Brainstem: Medulla Oblongata 125
Multiple Choice Questions
1. The following statements about brainstem are true except
a. It consist of pons, medulla and cerebellum
b. It is continuous above with the thalamus, hypothala-
mus and cerebral hemispheres
c. It is continuous below with the spinal cord
d. It lies in posterior cranial fossa
(Refer to page 11)
2. Which of the following statements about attachment of
cranial nerves is false?
a. Brainstem gives attachment to all the cranial nerves
b. The nuclei of cranial nerves III to XII are situated
deep in the brainstem
c. Cranial nerves III and IV are attached to midbrain
d. Cranial nerve V is attached to pons
e. Cranial nerves IX to XII are attached to medulla
(Refer to page 112)
3. Which of the following statements about the ventral
aspect of medulla is false?
a. On either side of the anteromedian fissure, there is the
presence of a pyramid
b. Olive is present lateral to the anterolateral sulcus
c. Posterolateral sulcus gives attachment to cranial nerve
XII
d. Ventral aspect of medulla is related to basisphenoid
(clivus)
e. Anterolateral sulcus is present between the olive and
pyramid
(Refer to page 116)
4. Which of the following statements about the posterior
surface of the lower part of medulla is true?
a. This surface lies between the posteromedian sulcus
and posterolateral sulcus
b. This surface is an upward continuation of fasciculi
gracilis and cuneatus
c Fasciculi gracilis and cuneatus are continuous above
as gracile and cuneate tubercles
d. Lateral to fasciculus cuneatus, a swelling is seen that
is known as tuberculum cinereum
e. All of the above
(Refer to page 116)
5. Which of the following statements about the transverse
section of medulla at the level of sensory decussation is
false?
a. This level is cranial to pyramidal decussation
b. Nuclei gracilis and cuneatus are situated on the poste-
rior aspect of the section
c. Nucleus of the spinal tract of the trigeminal nerve is
situated ventrolateral to nucleus cuneatus
d. Nucleus ambiguus is situated in the area of reticular
formation
e. None of the above
(Refer to pages 120 and 121)
6. Which of the following facts about the medial longitudi-
nal bundle is false?
a. In the medulla, it is present posterior to media lemnis-
cus
b. It is present anterior to hypoglossal nucleus
c. It is present throughout the brainstem in the same
paramedian position
d. It consists of ascending and descending fibres con-
necting various cranial nerve nuclei (III, IV, VI and
VIII) with each other
e. None of the above
(Refer to page 121)
7. Medial medullary syndrome is caused due to occlusion
of
a. Anterior spinal artery
b. Posterior inferior cerebellar artery
c. Pontine artery
d. Vertebral artery
(Refer to page 123)
8. Lateral medullary syndrome is caused due to occlusion
of
a. Vertebral artery
b. Anterior spinal artery
c. Posterior inferior cerebellar artery
d. Anterior inferior cerebellar artery
(Refer to page 124)
spinocerebellar tracts are situated in the ventrolateral area
of the medulla near the surface (
Fig. 10.10
).
The section passing through the open part of medulla
•
(lower part of the fourth ventricle) shows the most strik-
ing change; that is, instead of the central canal, the fourth
ventricle is seen.
Due to the opening of the central canal position of the
•
hypoglossal nucleus, vagal nucleus and nucleus solitarius
have changed (compare
Fig. 10.10
with
Fig. 10.11
). Note
the location of vestibular and cochlear nuclei in the lat-
eral part of the section. The nucleus ambiguus and spinal
nucleus of the trigeminal have maintained the same posi-
tion as in the lower section.
The olivary nuclear complex (inferior, medial and dorsal
•
olivary nuclei) is located in the ventrolateral area of the
section (
Fig. 10.11
).
The arrangement of white matter is almost the same as
•
at a lower level. The appearance of the inferior cerebellar
peduncle is a new feature at this level.
Lesions of medulla may result due to a variety of causes:
•
Injury, congenital anomaly and vascular lesions.
Bulbar palsy is due to bilateral lesion of the lower brain-
•
stem affecting the functions of cranial nerves VII to XII.
This is a lower motor neuron type of paralysis affecting
the muscles of face, pharynx, larynx, palate and tongue.
Pseudo-bulbar palsy results due to bilateral lesion of
•
the corticobulbar fibres. It is of the upper motor neuron
type.
Ch_10_NA.indd 125
8/28/2012 1:00:41 PM
