Chapter I : Gross Anatomy of the Brain (4)

Question 1

1. Which one of the following structures is found in the diencephalon?

(A) thalamus
(B) cerebral hemispheres
(C) globus pallidus
(D) caudate nucleus
(E) internal capsule

Answer 1

1–A. The thalamus, along with the epithalamus, hypothalamus and the subthalamus comprise the diencephalon. The diencephalon lies deep to the prosencephalon and rostral to the midbrain.

Question 2

2. The hippocampal formation is part of the

(A) frontal lobe
(B) parietal lobe
(C) insular lobe
(D) limbic lobe
(E) occipital lobe

Answer 2

2–D. The hippocampus is part of the limbic system and plays a role in memory. The name derives from Greek and is based on its jelly-roll shape, which resembles a sea horse. The hippocampus is one of the first regions damaged in Alzheimer’s disease.

Question 3

3. Which one of the cranial nerves exits the brainstem from the dorsal aspect?

(A) CN I
(B) CN II
(C) CN III
(D) CN IV
(E) CN VI

Answer 3

3–D. The trochlear nerve (CN IV) is the only cranial nerve to exit the brainstem from the dorsal aspect.

Question 4

4. Heschl’s gyrus receives input from which of the following neural structures?
   (A) angular gyrus
   (B) medial geniculate nucleus
   (C) primary auditory cortex
   (D) sensory strip
   (E) supramarginal gyrus

Answer 4

4–B. Primary auditory cortex (41, 42) is found in the Heschl gyrus, and receives input from the
medial geniculate nucleus. The postcentral gyrus is the “sensory strip,” the somatosensory cortex
(3,1,2). The parietal lobe includes the angular gyrus, which receives visual impulses (39) and
supramarginal gyrus, which interrelates somatosensory, auditory, and visual input (40).
Destruction of the angular and supramarginal gyri on the dominant (usually left) side gives rise
to the Gerstmann syndrome, whose symptoms include agraphia, acalculia, finger agnosia and
left-right disorientation.

Question 5

5. Lies within the cavernous sinus

Answer 5

5–D. The carotid artery lies within the cavernous sinus, in company with CN III, CN IV, CN V-1,
CN V-2, and CN VI; aneurysms of the internal carotid artery and tumors of the cavernous sinus
may cause cranial nerve palsies.

Question 6

6. Lies within the sella turcica

Answer 6

6–E. The hypophysis (pituitary gland) lies within the hypophyseal fossa of the sella turcica; common
tumors in this region are pituitary adenomas, craniopharyngiomas, and meningiomas.

Question 7

7. Is part of the striatum

Answer 7

7–B. The caudate nucleus and putamen are parts of the striatum. In Huntington disease there is
a loss of neurons in the caudate nucleus; in Parkinson disease there is a loss of pigmented neurons
in the substantia nigra.

Question 8

8. Is part of the limbic lobe

Answer 8

8–A. The cingulate gyrus is part of the limbic lobe; lesions may result in akinesia, mutism, apathy,
and indifference to pain.

Question 9

9. Lies within a cistern

Answer 9

9–C. The optic chiasm lies within the chiasmatic cistern.

Question 10

10. Has reciprocal connections between the hippocampal formation and the septal nuclei

Answer 10

10–E. The fornix contains fibers from the hippocampal formation and from the septal nuclei. The
fornix projects massively to the mamillary nuclei of the hypothalamus.

Question 11

11. Largest nucleus of the diencephalon

Answer 11

11–C. The pulvinar nucleus is the largest nucleus of the thalamus. It has reciprocal connections
with the association cortex of the occipital, parietal, and posterior lobes and is concerned with
the integration of visual, auditory, and somesthetic input.

Question 12

12. Internal capsule

Answer 12

12–D. The posterior limb of the internal capsule lies between the lentiform nucleus and the thalamus.
It contains the corticospinal tract and is perfused by the lateral striate arteries (branches of
MCA) and the anterior choroidal artery.

Question 13

13. Cingulate gyrus

Answer 13

13–A. The cingulate gyrus contains the cingulum, a fiber bundle that interconnects the hippocampal
formation with the septal nucleus. Bilateral destruction of the cingulate gyrus causes
loss of inhibition as well as dulling of the emotions. Memory is unaffected. Lesions of the anterior
cingulate gyri cause placidity; cingulectomy is used to treat severe anxiety and depression.

Question 14

14. Caudate nucleus

Answer 14

14–B. The caudate nucleus and the putamen comprise the striatum, a basal ganglion. In
Huntington disease, massive loss of neurons in the head of the caudate nucleus results in hydrocephalus
ex vacuo. The globus pallidus and subthalamic nucleus are also basal ganglia.