CRANIAL NERVES PT1

Question 1

Parasympathetic nucleus

Answer 1

Edinger-Westphal Nucleus

Question 1

Form a V shape as they curve over the dorsal aspect of the oculomotor nuclei and fuse anteriorly in the midline

Answer 1

Edinger-Westphal Nucleus

Question 1

Edinger-Westphal Nucleus:

Fibers from pupils run in superficial and medial portion of ________________

Answer 1

oculomotor nerve

Question 1

Axons accompany the other oculomotor fibers to orbit

Synapse with ciliary ganglioEdinger-Westphal Nucleus

Answer 1

Edinger-Westphal Nucleus

Question 1

Short ciliary nerves

Constrictor pupillae and ciliary muscles

Answer 1

Edinger-Westphal Nucleus

Question 1

Receives ______________ for accommodation reflex, and __________________ for the direct and consensual light reflexes

Answer 1

corticonuclear fibers, fibers from pretectal nucleus

Question 1

Oculomotor Nerve Course:

Lie in lateral wall of cavernous sinus

Emerge on the anterior surface of the midbrain

Enter the orbits through superior orbital fissure

Continues to middle cranial fossa

Divides to superior and inferior ramus

Pass forward between PCA and SCA

Answer 1

1.) Emerge on the anterior surface of the midbrain

2.) Pass forward between PCA and SCA

3.) Continues to middle cranial fossa

4.) Lie in lateral wall of cavernous sinus

5.) Divides to superior and inferior ramus

6.) Enter the orbits through superior orbital fissure

Question 1

Oculomotor nerve supplies the Extraocular Muscles:

Answer 1

Levator palpebrae superioris
Superior rectus
Medial rectus
Inferior rectus
Inferior oblique

Question 1

Intrinsic Ocular Muscle - Parasympathetic (ciliary ganglion, short ciliary nerve) supplies:

Answer 1

Constrictor pupillae
Ciliary muscle

Question 2

Purely Motor

GSE

Assist in turning eye ball downward and medially (intorsion and depression) = superior oblique muscle

Answer 2

TROCHLEAR NERVE (CN IV)

Question 3

Situated in anterior part of gray matter that surrounds the cerebral aqueduct or also called

Answer 3

periaqueductal gray matte

Question 4

Situated in anterior part of gray matter that surrounds the cerebral aqueduct

Answer 4

Trochlear Nerve Nucleus

Question 5

Only cranial nerve that exits POSTERIORLY

Acts through the trochlea in the orbit to rotate the top of the eye medially and move it downwards

Answer 5

TROCHLEAR NERVE (CN IV)

Question 6

Nerve fibers pass posteriorly around the central gray matter to the posterior surface of midbrain

Answer 6

Trochlear Nerve Nucleus

Question 7

Superior orbital fissure
Most slender cranial nerve

Answer 7

TROCHLEAR NERVE (CN IV)

Question 8

Receives corticonuclear fibers from both central hemispheres
Receive tectobulbar fibers connecting it to visual cortex

Answer 8

Trochlear Nerve Nucleus

Question 9

Lies inferior to the oculomotor nucleus at the level of the inferior colliculus

Answer 9

Trochlear Nerve Nucleus

Question 10

Receives fibers from MLF connecting it with CN III, VI, and VIII nuclei

Answer 10

Trochlear Nerve Nucleus

Question 11

Arrange the trochlear Nerve Course

Pass forward through middle cranial fossa in lateral wall of the cavernous sinus

Emerges at the posterior surface of midbrain

Immediately decussates at the level of the anterior medullary vellum

Superior oblique

Enters orbit through superior orbital fissure

Turns eye downward and laterally

Answer 11

1.) Emerges at the posterior surface of midbrain

2.) Immediately decussates at the level of the anterior medullary vellum

3.) Pass forward through middle cranial fossa in lateral wall of the cavernous sinus

4.) Enters orbit through superior orbital fissure

5.) Superior oblique

6.) Turns eye downward and laterally

Question 12

Purely motor
GSE
Turns eyeballs laterally (abduction)

Answer 12

ABDUCENS NERVE (CN VI)

Question 13

supplies Lateral rectus for abduction of the eyes

Exits through Superior orbital fissure

Answer 13

ABDUCENS NERVE (CN VI)

Question 14

Abducens Nerve Nucleus receives afferent _________________ from both hemispheres

Answer 14

corticonuclear fibers

Question 15

Abducens Nerve Nucleus receives ___________ from superior colliculus

Answer 15

tectobulbar fibers

Question 16

Beneath the floor of the upper part of the 4th ventricle

Receives fibers from MLF

Answer 16

Abducens Nerve Nucleus

Question 17

Close to the midline and under the facial colliculus

Answer 17

Abducens Nerve Nucleus

Question 18

Arrange abducens Nerve Course: Ascend between pons and clivus Passes anteriorly through pons and emerge in groove between lower border of pons and medulla Passes forward through cavernous sinus, lying below and lateral to internal carotid artery Exit the dura to enter Dorello's canal, running between the dura and skull, under the petroclinoid ligament Enter the orbit through superior orbital fissure Lateral rectus (LR6)

Answer 18

1.) Passes anteriorly through pons and emerge in groove between lower border of pons and medulla 2.) Ascend between pons and clivus 3.) Exit the dura to enter Dorello's canal, running between the dura and skull, under the petroclinoid ligament 4.) Passes forward through cavernous sinus, lying below and lateral to internal carotid artery 5.) Enter the orbit through superior orbital fissure 6.) Lateral rectus (LR6)

Question 19

Largest cranial nerve

Answer 19

Trigeminal Nerve (Cranial Nerve V)

Question 20

3 divisions of trigeminal nerve:

Answer 20

Ophthalmic division (V1) Maxillary division (V2) Mandibular division (V3)

Question 21

Cornea, skin of forehead, scalp, eyelids, and nose; mucous membrane of paranasal sinuses and nasal cavity exits Superior orbital fissure

Answer 21

GSA function of Ophthalmic division (V1)

Question 22

exit of Maxillary division (V2)

Answer 22

Foramen rotundum

Question 22

Skin of face over maxilla; teeth of upper jaw; mucous membrane of nose, maxillary sinus and palate

Answer 22

GSA function of Maxillary division (V2)

Question 23

exit of Ophthalmic division (V1)

Answer 23

Superior orbital fissure

Question 24

exit of Mandibular division (V3)

Answer 24

Foramen ovale

Question 25

skin of cheek, skin over mandible and side of head, teeth of lower jaw and TMJ; mucous membrane of mouth and anterior part of tongue Anterior ⅔ taste of tongue

Answer 25

SVE function of Mandibular division (V3)

Question 26

muscles of mastication; mylohyoid, anterior belly of digastric muscle, tensor veli palatini and tensor tympani Ears have CN 7, 9, 10

Answer 26

GSE function of Mandibular division (V3)

Question 27

4 nuclei of trigeminal nerve :

Answer 27

Main sensory nucleus Spinal nucleus Mesencephalic nucleus Motor nucleus

Question 28

Trigeminal nuclei receive GSA inputs from CN V, VII, IX and X Touch, pain, temperature, position and vibration sense for face, sinuses and meninges

Answer 28

Trigeminal Nuclear Complex

Question 29

From CN V - sensation for face, mouth, anterior 2/3 of tongue, nasal sinuses and supratentorial dura Smaller inputs from CN VII, IX and X – sensation for part of external ear

Answer 29

Trigeminal Nuclear Complex

Question 30

CN IX sensation to middle ear, posterior 2/3 of tongue and pharynx CN X – infratentorial dura and some pharyngeal sensation

Answer 30

Trigeminal Nuclear Complex

Question 30

Chief or Principal Sensory Nucleus Lies in posterior part of pons, lateral to motor nucleus

Answer 30

Main Sensory Nucleus

Question 31

Continuous below with spinal nucleus Above with mesencephalic

Answer 31

Main Sensory Nucleus

Question 32

Fine touch, dental pressure through trigeminal lemniscus to VPM Trigeminal nucleus crosses to opposite side of the brainstem to ascend with the medial lemniscus towards the thalamus to VPM. Tertiary neurons travel to face area of primary somatosensory cortex

Answer 32

Main Sensory Nucleus

Question 33

dorsal trigeminothalamic tract – does not decussate and travel to ipsilateral VPM conveying touch and pressure sensation from oral cavity including teeth

Answer 33

Smaller pathway – for main sensory nucleus of trigeminal nerve

Question 34

Continuous superiorly with main sensory nucleus in pons

Answer 34

Spinal Nucleus

Question 34

Composed of a column of unipolar cells in the lateral part of the periaqueductal gray matter

Answer 34

Mesencephalic Nucleus

Question 35

Extends inferiorly as far as the main sensory nucleus

Answer 35

Mesencephalic Nucleus

Question 36

Extends inferiorly through the whole length of the medulla and into upper part of the spinal cord as far as C2 segment

Answer 36

Spinal Nucleus

Question 37

Proprioception from muscles of mastication, tongue and possibly from EOMs

Answer 37

Mesencephalic Nucleus

Question 38

Crude touch, pain and temperature through trigeminothalamic tract to VPM Fibers enter lateral pons with trigeminal nerve and descend in spinal trigeminal tract to synapse with spinal nucleus

Answer 38

Spinal Nucleus

Question 39

Located in upper to mid pons near the level of trigeminal nerve exit from brainstem Situated in the pons medial to the main sensory nucleus

Answer 39

Motor Nucleus

Question 40

Secondary neurons from spinal nucleus cross to ascend as trigeminothalamic tract (ventral trigeminothalamic tract)

Answer 40

Spinal Nucleus

Question 41

Synapse with VPM and tertiary neuronal fibers travel in internal capsule to reach primary somatosensory cortex

Answer 41

Spinal Nucleus

Question 42

uns inferomedial to trigeminal ganglion along the floor of Meckel's cave then joins V3 to exit via foramen ovale

Answer 42

Motor Root of motor nucleus of trigeminal nerve

Question 43

Supplies muscles of mastication and smaller muscles (tensor tympani, tensor veli palatini, mylohyoid and anterior belly of digastric)

Answer 43

Motor Nucleus

Question 44

Rests on upper surface of petrous part of the temporal bone in middle cranial fossa Pass forward out of the posterior cranial fossa Leaves anterior aspect of pons as small motor and large sensory root Large sensory root expands to form trigeminal ganglion Ophthalmic, maxillary and mandibular nerves arise from anterior border of the ganglion V1 – sensory – superior orbital fissure V2 – sensory – foramen rotundum V3 – motor and sensory – foramen ovale

Answer 44

1.) Leaves anterior aspect of pons as small motor and large sensory root 2.) Pass forward out of the posterior cranial fossa 3.) Rests on upper surface of petrous part of the temporal bone in middle cranial fossa 4.) Large sensory root expands to form trigeminal ganglion 5.) Ophthalmic, maxillary and mandibular nerves arise from anterior border of the ganglion 6.) V1 – sensory – superior orbital fissure V2 – sensory – foramen rotundum V3 – motor and sensory – foramen ovale

Question 44

Semilunar or gasserian ganglion

Answer 44

Trigeminal Ganglion

Question 45

Sensory ganglion of trigeminal nerve

Answer 45

Trigeminal Ganglion

Question 46

Lies in Meckel's cave - small fossa just posterior and inferolateral to cavernous sinus

Answer 46

Trigeminal Ganglion