Cranial Nerves Pt. 1 Flashcards
Cranial Nerve I
Olfactory Nerve
Cranial Nerve II
Optic Nerve
Cranial Nerve III
Oculomotor Nerve
Cranial Nerve IV
Trochlear Nerve
Cranial Nerve V
Trigeminal Nerve
Cranial Nerve VI
Abducens Nerve
Cranial Nerve VII
Facial Nerve
Cranial Nerve VIII
Vestibulocochlear Nerve
Cranial Nerve IX
Glossopharyngeal Nerve
Cranial Nerve X
Vagus Nerve
Cranial Nerve XI
Spinal Accessory Nerve
Cranial Nerve XII
Hypoglossal Nerve
Originates: Interior Frontal Lobe
Exits: Cribriform Plate
Olfactory Nerve (CN I)
Branch of CN I:
-Supplies temporal lobe and primary olfactory area (Piriform Cortex)
Lateral Striae
Branch of CN I:
-Supplies the para-olfactory area and connects to the Limbic System.
-Also has other fibers that project to the Anterior Commissure and cross over to the Olfactory area on the other side of the brain
Medial Striae
Primary Olfactory area, made up on the Uncus and the Rostral end of the parahippocampus.
Piriform Cortex
Which is the only sensory nerve that does not go through the Thalamus?
Olfactory Nerve (CN I)
Olfactory Fascicles -> Cribriform Plate -> cranial cavity -> olfactory bulb -> olfactory tract -> olfactory trigone -> Medial and Lateral striae
Olfactory Nerve (CN I)
Usually take something with a strong odor (ammonia), if they withdraw/ retract when it is passed under their nostrils, can tell that they can smell the substance.
Olfactory Nerve (CN I)
Originates: Ventral Midbrain
Exits: Optic Canal
Optic Nerve (CN II)
SSA fibers: Vision
Temporal = lateral
Nasal = medial
Optic Nerve (CN II)
Which visual fibers cross?
Nasal fibers
Which visual fibers do not cross?
Temporal fibers
R Visual Cortex (brain) sees what visual field?
Left visual field
L Visual Cortex (brain) sees what visual field?
Right visual field
Optic Nerve -> optic canal (enters cranial cavity) -> Optic chiasm (crossing occurs) -> optic tract -> Lateral Geniculate Nucleus -> optic Radiations -> Occipital Visual Cortex
Optic Nerve (CN II)
A lesion in the right visual cortex will cause what?
Absent Left visual field
Test of visual eye fields
Testing for Optic Nerve (CN II)
Originates: Interpeduncular fossa
Exits: Superior Orbital Fissure
Oculomotor Nerve (CN III)
Which two arteries surround the Oculomotor Nerve?
Superior Cerebellar Artery and Posterior Cerebral Artery
What are the two SVE branches of the Oculomotor Nerve?
Superior and Inferior Branches.
What are the two muscles innervated by GVE (autonomic) fibers of the Oculomotor Nerve?
Ciliary muscle and Constrictor Pupillae muscle
What does the Superior Branch of the Oculomotor Nerve Innervate?
Levator Palpebral Superioris muscle and Superior Rectus muscle
What does the Inferior Branch of the Oculomotor Nerve Innervate?
Inferior Rectus muscle, inferior oblique muscle, and medial rectus muscle
Eye movement, elevate eyelids, pupillary control
Function of Oculomotor Nerve (CN III)
Direct Light Reflex: shine light in eye = pupil constriction
Consensual Light Reflex: will see a small constriction in the pupil of the opposite eye
Test for Oculomotor Nerve (CN III)
Compresses the Oculomotor nerve, causing a dilated “blown” pupil on the ipsilateral side of the lesion. Will also see drooping of eyelid.
Uncal Herniation
Midbrain of CNS -> Accessory Oculomotor Nucleus (Edinger-Westphal) -> parasympathetic preganglionic axons of CN III -> Ciliary Ganglion (right over Optic n.) -> originates new, postganglionic axons: Short Ciliary nerves -> Ciliary m. or Constrictor Pupillae m. -> Pupil constriction/dilation
Oculomotor Nerve (CN III) Parasympathetic Innervation
Originates: Dorsal Aspect of Brainstem (under/behind the inferior colliculi). Wraps around pons/midbrain
Exits: Superior Orbital Fissure
Trochlear Nerve (CN IV)
Supplies SVE fibers for the Superior Oblique Muscle
Trochlear Nerve (CN IV)
Only CN that crosses at the superior medullary velum
Trochlear Nerve (CN IV)
“Follow my finger”
Test for Trochlear Nerve (CN IV)
Originates: Ventrolateral Pons
Exits: Superior Orbital Fissure (1), Foramen Rotundum (2), Foramen Ovale (3)
Trigeminal Nerve (CN V)
1: Ophthalmic
2: Maxillary
3: Mandibular
Trigeminal Nerve (CN V) Branches
Sensory fibers for the Trigeminal Nerve originate here
Trigeminal Ganglion
Lightly brush something on someone’s face or see if patient can clench teeth equally
Test for Trigeminal Nerve (CN V)
Originates: Ventrolateral pons
Exits: Superior Orbital Fissure
Ophthalmic nerve (V1)
Tentorial nerve, Frontral nerve, Lacrimal nerve, and Nasociliary nerve
Branches of the Ophthalmic nerve (V1)
Supplies GSA (sensory) to the Tentorium Cerebelli (what separates the cerebellum from the occipital lobe)
Tentorial Nerve (branch of Opthalmic nerve V1)
Has the Supraorbital branch and the Supratrochlear branch
Frontal Nerve (branch of Ophthalmic Nerve V1)
Supplies GSA (sensory) to the upper forehead, scalp to vertex, and frontal sinuses
Supraorbital Branch of the Frontal Nerve (branch of Ophthalmic Nerve V1)
Supplies GSA (sensory) to the lower forehead.
Supratrochlear Branch of the Frontal Nerve (branch of Ophthalmic Nerve V1)
Long Ciliary nerves, Anterior Ethmoidal Nerve, Posterior Ethmoidal Nerve, and Infratrochlear nerve
Branches of the Nasociliary Nerve (Branch of Ophthalmic Nerve V1)
Supplies GSA (Sensory) to the cornea, conjunctiva, and sclera
Long Ciliary Nerve (Branch of the Nasociliary Nerve - Branch of the Ophthalmic Nerve)
Supplies GSA (sensory) to the vestibule of the nose and anterior nasal cavity.
Anterior Ethmoidal Nerve (Branch of the Nasociliary Nerve - Branch of the Ophthalmic Nerve)
Supplies GSA (sensory) to the Sphenoid Sinus and the Ethmoidal Air cells
Posterior Ethmoidal Nerve (Branch of the Nasociliary Nerve - Branch of the Ophthalmic Nerve)
Supplies GSA (sensory) to the upper eyelid
Infratrochlear Nerve (Branch of the Nasociliary Nerve - Branch of the Ophthalmic Nerve)
Supplies GSA (sensory) to the forehead, scalp to vertex (crown), conjunctiva, sclera, skin over nose, upper eyelid, ethmoidal air cells, and frontal & Sphenoid sinuses
Ophthalmic Nerve (V1)
Originates: Ventrolateral Pons
Exits: Foramen Rotundum
Maxillary Nerve (V2)
Meningeal Nerve, Pterygopalatine nerve, Nasopalatine nerve, Lateral Posterior Superior Nasal nerve, Pharyngeal Nerve, Superior Alveolar Nerve, Zygomaticotemporal nerve, and infraorbital nerve
Branches of the Maxillary Nerve (V2)
Supplies GSA (Sensory) to the Dura Mater
Meningeal Nerve (Branch of the Maxillary Nerve V2)
Branches into the Greater Palatine nerve (GSA-sensory to the hard palate) and the Lesser Palatine nerve (GSA-sensory to the soft palate)
Pterygopalatine nerve (Branch of the Maxillary Nerve V2)
Supplies GSA fibers (sensory) to the nasal septum
Nasopalatine nerve (Branch of the Maxillary Nerve V2)
Supplies GSA fibers (sensory) to the lateral nasal cavity
Lateral Posterior Superior Nasal nerve (Branch of the Maxillary Nerve V2)
Supplies GSA fibers (Sensory) to the Nasopharynx
Pharyngeal nerve (Branch of the Maxillary Nerve V2)
Supplies GSA fibers (sensory) to the upper molars (posterior), upper premolars (middle), and upper canines and incisors (anterior)
Superior Alveolar Nerve (Branch of the Maxillary Nerve V2)
Supplies GSA fibers (Sensory) to the zygomatic portion of the face and anterior temple
Zygomaticotemporal nerve (Branch of the Maxillary Nerve V2)
Supplies GSA fibers (sensory) to the middle face (maxilla)
Infraorbital nerve (Branch of the Maxillary Nerve V2)
Supplies GSA fibers (sensory) to the alae (sides) of nose, middle face (skin over maxilla), and anterior temple (lower eyelid, maxillary sinus, nasopharynx, nasal cavity, palate, and upper teeth)
Maxillary Nerve (V2)
Originates: Ventrolateral pons
Exits: Foramen Ovale
Mandibular Nerve (V3)
Supplies GSA fibers (Sensory) to the chin and lower lip; nerve to the mylohyoid
Inferior Alveolar Nerve (Branch of the Mandibular Nerve V3)
Inferior Alveolar Nerve, Lingual Nerve, Auriculotemporal Nerve, and Buccal Nerve
Sensory Branches of the Mandibular Nerve (V3)
Carries parasympathetic innervation to the Parotid Gland. Surrounds the Middle Meningeal Artery
Auriculotemporal Nerve (Branch of the Mandibular Nerve V3)
Supplies GSA fibers (Sensory) to the cheek/buccal area
Buccal Nerve (Branch of the Mandibular Nerve V3)
Supplies SVE fibers (motor) to the Anterior Belly of the Digastric, Mylohyoid muscle, Tensor Veli Palatini muscle, Tensor Tympani muscle, Masseter muscle, Temporalis muscle, and Medial & Lateral Pterygoid muscles.
Mandibular Nerve (V3)
Supplies GSA fibers (Sensory) to the chin, jaw, posterior temple (buccal area, anterior 2/3 of the tongue, floor of the mouth/teeth, and TMJ)
Mandibular Nerve (V3)