Cranial Nerves Pt. 2 Flashcards
Originates: Pontomedullary groove (between the AICA and the Labyrinthe Artery)
Exits: Superior Orbital Fissure
Abducens Nerve (CN VI)
Supplies SVE fibers (motor) to the Lateral Rectus muscle
Abducens Nerve (CN VI)
Lesion in this makes you cross-eyed
Abducens Nerve (CN VI)
Originates: Lateral Pontomedullary Groove. “Cerebellopontine angle”
Exits: Internal Acoustic Meatus
Facial Nerve (CN VII)
Greater Petrosal nerve, Chorda Tympani nerve, and Somatic nerve
Branches of the Facial Nerve
Lips sagging, smoothing of forehead, inability to close the eye, loss of nasolabial fold (skin to lateral aspect of mouth), drooping of mouth.
Bell’s Palsy
Exits via the Petrous portion of the temporal bone.
Greater Petrosal Branch of the Facial nerve (VII)
Supplies GVE fibers (parasympathetic innervation) to the Lacrimal gland, mucus glands in nasal cavity and palate.
Greater Petrosal Branch of the Facial nerve (VII)
Pons of CNS (Superior Salivatory Nucleus) -> Parasympathetic preganglionic fibers of Greater Petrosal n. -> Pterygopalatine Ganglion -> originates new, postganglionic fibers -> hitches a ride via Zygomaticotemporal n. (V2) and Lacrimal n. (V1)-> Nasal & Palatine branches of V2 -> Inc in secretions in Lacrimal glands, nasal cavity, and palate
Greater Petrosal Branch of the Facial Nerve Parasympathetic innervation
The pterygopalatine ganglion sits in this. A small indentation cave that sits within the infratemporal fossa
Pterygopalatine Fossa
Cardiac Plexus → postganglionic sympathetics → Deep Petrosal n. → Joins Greater Petrosal n. to form Vidian n. → Vidian n. runs with Greater Petrosal n. until Pterygopalatine Ganglion → Vidian n. runs right through Ganglion and doesn’t synapse → Lacrimal Gland, nasal cavity, palate
Greater Petrosal Branch of the Facial Nerve Sympathetic innervation
When the Greater Petrosal Nerve joins up with the Deep Petrosal nerve.
Vidian Nerve
Exits Petrous portion of temporal bone via petrotympanic fissure (little slit)
Hitches a ride with Lingual nerve.
-Lingual nerve carries these fibers along with gen sen from V3.
Chorda Tympani Branch of Facial Nerve (CN VII)
Supplies GVE fibers (Parasympathetic) to the Submandibular gland and sublingual gland.
Chorda Tympani Branch of Facial Nerve (CN VII)
Supplies SVA fibers (taste) to anterior 2/3 of tongue
Chorda Tympani Branch of Facial Nerve (CN VII)
Pons of CNS (Superior Salivatory Nucleus → parasympathetic, preganglionic fibers running in Chorda Tympani n. → Submandibular Ganglion → new parasympathetic fibers originate → submandibular and sublingual glands → increase in saliva
Chorda Tympani Branch of Facial Nerve (CN VII) Parasympathetic Innervation
Exits via the Stylomastoid Foramen.
All 5 branches pass through the Parotid Gland.
Somatic Branch of Facial Nerve (CN VII)
Temporal nerve, Zygomatic nerve, Buccal nerve, Mandibular nerve, and Cervical nerve
Branches of the Somatic Branch of the Facial Nerve (CN VII)
Supplies SVE fibers (motor) to the muscles of facial expression (Platysma), Stylohyoid, Posterior belly of digastric, and Stapedius
Somatic Branch of Facial Nerve (CN VII)
Swelling of the Parotid gland = loss of function
Somatic Branch of Facial Nerve (CN VII)
Originates: Lateral Pontomedullary groove. “Cerebellopontine angle”.
Exits: Internal Acoustic Meatus
Vestibulocochlear Nerve (CN VIII)
Cochlear nerve and Vestibular nerve
Branches of the Vestibulocochlear Nerve (CN VIII)
Supplies SSA fibers for hearing
Cochlear nerve (Branch of the Vestibulocochlear Nerve (CN VIII)).
Supplies SVA fibers for equilibrium and balance
Vestibular nerve (Branch of the Vestibulocochlear Nerve (CN VIII)).
Will cause problems with balance, equilibrium, hearing, and possibly muscles of facial expression (same location as CN VII)
Acoustic Neuroma (tumor of CN VIII)
Originates: Where the Pons transition to the Medulla.
Exits: Jugular Foramen
Glossopharyngeal Nerve (CN IX)
Superior Sensory Ganglia, Inferior Sensory Ganglia, Tympanic nerve, and Lesser Petrosal nerve
Branches of the Glossopharyngeal Nerve (CN IX)
Supplies GSA fibers (sensory) to the oropharynx and posterior 1/3 of the tongue
Glossopharyngeal Nerve (CN IX)
Supplies SVA fibers (taste) to the posterior 1/3 of the tongue
Glossopharyngeal Nerve (CN IX)
Supplies SVE fibers (motor) to the Stylopharyngeus muscle
Glossopharyngeal Nerve (CN IX)
Supplies GVA fibers to measure blood pressure from the Carotid Sinus
Glossopharyngeal Nerve (CN IX)
Supplies GVE fibers (parasympathetic innervation) to the Parotid Gland
Glossopharyngeal Nerve (CN IX)
Medulla of CNS → Inferior Salivatory Nucleus → Tympanic n. → Middle Ear, breaks off into Plexus → Lesser Petrosal n. → parasympathetic, preganglionic fibers → Otic Ganglion → postganglionic fibers that run with Auriculotemporal n. (V3) → Parotid Gland
Glossopharyngeal Nerve (CN IX) Parasympathetic innervation
Originates: Medulla posterior to the Olives
Exits: Jugular Foramen
Vagus Nerve (CN X)
Superior Laryngeal Nerve -> Internal and External Branches
Recurrent Laryngeal Nerve
Vagus Nerve (CN X)
Supplies SVE fibers (Somatic Motor) to:
-the pharyngeal muscles (Except for stylopharyngeus m.), -soft palate (except Tensor Veli Palatini - V3)
-Laryngeal Intrinsic Muscles (Cricothyroid, lateral cricoarytenoids, etc. Recurrent Laryngeal does all except Cricothyroid - which is Superior Laryngeal Branch - External Branch)
Vagus Nerve (CN X)
Supplies GSA fibers (sensory) to the External Auditory Canal and Larynx.
Vagus Nerve (CN X)
Supplies GVE fibers (parasympathetic motor) to the thoracic and abdominal viscera all the way down to the Left Colic flexure (where the transverse colon bends on the L side to make the descending colon).
Vagus Nerve (CN X)
Supplies GVA fibers (sensory) to abdominal and thoracic viscera, mainly in peritoneum, pericardium, and pleural membranes
Vagus Nerve (CN X)
Issues with this nerve cause difficulty swallowing or uvula hanging crooked
Vagus Nerve (CN X)
Medulla of CNS → Dorsal Vagal Motor Nucleus → parasympathetic, preganglionic fibers of Vagus Nerve → Tiny Ganglia in walls of the viscera (heart, bronchial tree, stomach, intestines up until L colic flexure)→ originate new, short postganglionic fibers → Viscera of heart, pulmonary airways, GI Tract
Vagus Nerve (CN X) parasympathetic innervation
Originates: C1-C4 as spinal roots, ascends into cranial cavity through foramen magnum
Exits: Jugular Foramen
Spinal Accessory nerve (CN XI)
Supplies SVE fibers (motor) to the Trapezius and Sternocleidomastoid muscles
Spinal Accessory nerve (CN XI)
Test this CN: Turn head side to side; shrug shoulders
Spinal Accessory nerve (CN XI)
Originates: Medulla anterior to the Olives
Exits: Hypoglossal Canal
Hypoglossal nerve (CN XII)
Provides SVE fibers (motor) to the tongue muscles (except Palatoglossus muscle)
Hypoglossal nerve (CN XII)
What are the parasympathetic nerves?
CN 3, 7, 9, 10 and Spinal Cord segments 2-4 (Bowel and bladder emptying)
Moves toward CNS (sensory or dorsal)
Afferent
Moves away from CNS (motor or ventral)
Efferent
Body in general, sensation of skin
Somatic
Guts & internal organs & vessels & glands
Visceral
Small diameter, slow conduction, no myelin. Preganglionic → Postganglionic
Autonomic Motor Fibers
Large diameter, myelinated, rapid conduction. From spinal cord → muscles
Somatic Efferent Fibers
