Block 5 Neuro Atlas Ch 7 W Expl
(145).webp "Block 5 Neuro Atlas Ch 7 W Expl - Quiz")
Questions and Answers
- 1.
The MRI of a 66-year-old man shows a tumor 2.0 cm in diameter located in the lateral wall of the atrium of the lateral ven-tricle.Which of the following structures does this lesion mostlikely damage?
- A.
Corticonuclear fibers
- B.
Corticospinal fibers
- C.
Optic radiations
- D.
Pulvinar nucleus
- E.
Splenium,corpus callosum
Correct Answer
C. Optic radiationsExplanation
The optic radiations are located in the lateral wall ofthe atrium of the lateral ventricle,represent projections from thelateral geniculate nucleus to the calcarine cortex,pass through the retrolenticular limb of the internal capsule,and are separated from the ventricular space by a thin layer of fibers called thetapetum.
The pulvinar and splenium are located rostromedial and medial, respectively, to the atrium.Corticonuclear and corticospinal fibers are found in the genu,and the posterior limb ofthe internal capsule within the hemisphere.(p.164,166)Rate this question:
-
- 2.
Which of the following structures is clearly seen in coronal and axial brain slices, and in many MRIs, in sagittal planes extending from the midline laterally through the basal nuclei?
- A.
Anterior commissure
- B.
Column of the fornix
- C.
Genu of the internal capsule
- D.
Optic chiasm
- E.
Posterior commissure
Correct Answer
A. Anterior commissureExplanation
The anterior commissure is a mediolaterally oriented bundle of fibers that crosses the midline and extends laterally,immediately inferior to the basal nuclei.In sagittal section,or in a sagittal MRI, this bundle can be followed into planes of the hemisphere that include the most lateral portions of the thalamus and lenticular nucleus. The column of the fornix and optic chiasm are located immediately adjacent to the midline.The posterior commissure is located at the caudal aspect of the third ventricle and immediately superior to the opening of the cerebral aqueduct.The genu of the internal capsule is medial to the lenticular nucleus and rostrolateral to the anterior nucleus of the thalamus. (p.165,167,168,170)Rate this question:
-
- 3.
The MRI of a 59-year-old woman with movement and personality disorders and with cognitive dysfunction shows a large anterior horn of the lateral ventricle. The attending physician suspects that her disease has resulted in loss of brain tissue inthe lateral wall of the anterior horn. A loss of which of the following structures would result in this portion of the ventricular system being enlarged?
- A.
Body of the caudate nucleus
- B.
Head of the caudate nucleus
- C.
Lenticular nucleus
- D.
Pulvinar nucleus (i)
- E.
Septum pellucidum and fornix
Correct Answer
B. Head of the caudate nucleusExplanation
The head of the caudate nucleus forms a prominent bulge in the lateral wall of the anterior horn of the lateral ventricle. In Huntington disease, this elevation disappears, and the wall of the ventricle may become concave laterally; the result being an enlarged anterior horn (hydrocephalus
ex vacuo). The body of the caudate is located in the lateral wall of the body ofthe lateral ventricle. The lenticular nucleus lies within the hemisphere and does not border on any ventricular space. The septum and fornix are located in the medial wall of the ventricle, and the pulvinar borders on the superior cistern. (p.164,166,169)Rate this question:
-
- 4.
The axial MRI of a 54-year-old man shows an arteriovenous malformation located between the thalamus and lenticular nucleus. Which of the following structures is probably most affected by this malformation?
- A.
Anterior commissure
- B.
Anterior limb of the internal capsule
- C.
Extreme capsule
- D.
Retrolenticular limb of the internal capsule
- E.
Posterior limb of the internal capsule
Correct Answer
E. Posterior limb of the internal capsuleExplanation
The posterior limb of the internal capsule is located between the lenticular nucleus, which is lateral, and the thalamus,which is medial. This large fiber bundle contains thalamocortical projections related to motor and sensory function and descending corticospinal fibers.The anterior limb of the inter-nal capsule is located between the head of the caudate and the lenticular nucleus, and the retrolenticular limb is found caudal to the lenticular nucleus. The anterior commissure is in the ros-troventral portion of the hemisphere, and the extreme capsuleis immediately internal to the insular cortex. (p.166,168)Rate this question:
-
- 5.
In a sagittal MRI, and in a sagittal brain slice, both taken just off the midline (2–4 mm), which of the following structures would be clearly evident immediately caudal to the anterior commissure?
- A.
Column of the fornix
- B.
Lamina terminalis
- C.
Mammillothalamic tract
- D.
Optic chiasm
- E.
Precommissural fornix
Correct Answer
A. Column of the fornixExplanation
The column of the fornix, commonly called the postcommissural fornix, lies caudal to,and against, the anterior commissure as it arches around the interventricular foramen and anterior tubercle of the thalamus.
The precommissural fornix is a diffuse bundle of fibers rostral to the anteriorcommissure, and the mammillothalamic tract is located between the mammillary body and anterior nucleus of thethalamus.
The lamina terminalis and optic chiasm are inferiorto the anterior commissure.(p.165,166)Rate this question:
-
- 6.
The coronal MRI of a 2-year-old child shows a 2.0-cm diameter tumor in the rostral tip of the temporal (inferior) horn of the lateral ventricle. It is possibly arising from the choroid plexus in this area of the ventricle. In addition to the hippocampus, this tumor is most likely impinging on which of the following structures?
- A.
Amygdaloid nucleus
- B.
Body of the caudate nucleus
- C.
Hypothalamus
- D.
Optic radiations
- E.
Putamen
Correct Answer
A. Amygdaloid nucleusExplanation
The amygdaloid nucleus is in the rostral wall of thetemporal horn of the lateral ventricle.In this position theamygdala is separated from the rostral tip of the hippocampus(the hippocampus occupies the medial and inferior wall of thetemporal horn) by a narrow space of the ventricle.The opticradiations are in the lateral wall of the temporal horn,but arequite caudal to its rostral tip.The other choices do not havedirect structural relationship to the rostral portions of the tem-poral horn.(p.172–173)Rate this question:
-
- 7.
Which of the following structures is located immediately internal to the crus cerebri and appears as a dark shade of grey(hypointense) in a sagittal T1-weighted MRI?
- A.
Brachium of the inferior colliculus
- B.
Periaqueductal grey
- C.
Pretectal area
- D.
Red nucleus
- E.
Substantia nigra
Correct Answer
E. Substantia nigraExplanation
The substantia nigra is located internal to the cruscerebri and,in T1-weighted MRI,appears a darker shade of grey(hypointense) than does the crus.The red nucleus and the peri-aqueductal grey are located in the midbrain,but do not borderon the crus cerebri.The brachium of the inferior colliculus isfound on the lateral surface of the midbrain,and the pretectalarea is adjacent to the cerebral aqueduct at the midbrain–dien-cephalic junction.(p.167,170–172)Rate this question:
-
- 8.
An 81-year-old man is brought to the emergency department following a fall while walking in the park.The examination reveals mild confusion and memory loss, but no obvious motoror sensory deficits. MRI shows an old infarct in the territory of the thalamus served by the thalamoperforating artery. Which of the following nuclei is most likely involved in this lesion?
- A.
Centromedian
- B.
Medial geniculate
- C.
Ventral anterior
- D.
Ventral posterolateral
- E.
Ventral posteromedial
Correct Answer
C. Ventral anteriorExplanation
The ventral anterior nucleus is located in the rostralportions of the thalamus,is in the territory of the thalamoper-forating artery,and projects to large regions of the frontal lobe.An occlusion of the vessels serving this portion of the thalamusmay result in a decreased level of alertness.The other choicesare in caudal regions of the thalamus,are not in the territoryserved by the thalamoperforating artery,and,with the excep-tion of the centromedian nucleus,do not relate to the cortex ofthe frontal lobe.(p.167,169)Rate this question:
-
- 9.
Which of the following nuclei is located within the internal medullary lamina and may be visible in an axial MRI in eitherT1- or T2-weighted images?
- A.
Centromedian
- B.
Dorsomedial
- C.
Pulvinar
- D.
Ventral anterior
- E.
Ventral lateral
Correct Answer
A. CentromedianExplanation
The centromedian nucleus is found within the inter-nal medullary lamina in a position just rostral to the pulvinar.The ventral anterior and ventral lateral nuclei are lateral to theinternal medullary lamina,the dorsomedial nucleus is medialto this lamina,and the pulvinar is the large nucleus formingthe caudal part of the dorsal thalamus.(p.164,166)Rate this question:
-
- 10.
The sagittal MRI of a 23-year-old woman shows a mass in the right interventricular foramen (possibly a colloid cyst); the right lateral ventricle is enlarged. Based on its location, this mass is most likely impinging on which of the following structures?
- A.
Anterior nucleus of thalamus
- B.
Posterior limb of internal capsule
- C.
Habenular nucleus
- D.
Head of caudate nucleus
- E.
Lamina terminalis
Correct Answer
E. Lamina terminalisExplanation
The interventricular foramen is the space formed between the column of the fornix (located somewhat rostrome-dially) and the anterior nucleus of the thalamus (located some-what caudolaterally).The anterior nucleus is located internal to the anterior tubercle of the thalamus.The head of the caudate is found in the lateral wall of the anterior horn of the lateral ventricle,and the posterior limb is located in the hemi-sphere between the thalamus and lenticular nucleus.The lamina terminalis extends from the anterior commissure inferiority to the upper edge of the optic chiasm.The habenula is a small elevation in the caudal and medial wall of the third ven-tricle.(p.164,166)Rate this question:
-
- 11.
The sagittal MRI of a 42-year-old woman taken adjacent to the midline shows a round structure immediately rostral to the interpeduncular fossa on the inferior surface of the hemisphere. Which of the following most likely represents this elevation?
- A.
Anterior commissure
- B.
Basilar pons
- C.
Lamina terminalis
- D.
Mammillary body
- E.
Optic chiasm
Correct Answer
D. Mammillary bodyExplanation
The mammillary body forms an obvious elevation onthe inferior aspect of the hemisphere rostral to the interpeduncular fossa/cistern; this small bulge is clearly evident in MRI.Theoptic chiasm and the basilar pons are both on the inferior aspect of the brain at the midline. The former is rostral to the infundibulum (and the mammillary body) and the latter is caudal to the interpeduncular fossa.The lamina terminalis forms the rostral end of the third ventricle and the anterior commissure is adjacent to the column of the fornix.(p.31,165,172)Rate this question:
-
- 12.
Which of the following structures is located immediately inferior to the pulvinar and,in the sagittal plane (MRI or brain sec-tion), forms a distinct elevation immediately adjacent to the crus cerebri?
- A.
Mammillary nuclei
- B.
Medial geniculate nucleus
- C.
Optic tract
- D.
Subthalamic nucleus
- E.
Uncus
Correct Answer
B. Medial geniculate nucleusExplanation
The medial and lateral geniculate nuclei are located inferior to the pulvinar, and form elevations on the surface of the dorsal thalamus; the medial geniculate is adjacent to thelateral edge of the crus cerebri. The subthalamic nucleus islocated internally, the mammillary nuclei (medial and lateral)are on the inferior aspect of the thalamus, and the uncus is on the medial portion on the temporal pole.The optic tract lies onthe surface of the crus cerebri, but it does not form a distinct elevation on the brain surface inferior to the pulvinar; rather, it has a structural relationship to the lateral geniculate nucleus.(p.168,170,173)Rate this question:
-
Quiz Review Timeline +
Our quizzes are rigorously reviewed, monitored and continuously updated by our expert board to maintain accuracy, relevance, and timeliness.
-
Current Version
-
Jan 30, 2024Quiz Edited by
ProProfs Editorial Team -
Jan 15, 2012Quiz Created by
Chachelly
Back to top