Cranial Nerves Part II Flashcards Preview

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Flashcards in Cranial Nerves Part II Deck (19):
1

Describe the attachment, foramen, components, nuclues of origin or termination, and main structures innervated for CN VI.

CN VI- Abducens
Attachment- sulcus between pons and medulla on anterior surface
Foramen: superior orbital fissure
Components: GSE

Nucleus of Origin or termination:
1) abducens nucleus (pons)

Main structures innervated
1) motor to lateral rectus muscle (LRG)

2

Where are the 3rd, 4th, and 6th nuclei located?

The 6th nucleus is near the ponto-medullary junction. 3 and 4 are in the midbrain.

3

What is the facial colliculus?

VII coursing over VI (bump)

4

Describe the attachment, foramen, components, nuclues of origin or termination, and main structures innervated for CN VII.

Facial Nerve
Attachment: cerobellomedullary pontine angle
Foramen: internal auditory meatus
Components: GVA, SVA, GSA, GVE, SVE
Nucleus of Origin or Termination:
1) nucleus soliatarius (pons)
2 nuc. solitarius (pons)
3) sens. nuc. of NS (pons)
4) sup. salivatory nuc. (pons)
5) motor nuc. of 7 (pons)

Main structures innervated:
1) deep sens. from soft palate
2) taste buds from ant 2/3 tongue
3) sens. from small part of ear pinna
4) motor to submandibular and sublingual glands, lacrimal glands, glands in nasal mucosa
5) motor to musc. facial expression, post. belly digastric, stylohyoid, stapedius

5

Describe GSA to ear pinna.

GSA to a little ear pinna via the SPINAL TRIGEMINAL NUCLEUS

6

Describe the nuclei locations of CN VII.

All 7 nuclei are in the pons. .—except spinal V for ear pinna (GSA)—which also enters medulla and upper cord

7

Describe the input of neurons that innervate upper and lower face.

The facial motor nucleus contains neurons which innervate the upper face and other neurons which innervate the lower face. Those neurons which innervate upper face muscles receive bilateral cortical input. Those neurons in the facial motor nucleus which innervate the lower face receive input only from the contralateral cortex.

8

Describe the clinical differences between someone suffering a left cortical stroke and a severed right facial nerve.

So—the women on the left has had a left cortical stroke—her forehead and eyes are fine but her lower right face is paralyzed. The person on the right has a severed right facial nerve (lower motor neuron lesion) or Bell’s palsy—and her entire right face is paralyzed.(smooth forehead and inability to close her right eye.

LMN lesion of CN VII (Bell's palsy)
UMN lesion of corticobulbar tract (stroke of internal capsule)

9

Describe what happens if you destroy VII nucleus or nerve.
What happens with a stroke? Why?

Destroy the VII nucleus or nerve, and you have killed the final common pathway or lower motor neurons and total paralysis will occur on the affected side.

upper face is spared with a stroke since upper motor neurons project bilaterally to lower motor neurons destined for the upper face.—Cut the nerve (lower motor neuron) and all is lost.

10

Describe the attachment, foramen, components, nucleus of origin or termination, and main structures innervated for CN VIII.

CN VIII: auditory
Attachment: cerebellomedullary pontine angle
Foramen: internal auditory meatus
Components: 1)SSA a)cochlear, b) vestibular

Nucleus of origin/Termination:
a. cochlear nuclei (medulla)
b. vestibular nuclei (medulla)

Main structures innervated:
a. organ of Corti in cochlear duct
b. semicircular canals, utricle and saccule

11

SLO AIM

SLO AIM

Superior colliculus, lateral geniculate. Optic stuff

Auditory stuff, inferior colliculus, medial geniculate

12

Describe the attachment, foramen, components, nucleus of origin or termination, and main structures innervated for CN IX.

CN IX: Glossopharyngeal
Attachment: post. lateral (olivary) sulcus
Foramen: jugular foramen
Components: GVA, SVA, GSA, GVE, SVE

Nucleus of Origin/Termination:
1) nuc. solitarius (medulla)
2. nuc. solitarius (medulla)
3) sens. nuc. of N5 (medulla)
4. inf. salivatory nuc. (medulla)
5. nuc. ambiguus (medulla)

Main structures innervated:
1) deep sens. from post. tongue, soft palate, pharynx, mucosa of tymp. cavity, post. auditory tube, carotid body and sinus
2) taste buds post 1/3 tongue and adjacent pharynx.
3) gen. sens. from small part of ear pinna and canal
4) parotid salivary gland (secretomotor)
5) stylopharyngeus muscle

13

Where does IX come out near in the medulla?

IX coming out near ICP, which is also called restiform body.

14

Describe the attachment, foramen, components, nucleus of origin or termination, and main structures innervated for CN X.

CN X- Vagus
Attachment: post. lat (olivary) sulcus
Foramen: jugular foramen
Components: GVA, SVA, GSA, GVE, SVE

Nucleus of Origin/ Termination:
1) nuc. solitarius (medulla)
2) nuc. solitarius (medulla)
3) sens. nuc. of N5 (medulla)
4) dors. motor nuc. of 10 (medulla)
5) nuc. ambiguus

Main structures innervated:
1) visc. sens. from pharynx, esophagus, trachea, larynx and abdom. visc.
2) taste buds from epiglottis and glottis
3) sens. from small part of ear pinna, canal, and tymp. membrane
4) thoracic and abdominal viscera
5) muscles of pharynx and larynx, lev. palatini and cricothyroid

15

Describe the attachment, foramen, components, nucleus of origin or termination, and main structures innervated for CN XI.

CN XI: Spinal accessory (spinal roots)
Attachment: upper cervical spinal between post. and ant. roots
Foramen: foramen mag and jugular foramen
Components: 1) SVE
Nucleus of Origin/Termination: 1) accessory nucleus (spinal cord) (C1-C5)
Main structures innervated: 1) motor to sternocleidomastoid and trapezius

16

Describe the attachment, foramen, components, nucleus of origin or termination, and main structures innervated for CN XII.

CN XII- Hypoglossal N.
Attachment: anterior lateral olivary sulcus
Foramen: hypoglossal canal
Components: 1) GSE
Nucleus of Origin/Termination: Hypoglossal nuc. (medulla)
Main structures innervated: intrinsic and extrinsic muscles of tongue (except palatoglossus)

17

What functional component are arch muscles?

SVE

18

Describe branchial arches at weeks 6-8

arch I (mandibular)
muscles of mastication
Trigeminal V

arch II (hyoid)
muscles of facial expression
Facial (VII0

arch III
innervated by glossopharyngeal (IX)

arch IV, VI
muscles of pharynx/larynx
Vagus X

(arch V degenerates in humans)

19

What is the most caudal nucleus in the brainstem?
Where does the spinal accessory nucleus lie?
Describe the nucleus ambiguus.

Hypoglossal nucleus is the most caudal GSE in the brainstem. XI—SVE---The spinal accessory nucleus lies within the cervical spinal cord (C1-C5) in the ventral horn.

The nucleus ambiguus is classically said to provide the "cranial component" of the accessory nerve.

However, the very existence of this cranial component has been recently questioned and seen as contributing exclusively to the vagus nerve. So from this point onward we will declare XI to be purely SVE with its nucleus of origin the spinal accessory nucleus