Chapter 9 : Brainstem (3) Flashcards
1. A 40-year-old female librarian is brought to emergency department. Neurological examination reveals the following: blood pressure 160/90 mm of Hg. numbness on the right side of her lower face. no weakness in upper or lower extremities deviates to right side on protrusion. uvula deviates to the left side tween the olive and the pyramid when patient says "Ah" .. The lesion causing symptoms is found in which of the fol lowing loci (A) Anterior limb of internal capsule (B) Genu of internal capsule (C) Claustrum (D) Paracentral lobule (E) Posterior limb internal capsule
I-B. A lesion of the genu of the internal capsule destroys corticobulbar fibers. The facial nucleus
receives bilateral corticobulbar input, the upper face division receives bilateral input, and the lower face division receivs only contralateral input. The hypoglossal nucleus receives only contralateral
corticobulbar input. When the tongue is protruded, it deviates to the weak side due to the unopposed activ-ity of the intact genioglossus muscle. The uvula deviates to the intact side when the patient says” AhH The muscles of the uvula and palatal arches arc innerverted by the vagal nerve (eN X).
2. The cerebral aqueduct is found in which part of the brain? . (A) Telencephalon (B) Diencephalon (C) Mesencephalon (D) Metencephalon (E) Myelencephalon
2-C. The cerebral aqueduct is found in the mesencephalon; it connects the third ventricle to the fourth ventricle
- All of the following statement concerning the trapezoid body are correct EXCEPT
(A) it is found in the ventral pontine tegmentum
(B) it contains the medial longitudinal fasci¬¬culus (MLF)
(C) it contnins the medial lemniscus •
(D) it contains aberrant corticobulbar fibers
(E) it contains auditory fibers
3-B. The trapezoid body contains auditory fibers from the cochlear and superior olivary nuclei,
the medial lemniscus, and corticobulbar fibers. Exiting intra-axial abducent fibers pass through
the trapezoid body. The medial longitudinal fasciculus (MLF) lies dorsal to this structure.
- All of the following statements concerning the medulla oblongata are correct EXCEPT
(A) itextends from the pyramidal decussation - pontine sulcus –
(B) it contains the facial nucleus
(C) itcontains the medial and inferior vestibular nuclei
(D) it contains the inferior olivary nucleus
(E) it contains the nucleus ambiguus
4-B. On its ventral aspect, the medulla extends from the pyramidal decussation to the inferior
pontine sulcus (pontobulbar sulcus); on its dorsal aspect, it extends from the pyramidal decussation
to the striae medullares of the rhomboid fossa. The medial and inferior vestibular nuclei are found in the medulla and extend into the caudal pontine tegmentum. The inferior olivary nucleus, a cerebellar relay nucleus, is the most prominent nucleus of the medulla. The nucleus ambiguus
is found in the medulla; it gives rise to special visceral efferent.(SVE) fibers of eN IX, eN
x, and eN XL The facial nucleus is found in the caudal pontine tegmentum.
- All of the following statements concerning thethe hypoglossal nucleus are correct EXCEPT
(A).it gives rise to special visceral efferent (SVE) fibers
(B) It has axon that exit the medulla be¬tween the olive and the pyramid
(C) it lies dorsal to the medial longitudinal fasciculus (MLF)
(D) it innervates the intrinsic musculature of the tongue
(E) its intra•axial root fibers lie adjacent to the medial lemniscus
5-A. The hypoglossal nucleus of eN XII gives rise.to general somatic efferent (GSE) fibers. The
hypoglossal nucleus lies dorsal to the medial longitudinal fasciculus (MLF), glvesrls;to fibers
that exit the medulla in the preolivary sulcus, and innervates the intrinsic and extrinsic muscles of the tongue (except the palatoglossus muscle, which is innervated by eN X). Intra-axial root fibers lie between the medial lemniscus and the inferior olivary nucleus.
- All of the following statements concerning the motor nucleus of the trigeminal nerve are correct EXCEPT
(A) it plays a role in the corneal reflex
(B) it lies medial to the principal sensory nucleus ofCNV •
C) it is located in the rostral pontine tegmen¬tum
(D) it receives bilateral input from corticobul¬ bar fibers
(E) it gives rise to special visceral efferent (SVE) fibers
6-A. The motor nucleus of the trigeminal nerve (eN V) is a component of the special visceral efferent
(SVE) cell column, lies medial to the principal sensory nucleus of CN V, is found in the rostral
pontine tegmentum, and receives bilateral cortico bulbar input. The afferent limb of the corneal reflex is the ophthalmic nervI! (eN V-I); the efferent limb is the facial nerve (eN Vll), which innervates the orbicularis oculi muscle.
- All of the following statements concerning’ the trochlear nerve are correct EXCEPT
(A) it has its nucleus in the midbrain tegmentum
(B) it exits the brainstem caudal to the infe rior colliculus
(C) it decussates in the superior medullary velum
(D) it innervates a muscle that depresses the globe
(E) it innervates a muscle that extorts theglobeto the inferior
7-E. The trochlear nerve (CN IV) has its nucleus in the midbrain tegmentum at the level of the inferior colliculus. It decussates in the superior medullary velum and exits the brainstem lateral to the frenulum of the superior medullary velum. It is the only cranial nerve to exit the brainstem from the dorsal surface. It innervates the superior oblique muscle, which depresses, intorts and abducts. the eyeball.
- All of the following statements concerning the oculomotor nuclear complex are correct EXCEPT
(A) stimulation of its parasympathetic component results in mydriasis
(B) damage to its general somatic efferent (GSE) fibers results in severe ptosis
(C) it is found in the midbrain at the level of the superior colliculus
(D) its preganglionic parasympathetic fibers ¬synapse in the ciliary ganglion
(E) its exiting GSE fibers pass through the crus cerebri
8-A. Stimulation of the parasympathetic component results in miosis (sphincter pupillae muscle). Preganglionic parasympathetic fibers synapse in the ciliary ganglion. The oculomotor nuclear complex is found in the midbrain at the level of the red nucleus and the superior colliculus.
Exiting oculomotor fibers pass through the crus cerebri. Transection of these fibers results in severe
ptosis, a dilated pupil paralysis of the medial. superior, and inferior recti muscles and paralysis
of the inferior oblique and the levator palpebrae muscles. The paralytic eye “looks down and
out.”
The response options for items 9-16 are thesame. You will be required to select one answer for each item in the set.
(A) Midbrain, at level of superior colliculus
(B) Midbrain, at level of inferior colliculus
(C) Tegmentum of pons
(D) Base of pons
(E) Lateral medulla
(F) Medial medulla
Match the following structures with the appropriate brainstem division
- Decussation of the superior cerebellar peduncle
9-B. The decussation of the superior ccrchellnr peduncle is diagnostic of midbrain division at the level of the inferior colliculus
The response options for items 9-16 are thesame. You will be required to select one answer for each item in the set.
(A) Midbrain, at level of superior colliculus
(B) Midbrain, at level of inferior colliculus
(C) Tegmentum of pons
(D) Base of pons
(E) Lateral medulla
(F) Medial medulla
Match the following structures with the appropriate brainstem division
- Inferior olivary nucleus
10-E. The inferior olivary nucleus. a cerebellar relay nucleus. is the most prominent nucleus in the lateral medulla.
The response options for items 9-16 are thesame. You will be required to select one answer for each item in the set.
(A) Midbrain, at level of superior colliculus
(B) Midbrain, at level of inferior colliculus
(C) Tegmentum of pons
(D) Base of pons
(E) Lateral medulla
(F) Medial medulla
Match the following structures with the appropriate brainstem division
- Nucleus ambiguus
ll-E. The nucleus ambiguus is found in the lateral medulla; it gives rise to the special visceral efferent (SVE) components of cranial nerves IX. X. and XI.
The response options for items 9-16 are thesame. You will be required to select one answer for each item in the set.
(A) Midbrain, at level of superior colliculus
(B) Midbrain, at level of inferior colliculus
(C) Tegmentum of pons
(D) Base of pons
(E) Lateral medulla
(F) Medial medulla
Match the following structures with the appropriate brainstem division
- Abducent nucleus
12-C. The abducent nucleus (CN VI) is located in the dorsomedial tegmentum of the pons. All
brainstem cranial nerve nuclei are found in the tegmentum
The response options for items 9-16 are thesame. You will be required to select one answer for each item in the set.
(A) Midbrain, at level of superior colliculus
(B) Midbrain, at level of inferior colliculus
(C) Tegmentum of pons
(D) Base of pons
(E) Lateral medulla
(F) Medial medulla
Match the following structures with the appropriate brainstem division
- Facial nucleus
l3-c. The facial nucleus (CN VII) is located in the lateral tegmentum of the pons.
The response options for items 9-16 are thesame. You will be required to select one answer for each item in the set.
(A) Midbrain, at level of superior colliculus
(B) Midbrain, at level of inferior colliculus
(C) Tegmentum of pons
(D) Base of pons
(E) Lateral medulla
(F) Medial medulla
Match the following structures with the appropriate brainstem division
- Oculomotor nucleus
I4-A. The oculomotor nucleus (CN III) lies in the dorsomedial tegmentum of the midbrain atthe level of the superior colliculus; it lies medial to the medial longitudinal fasciculus
The response options for items 9-16 are thesame. You will be required to select one answer for each item in the set.
(A) Midbrain, at level of superior colliculus
(B) Midbrain, at level of inferior colliculus
(C) Tegmentum of pons
(D) Base of pons
(E) Lateral medulla
(F) Medial medulla
Match the following structures with the appropriate brainstem division
- Red nucleus
I5-A. The red nucleus is diagnostic of midbrain division at the level of the superior colliculus;’ it lies between the oculomotor nucleus (eN lIT) and the substantia nigra.
