11 Brainstem and Corticobulbar Pathways - B

Question 1

*What CN is only associated with the medulla

Answer 1

CN 9, 10, 12

Question 2

*What is the pathway of the accessory n

Answer 2

Located in spinal cord from C1-6 —> foramen magnum —> out jugular foramen

Question 3

*Lesions of the CN 11 root cause what

Answer 3

-drooping of the shoulder -scapular winging -turning of head to contralateral side

Question 4

*Axons of MN pass anteriorly in medulla along lateral aspects of medial lemniscus and the pyramid as what CN

Answer 4

CN 12 via the hypoglossal canal

Question 5

*The hypoglossal n distributes to what mm

Answer 5

Intrinsic tongue mm, hyoglossus, palatoglossus, genioglossus

Question 6

*The dorsal motor nucleus of vagus is primarily innervation to what

Answer 6

-parasympathetic preganglionic to visceral structures of trachea, bronchi, heart, and GI up to splenic flexure

Question 7

*The nucleus ambiguus innervate what

Answer 7

Pharyngeal and laryngeal targets Skel M in upper half of esophagus

Question 8

Somatic afferent (pain & thermal) from a small area of ear, part of the external auditory meatus, dural of the posterior cranial fossa come from what CN

Answer 8

Vagus

Question 9

Central processes of the vagus (visceral afferent and taste) enter via

Answer 9

Solitary tract and terminate in teh surrounding caudal solitary nucleus

Question 10

A lesion of the root of the vagus can cause what symptoms

Answer 10

-dysphagia -dysarthria -very few taste defects (laryngeal, epiglottis, posterior most tongue)

Question 11

*Glossopharyngeal n motor fibers originate from

Answer 11

Inferior salivatory nucleus and nucleus ambiguus

Question 12

*What does the CN 9 part of nucleus ambiguus o

Answer 12

SE (to stylopharyngeus m) Plays a minor role in the efferent limb of gag reflex

Question 13

The glossopharyngeal n lesions causes what

Answer 13

-diminished taste on posterior tongue -loss of stylopharngeus which participates in gag refelx

Question 14

Glossopharyngeal neuralgia is

Answer 14

Intense idiopathic pain along the sensory distribution of the n

Question 15

*What are the CN at the pon-medulla junction

Answer 15

CN 6, 7, 8

Question 16

What exits along the caudal edge of the pons

Answer 16

CN 6, 7, 8

Question 17

The facial motor nucleus follows what path

Answer 17

Arch around the abducens nucleus to exit brainstem

Question 18

*SE fibers from the facial motor nucleus are joined by axons from

Answer 18

Superior salivatory nucleus (VE pre-gang para)

Question 19

*The facial n emerges from the brainstem as what

Answer 19

Facial n fibers and intermediate n fibers

Question 20

What does the facial n provide sensory innervation for

Answer 20

-taste fibers for anterior 2/3 of tongue -cutaneous sensory (SA) fibers from external ear (posterior 1/2 of pinna) and external auditory canal

Question 21

Taste fibers enter _______ and terminate rostrally in _____________

Answer 21

Solitary tract; gustatory nucleus of solitary nucleus (the central receiving area for all taste sensation)

Question 22

Facial n sensory fibers to the ear and external auditory canal reach cell bodies in the _________ and their central processes enter _____________ and terminate in ____________

Answer 22

Geniculate ganglion; spinal trigeminal tract; spinal trigeminal nucleus

Question 23

*The nucleus of the abducens (CN 6) is surrounded by

Answer 23

Internal genu of facial n

Question 24

SE motor neurons of CN 6 innervate _________________ while interneurons send axons to ___________________

Answer 24

Ipsilateral lateral rectus m; contralateral axons to medial longitudinal fasiculus (target contralateral occluomotor nucleus)

Question 25

Injury of CN6 in the pons causes

Answer 25

Paralysis of ipsilateral LR muscle \*opposite eye adducts b/c interneurons are intact

Question 26

A lesion of the abducens nucleus causes

Answer 26

Paralysis of of LR ipsilaterally and failure of contralateral medial rectus m to contract toward the side of the lesion

Question 27

\*\*\*Damage to the medial longitudinal fasiculus causes

Answer 27

Inability to adduct the contralateral eye on attempted gaze contralaterally \*\*\*need to fact check this

Question 28

CN of the midbrain include

Answer 28

CN 3, 4

Question 29

\*Where are CN 3,4 in relation to the periaqueductal gray

Answer 29

Ventral

Question 30

CN 3, 4 are exclusively

Answer 30

Motor

Question 31

What CN do not receive corticonuclear fibers

Answer 31

CN 3, 4

Question 32

\*The trochlear n is the only motor cranial n to do what

Answer 32

Decussate before exiting

Question 33

\*The trochlear nucleus is located where in regards to MLF

Answer 33

Posteriorly but adjacent to

Question 34

Lesion of the nerve root of CN 4 cause

Answer 34

Paralysis of superior oblique m on that side

Question 35

\*The occulomotor nucleus is located where

Answer 35

Within the ventral portion of the PAG and present in about the rostral half of the midbrain

Question 36

Innervation of the occluomotor n is ipsilateral except for

Answer 36

Superior rectus m

Question 37

The Edinger Westphal nucleus sends

Answer 37

Preganglionic gibers to the ciliary ganglion

Question 38

\*The ciliary ganglion gives off short ciliary nn which innervate what

Answer 38

Sphincter pupillae and ciliary mm

Question 39

\*Lesions involving occulomotor nucleus nerve generally have same result

Answer 39

-down and out gaze -diplopia -myadriasis -no accommodation

Question 40

The corticonuclear system consists of UMN that influence

Answer 40

Motor nuclei of CN 5, 7, 12 Nucleus ambiguus (CN 9, 10) Accessory nucleus (CN 11)

Question 41

The trigeminal nuclei distributes fibers in what way

Answer 41

Equal numbers b/l

Question 42

\*Muscles in upper 1/2 of face are controlled

Answer 42

Both hemispheres

Question 43

\*Muscles in the lower half of the face are primarily controlled by

Answer 43

Contralateral hemisphere

Question 44

\*A lesion rostral to facial motor nucleus results in

Answer 44

Drooping of mm at corners of mouth and lower face contralaterally (central facial paralysis)

Question 45

\*A lesion of the root of the facial n will result in

Answer 45

Flaccid paralysis of upper and lower portions of face on ipsilateral side (Bell palsy)

Question 46

\*The soft palate/uvula is mainly innervated by

Answer 46

Contralateral MN

Question 47

\*Lesion of the corticonuclear fibers on the right would cause

Answer 47

-weakness of palate arch mm on the left -slight drooping of palatal arch on left -deviation of uvula to right on phonation (left at rest)

Question 48

Genioglossus is innervated how

Answer 48

Contralaterally from CN 12

Question 49

Lesions of CN 12 deviate

Answer 49

Towards dysfunction

Question 50

A left protruding tongue could be caused by

Answer 50

Right corticonuclear fibers (UMN) lesion OR left hypoglossal n (LMN)