41. Site of a lesion in the basal pons involving
corticospinal and other descending motor fibers and
fibers of the abducent nerve. This lesion results in
“RAYMOND'S SYNDROME”. This lesion spares the
abducent nucleus and the nucleus and axons of the
facial nerve.
42. Site of a lesion in the caudal part of the pons
involving descending motor fibers and the axons and
nucleus of the facial nerve but sparing the nucleus
and axons of the abducent nerve. This lesion results
in the “MILLARD-GÜBLER SYNDROME”.
43. Site of a lesion causing “FOVILLE'S SYNDROME”.
Involvement of the abducent nucleus causes paralysis of
the contralateral medial rectus in addition to the
ipsilateral lateral rectus muscle. The motor nucleus and
axons of the facial nerve are also destroyed, and the lesion
extends ventrally to cause partial damage to corticospinal
and other descending motor tracts.
44.
45. 1. The following statements concern the pons:
(a) It is related superiorly to the dorsum sellae of
the sphenoid bone.
(b) It lies in the middle cranial fossa.
(c) Glial tumors of the pons are rare.
(d) The corticopontine fibers terminate in the
pontine nuclei.
(e) The pons receives its blood supply from the
internal carotid artery.
46. 2. The following statements concern the pons:
(a) The trigeminal nerve emerges on the lateral aspect
of the pons.
(b) The glossopharyngeal nerve emerges on the
anterior aspect of the brainstem in the groove
between the pons and the medulla oblongata.
(c) The basilar artery lies in a centrally placed groove
on the anterior aspect of the pons.
(d) Many nerve fibers present on the posterior aspect
of the pons converge laterally to form the middle
cerebellar peduncle.
(e) The pons forms the lower half of the floor of the
fourth ventricle.
47. 3. The following statements concern the posterior
surface of the pons:
(a) Lateral to the median sulcus is an elongated
swelling called the lateral eminence.
(b) The facial colliculus is produced by the root of the
facial nerve winding around the nucleus of the
abducent nerve.
(c) The floor of the inferior part of the sulcus limitans
is pigmented and is called the substantia ferruginea.
(d) The vestibular area lies medial to the sulcus
limitans.
(e) The cerebellum lies anterior to the pons.
48. 4. The following statements concern a transverse
section through the caudal part of the pons:
(a) The pontine nuclei lie between the transverse
pontine fibers.
(b) The vestibular nuclei lie medial to the abducent
nucleus.
(c) The trapezoid body is made up of fibers derived
from the facial nerve nuclei.
(d) The tegmentum is the part of the pons lying
anterior to the trapezoid body.
(e) The medial longitudinal fasciculus lies above the
floor of the fourth ventricle on either side of the
midline.
49. 5. The following statements concern a transverse
section through the cranial part of the pons:
(a) The motor nucleus of the trigeminal nerve lies
lateral to the main sensory nucleus in the
tegmentum.
(b) The medial lemniscus has rotated so that its long
axis lies vertically.
(c) Bundles of corticospinal fibers lie among the
transverse pontine fibers.
(d) The medial longitudinal fasciculus joins the
thalamus to the spinal nucleus of the trigeminal N.
(e) The motor root of the trigeminal nerve is much
larger than the sensory root.
