11 Brainstem and Corticobulbar Pathways - B Flashcards Preview

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Flashcards in 11 Brainstem and Corticobulbar Pathways - B Deck (50)
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1
Q

*What CN is only associated with the medulla

A

CN 9, 10, 12

2
Q

*What is the pathway of the accessory n

A

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

3
Q

*Lesions of the CN 11 root cause what

A

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

4
Q

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

A

CN 12 via the hypoglossal canal

5
Q

*The hypoglossal n distributes to what mm

A

Intrinsic tongue mm, hyoglossus, palatoglossus, genioglossus

6
Q

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

A

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

7
Q

*The nucleus ambiguus innervate what

A

Pharyngeal and laryngeal targets Skel M in upper half of esophagus

8
Q

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

A

Vagus

9
Q

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

A

Solitary tract and terminate in teh surrounding caudal solitary nucleus

10
Q

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

A

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

11
Q

*Glossopharyngeal n motor fibers originate from

A

Inferior salivatory nucleus and nucleus ambiguus

12
Q

*What does the CN 9 part of nucleus ambiguus o

A

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

13
Q

The glossopharyngeal n lesions causes what

A

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

14
Q

Glossopharyngeal neuralgia is

A

Intense idiopathic pain along the sensory distribution of the n

15
Q

*What are the CN at the pon-medulla junction

A

CN 6, 7, 8

16
Q

What exits along the caudal edge of the pons

A

CN 6, 7, 8

17
Q

The facial motor nucleus follows what path

A

Arch around the abducens nucleus to exit brainstem

18
Q

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

A

Superior salivatory nucleus (VE pre-gang para)

19
Q

*The facial n emerges from the brainstem as what

A

Facial n fibers and intermediate n fibers

20
Q

What does the facial n provide sensory innervation for

A

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

21
Q

Taste fibers enter _______ and terminate rostrally in _____________

A

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

22
Q

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

A

Geniculate ganglion; spinal trigeminal tract; spinal trigeminal nucleus

23
Q

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

A

Internal genu of facial n

24
Q

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

A

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

25
Q

Injury of CN6 in the pons causes

A

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

26
Q

A lesion of the abducens nucleus causes

A

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

27
Q

***Damage to the medial longitudinal fasiculus causes

A

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

28
Q

CN of the midbrain include

A

CN 3, 4

29
Q

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

A

Ventral

30
Q

CN 3, 4 are exclusively

A

Motor

31
Q

What CN do not receive corticonuclear fibers

A

CN 3, 4

32
Q

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

A

Decussate before exiting

33
Q

*The trochlear nucleus is located where in regards to MLF

A

Posteriorly but adjacent to

34
Q

Lesion of the nerve root of CN 4 cause

A

Paralysis of superior oblique m on that side

35
Q

*The occulomotor nucleus is located where

A

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

36
Q

Innervation of the occluomotor n is ipsilateral except for

A

Superior rectus m

37
Q

The Edinger Westphal nucleus sends

A

Preganglionic gibers to the ciliary ganglion

38
Q

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

A

Sphincter pupillae and ciliary mm

39
Q

*Lesions involving occulomotor nucleus nerve generally have same result

A

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

40
Q

The corticonuclear system consists of UMN that influence

A

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

41
Q

The trigeminal nuclei distributes fibers in what way

A

Equal numbers b/l

42
Q

*Muscles in upper 1/2 of face are controlled

A

Both hemispheres

43
Q

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

A

Contralateral hemisphere

44
Q

*A lesion rostral to facial motor nucleus results in

A

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

45
Q

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

A

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

46
Q

*The soft palate/uvula is mainly innervated by

A

Contralateral MN

47
Q

*Lesion of the corticonuclear fibers on the right would cause

A

-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)

48
Q

Genioglossus is innervated how

A

Contralaterally from CN 12

49
Q

Lesions of CN 12 deviate

A

Towards dysfunction

50
Q

A left protruding tongue could be caused by

A

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