerebellar tract rubrospinal tract none of the above Correct! No. The answer is D. The rubrospinal tract lies immediately ventral to the lateral corticospinal tract.Where does the rubrospinal tract originate ? 63. The tract lying lateral to the lateral spinothalamic tract is Correct! No. The answer is C. The ventrospinocerebellar tract lies lateral to the lateral spinothalamic tract.Is this tract motor or sensory ? 64. The pyramidal decussation occurs in the upper medulla upper pons lower medulla lower pons none of the above Correct! No. The answer is C. The pyramidal decussation occurs in the lower medulla at the point where the spinal cord begins. It is a classic marker especially on slides for the level you are looking at ! Where does the pyramidal decussation lie in relation to external anatomy ? At the level of the foramen magnum, where the spinal cord begins, right ? 65. What lies just medial to the spinal tract of V lateral spinothalamic tract rubrospinal tract spinal trigeminal nucleus accessory nucleus none of the above Correct! No. The answer is C. The spinal trigeminal nucleus of V lies just medial to the spinal tract of V for the entir extent of the medulla. 66. The most medial cranial nerve nucleus in mid-medulla is nucleus gracilis dorsal motor nucleus of vagus hypoglossal nucleus accessory nucleus none of the above Correct! No. The answer is C. The hypoglossal nucleus is the most medial cranial nerve nucleus throughout the extent of the medulla. 67. The cranial nerve nucleus lying just lateral to hypoglossal is nucleus gracilis dorsal motor nucleus of vagus medial lemniscus accessory nucleus none of the above Correct! No. The answer is B. The dorsal motor nucleus of the vagus is just lateral to the hypoglossal nucleus. Note that nucleus gracilis and medial lemniscus are not cranial nerve nuclei. 68. Fibers from the cuneate and gracile nucleus decussate to form internal arcuate fibers dorsal motor nucleus of vagus medial lemniscus pyramidal decussation none of the above Correct! No. The answer is C. The sensory decussation of internal arcuate fibers (answer a) from the cuneate and gracile nuclei form the medial lemniscus. Note this is completely different than the pyramidal decussation (answer D) which is a decussation of motor fibers occuring below this level in the medulla. 69. The pyramidal decussation is formed by internal arcuate fibers decussation of medial lemniscus fibers of the corticospinal tract olivocerebellar fibers none of the above Correct! No. The answer is C. The decussation of the fibers of the corticospinal tract is referred to as the pyramidal decussation because these fibers which are observed as the pyramids in a ventral view of the medulla cross to the opposite side to form the lateral corticospinal tract in the spinal cord. Note that all of these answers are crossing fibers going from one side of the medulla to the opposite side. 70. The nucleus with its tract running through the center of it is cuneate nucleus hypoglossal nucleus dorsal motor nucleus of the vagus solitary nucleus none of the above Correct! No. The answer is D. The solitary nucleus is surrounded by the solitary tract and is a key feature in its identification with the typical \"donut\" appearance. 71. The most ventral nucleus in the medulla is inferior olivary nucleus medial lemniscus medial accessory olivary nucleus arcuate nucleus none of the above Correct! No. The answer is D. The arcuate nucleus which is located at the ventral border of the pyramidal tract is the most ventral nucleus in the medulla. Note that the medial lemniscus is not a nucleus, but a tract. 72. The tract lying just ventral to the hypoglossal nucleus is rubrospinal tract medial lemniscus medial longitudinal fasciculus spinothalamic tract none of the above Correct! No. The answer is C. The medial longitudinal fasciculus is just ventral to the hypoglossal nucleus on the midline. 73. The tract lying immediately dorsal to the medial lemniscus is rubrospinal tract hypoglossal nucleus medial longitudinal fasciculus spinothalamic tract none of the above Correct! No. The answer is C. The medial longitudinal fasciculus is just dorsal to the medial lemniscus in the medial group of tracts. Note that the hypoglossal nucleus is also dorsal to the medial lemniscus but it is not a tract. 74. In the open medulla one would expect to observe all of these except nucleus ambiguus principal olivary nucleus dorsal cochlear nucleus pyramidal decussation none of the above Correct! No. The answer is D. The open medulla starts anterior to the obex, therefore this question is looking for any structure which is below the level of the obex in the closed medulla. The only structure in the closed medulla is the pyramidal decusssation. Note there are only two coronal sections that you are responsible for in the closed medulla, the pyramidal decussation level and the sensory decussation of medial lemniscus. 75. The cranial nerve rootlets which exit in the preolivary sulcus is vagus abducens hypoglossal facial none of the above Correct! No. The answer is C. The hypoglossal nerve exits from the medulla in the preolivary sulcus. 76. The cranial nerve rootlets which exit in the postolivary sulcus is Correct! No. The answer is A. The vagus nerve exits from the medulla in the post olivary sulcus. 77. The roof of the fourth ventricle in the anterior half of the pons is the superior cerebellar peduncle superior medullary velum facial colliculus hypoglossal trigone none of the above Correct! No. The answer is B. The superior medullary velum forms the roof of the fourth ventricle in the anterior half of the pons. Note that answer c and d form the floor of the fourth ventricle. 78. The cranial nerve nucleus lying immediately ventral to the facial colliculus is facial nucleus abducens nucleus hypoglossal nucleus dorsal motor nucleus of vagus none of the above Correct! No. The answer is B. The abducens nucleus lies immediately ventral to the facial colliculus. Fibers from the facial nucleus sweep over the abducens nucleus to form the genu of the facial nerve which forms part of the bump or facial colliculus. 79. The only cranial nerve to exit from the dorsal surface of the pons is facial abducens hypoglossal trochlear none of the above Correct! No. The answer is D. The trochlear nerve exits from the dorsal surface of the anterior pons. Remember the trochlear crosses to exit from the side opposite to its nucleus. 80. What nucleus is lateral to the cerebral aqueduct at upper pons level ? trochlear nucleus mesencephalic nucleus locus ceruleus both B and C none of the above Correct! No. The answer is D. Both the mesencephalic nucleus of V and the locus ceruleus lie lateral to the cerebral aqueduct in the upper pons. 81. The cranial nerve nucleus in anterior pons lying on top of MLF is trochlear nucleus mesencephalic nucleus locus ceruleus all of the above none of the above Correct! No. The answer is A. The trochlear nucleus lies on top of MLF in the anterior pons and forms the \"egg in the nest\" appearance, answer B and and C are nuclei lying lateral to the cerebral aqueduct. 82. The lateral walls of the anterior portion of the fourth ventricle are formed by the hypoglossal trigone vagal trigone medial eminence superior cerebellar peduncle none of the above Correct! No. The answer is D. The superior cerebellar peduncle forms the lateral walls of the fourth ventricle, the other answers are all part of the floor of the fourth ventricle. 83. The decussation of the superior cerebellar peduncle is found at posterior pons (coronal section) is found at anterior pons (coronal section) is a midline structure both B and C none of the above Correct! No. The answer is D. The superior cerebellar peduncle decussates in anterior pons in the midline. 84. The most ventral nucleus in the midbrain is the Edinger-Westphal nucleus oculomotor nucleus interpeduncular nucleus superior colliculus none of the above Correct! No. The answer is C. The interpeduncular nucleus is the most ventral nucleus in the midbrain, although if you chose none of the above because you thought the red nucleus was the most ventral you can also give yourself a point ! 85. The tract which surrounds the red nucleus is medial lemniscus lateral spinothalamic superior cerebellar peduncle medial longitudinal fasciculus none of the above Correct! No. The answer is C. The superior cerebellar peduncle, which is also called the dentatorubrothalamic tract surrounds, passes through and gives off synaptic connections to the red nucleus. 86. The only cranial nerve to exit from the ventral surface of the midbrain is trigeminal trochlear oculomotor optic none of the above Correct! No. The answer is C. 87. Cranial nerve III originates from trigeminal nucleus trochlear nucleus Edinger-Westphal nucleus mesencephalic nucleus none of the above Correct! No. The answer is E. The oculomotor cranial nerve originates from the oculomotor nucleus in the midbrain lying adjacent to Edinger-Westphal nucleus. 88. The fibers lying immediately dorsal, over the medial geniculate is brachium of the inferior colliculus brachium of the superior colliculus fasciculus retroflexus superior cerebellar peduncle none of the above Correct! No. The answer is B. The brachium of the superior colliculus lies immediately dorsal to and overlying the medial geniculate nucleus. Remember that the brachium of the inferior colliculus lies ventral to the medial geniculate nucleus. 89. The thalamic nucleus lying dorsal to the brachium of the superior colliculus is the medial geniculate nucleus lateral geniculate nucleus VPL thalamic nucleus pulvinar none of the above Correct! No. The answer is D. The pulvinar is a thalamic nucleus which lies just dorsal to the brachium of the superior colliculus and the medial geniculate nucleus. 90. The large gray matter structure surrounding the cerebral aqueduct is medial geniculate nucleus superior colliculus peri-aqueductal gray posterior commissure none of the above Correct! No. The answer is C. The periaqueductal gray surrounds the cerebral aqueduct and is an important area involved with pain modulation. 91. The central or middle portion of crus cerebri contains corticospinal fibers corticobulbar fibers corticopontine fibers all of the above none of the above Correct! No. The answer is D. The middle portion of crus cerebri or the cerebral peduncle contains all of these fibers. 92. In a coronal section, the cranial nerve nucleus lying ventral to the superior colliculus is trochlear oculomotor motor nucleus of V all of the above none of the above Correct! No. The answer is B. The oculomotor nucleus lies ventral to the superior colliculus, whereas the trochlear nucleus lies ventral to the inferior colliculus.