Cranial nn. ncll. + medulla, pons Flashcards by LV D

List the 7 functional types of cranial nerve nuclei.

somatomotor: voluntary motor, skeletal inn.
general somatosensory: sensory inn. skin/mucosa, joints, muscles
special somatosensory: sensory inn. of retina, inner ear
general visceromotor: symp./parasymp. inn. of guts, involuntary
special visceromotor: inn. of branchial arch mm.
general viscerosensory: sensory inn. of guts, blood vessels
special viscerosensory: sensory inn. of olfactory mucosa, taste buds

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What are the cranial nerve nuclei of n. I, n. II?

n. olfactorius + n. opticus no “real” cranial nerves

n. I = bulbus olfactorius
n. II = corpus geniculatum laterale

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List all somatomotor ncll.

ncl. n. oculomotorii
ncl. n. trochlearis
ncl. n. abducentis
ncl. n. hypoglossi

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List all general somatosensory ncll.

ncl. principalis n. trigemini
ncl. spinalis n. trigemini
ncl. mesencephalicus n. trigemini

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List all special somatosensory ncll.

ncll. cochleares
ncll. vestibulares

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List all general visceromotor ncll.

ncl. salivatorius sup./inf.
ncl. dorsalis n. vagi
ncl. accessorius n. oculomotorii

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List all special visceromotor ncll.

ncl. motorius n. trigemini
ncl. n. facialis
ncl. ambiguus
ncl. n. accessorii

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List all special and general viscerosensory ncll.

ncll. tractus solitarii

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Which cranial nerves do have only 1 nucleus?

Which cranial nerves do have 2+ nuclei?

1 nucleus:

n. I, n. II
somatomotor: n. IV, n. VI, n. XII
n. XI

2+ nuclei:

2: n. III, n. VIII
3: n. VII
4: n. V, IX, X

BUT: altogether 18 (groups of) cranial nerve nuclei

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Generally speaking, where would you locate the somatomotor, somatosensory, visceromotor and viscerosensory ncll.?

most medial: somatomor
more lateral: visceromotor, viscerosensory
most lateral: somatosensory

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What are the nuclei of n. III?

Where can they be found?

2 nuclei:

ncl. n. oculomotorii (1)
ncl. accessorius n. oculomotorii (5)

paramedian at colliculi sup.

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Where does ncl. n. oculomotorii receive its fibers from?

What type of cranial nerve nucleus is it?

To which cranial nerves does it belong?
Function.

What else is important to mention?

= somatomotor

A: from horizontal, vertical visual centres, ncl. n. abducentis
E: n. III to m. levator palpebrae sup. + all outer eye mm. (exc. m. obliquus sup., m. rectus lat.)

BUT: ncl. for m. levator palpebrae sup. unpaired in btw colliculi sup.

₁

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Where does ncl. accessorius n. oculomotorii receive its fibers from?

What type of cranial nerve nucleus is it?

To which cranial nerves does it belong?
Function.

Another name.

also: ncl. Edinger-Westphal
= general visceromotor

A: from area pretectalis + colliculi sup.
E: n. III to m. ciliaris and m. sphincter pupillae (smooth mm.)

₅

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Where does ncl. n. trochlearis receive its fibers from?

What type of cranial nerve nucleus is it?

To which cranial nerves does it belong?
Function.

What else is important to mention?

= somatomotor

A: from horizontal, vertical visual centres
E: n. IV to m. obliquus sup. (look lat. downwards)

BUT: fibers cross to contralat. side

₂

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What are the nuclei of n. V?

Which can be considered as motor, resp. as sensory ncll.?

motor:

ncl. motorius n. trigemini

sensory:

ncl. mesencephalicus n. trigemini
ncl. principalis n. trigemini
ncl. spinalis n. trigemini

BUT: different sensory afferences for sensory fibers

_{9, 16, 17, 18}

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Where does ncl. motorius n. trigemini receive its fibers from?

What type of cranial nerve nucleus is it?

To which cranial nerves does it belong?
Function.

= special visceromotor

A: from motor cortex
E: n. V/3 to mm. of mastication

₉

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Where does ncl. mesencephalicus n. trigemini receive its fibers from?

What type of cranial nerve nucleus is it?

To which cranial nerves does it belong?
Function.

What else is important to mention?

= general somatosensory

A: from n. V/3 (proprioceptive fibers of mm. of mastication)
E: fibers to ncl. motorius n. trigemini

BUT: no peripheral interneuron to mm., own processes → pseudounipolar ganglion

₁₆

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What is the function of ncl. principialis n. trigemini?

What type of cranial nerve nucleus is it?

What is special about it?

Another name.

also: ncl. pontinus n. trigemini
= general somatosensory

A: from nn. V/1-3 (sensible touch from head region = epicritic sensation)
E: via lemniscus trigeminalis to thalamus

some fibers cross to contralat. side

₁₇

Where does ncl. spinalis n. trigemini receive its fibers from?

What type of cranial nerve nucleus is it?

To which cranial nerves does it belong?
Function.

What else is important to mention?

= general somatosensory

A: from n. V/1-3, IX, X (sensation of pain + temperature, crude touch for face)
E: cross via lemniscus medialis to contralat. side, then thalamus

BUT: somatotopic organization

₁₈

Where do the fibers of n. IX that can be found in ncl. spinalis n. trigemini originate from?

general viscerosensory information from

post. 1/3 of tongue
naso-, oropharynx
tuba auditiva
middle ear

_{could be also included in the A section of ncl. spinalis n. trigemini}

Where do the fibers of n. X that can be found in ncl. spinalis n. trigemini originate from?

general viscerosensory information from

larynx
meatus acusticus ext. + parts of ext. ear
r. meningues, innveration dura of post. cranial fossa

Which structure is formed by fibers of ncl. spinalis and ncl. principalis of n. V?

fibers from ncl. spinalis and ncl. principialis of n. V run as tractus trigeminothalamicus to thalamus

→ form leminscus trigeminalis in leminscal trigone

Describe the somatotopic organization of ncl. spinalis n. trigemini.

most rostral → innervation of perioral region
more caudal → innervation of adj. cutaneous regions
most caudal → innervation of even more adj. cutaneous regions

Where does ncl. n. abducentis receive its fibers from?

What type of cranial nerve nucleus is it?

To which cranial nerves does it belong?
Function.

= somatomotor

A: from horizontal visual centers
E: n. VI to m. rectus lateralis (abduction of eye ball)

₃

What are the nuclei of n. VII? Which can be considered as motor, resp. as sensory ncll.?

_motor:_ * **ncl. n. facialis** * **ncl. salivatorius sup.** _sensory:_ * **ncl. solitarius**

Where does ncl. n. facialis receive its fibers from? What type of cranial nerve nucleus is it? To which cranial nerves does it belong? Function. Which morphological feature does it form?

_= special visceromotor_ * *_A:_* from **motorcortex** * _E:_ **n. VII** to mm. of facial expression, m. stylohyoideus, venter post. of m. digastricus, m. stapedius forms characteristic **colliculus facialis** when fibers bend around ncl. n. VI ₁₀

There is a clinically important differentiation of afferent fibers to ncl. n. facialis. Why?

* some fibers resp. for **blinking + mm. of forehead** * remaining fibers resp. for **rest** ⇒ important to destinguish btw central or peripheral facial paresis _ALSO:_ responsible for emotionally triggered mimic expressions, hence independent failure of voluntary/involuntary facial expression

Where does ncl. salivatorius sup. receive its fibers from? What type of cranial nerve nucleus is it? To which cranial nerves does it belong? Function.

_= general visceromotor_ * *_A:_* from **fasciculus longitudinalis post.** from hypothalamus * *_E:_* **n. VII** to lacrimal, nasal, palatine, sublingual, submandibular gland ₆

Where does ncl. solitarius receive its fibers from? What type of cranial nerve nucleus is it? To which cranial nerves does it belong? Why is its function so important?

_= **special viscerosensory** (taste) + **general**_ * *_A:_* **nn. VII, IX, X** from tongue (taste), mechano-/chemoreceptors in sinus caroticus, glomus caroticum, right atrium, arcus aorticus * *_E:_* to **thalamus/veg. brainstem areas** → information abt blood pressure, O₂, CO₂ saturation essential for regulation of breath and BP by medulla and hypothalamus ₁₃

Where do the fibers of n. X that can be found in ncl. solitarius originate from?

_gen. + spec. viscerosensory information from_ * **lung, trachea** * **esophagus, GI tract** * **epiglottis** (taste) _{could be also included in the A section of ncl. solitarius}

What is n. intermedius?

**sensory + parasymp. fibers** of n. facialis | (run seperate from motor fibers)

What are the nuclei of n. VIII? What type of cranial nerve nuclei are they?

_special somatosensory_ * **ncll. cochleares** * **ncll. vestibulares**

Where do ncll. cochleares receive their fibers from? Why plural? What type of cranial nerve nuclei are they? To which cranial nerves do they belong? What else is important to mention?

**ncl. cochlearis ant. + post.** _= special somatosensory_ * *_A:_* from **n. VIII** from cochlea * *_E:_* **central auditory pathway** (corpus trapezoideum, leminscus lat.) to colliculi inf. **_BUT:_** fibers cross to contralat. side after nucleus ₁₅

Where do ncll. vestibulares receive their fibers from? Why plural? What type of cranial nerve nuclei are they? To which cranial nerves do they belong? What else is important to mention?

**ncl. vestibularis sup., inf., med., lat.** _= special somatosensory_ * *_A:_* from **n. VIII** from vestibular organs in inner ear * *_E:_* various *(cf. own card)* ₁₄

What are the most important efferences of ncll. vestibulares? Explain physiologically. Name exceptions!

* **spinal cord, cerebellum:** body posture + balance * **ncll. of eye mm.:** vestibulo-ocular reflex = eyes follow moving objects → fibers are partially directly projection into these structures to provide very rapid processing of information, furthermore: * preoculomotor centers in **formatio reticularis, thalamus:** awareness of body posture + balance

What is tractus vestibulospinalis? Why is it important?

fibers projecting **from ncll. vestibulares directly into spinal cord** ⇒ important for stretch reflexes, e.g. to regain balance (activation of extending mm., inhibition of flexing mm.)

What are the nuclei of n. IX? What type of cranial nerve nuclei are they?

_motor:_ * **ncl. ambiguus** * **ncl. salivatorius inf.** ****_sensory:_ * **ncl. solitarius** * **ncl. spinalis n. trigemini**

Where does ncl. ambiguus receive its fibers from? What type of cranial nerve nucleus is it? To which cranial nerves does it belong? Function.

**_= special visceromotor_** * *_A:_* from **motor cortex** * *_E:_* **n. IX, X** to pharyngeal, laryngeal mm. ₁₁

Where does ncl. salivatorius inf. receive its fibers from? What type of cranial nerve nucleus is it? To which cranial nerves does it belong? Function.

_= general visceromotor_ * *_A:_* **fasciculus long. post.** from hypothalamus * *_E:_* n. IX to **gl. parotis** (parasymp.) ₇

What are the nuclei of n. X? What type of cranial nerve nuclei are they?

_motor:_ * **ncl. ambiguus** * **ncl. dorsalis n. vagi** _sensory:_ * **ncl. solitarius** * **ncl. spinalis n. trigemini**

Where does ncl. dorsalis n. vagi receive its fibers from? What type of cranial nerve nucleus is it? To which cranial nerves does it belong? Function.

**_= general visceromotor_** * *_A:_* from **ncl. solitarius, hypothalamus** * *_E:_* **n. X** covers entire parasymp. innervation of body (exc. glands in head, inner eye mm.) including heart, bronchi - abdomen to left colic flexure ₁₁

Where does ncl. n. accessorii receive its fibers from? What type of cranial nerve nucleus is it? To which cranial nerves does it belong? Function. What is a morphological interesting aspect of this nerve?

_= special visceromotor_ * *_A:_* from **motor cortex** * *_E:_* **n. XI** to mm. sternocleidomastoideus, trapezius **_BUT:_** direct extension of ncl. ambiguus ₁₂

Where does ncl. n. hypoglossi receive its fibers from? What type of cranial nerve nucleus is it? To which cranial nerves does it belong? Function.

_= somatomotor_ * *_A:_* from **motor cortex** * *_E:_* **n. XII** to tongue mm. 4