Cranial Nerves Flashcards
Two parts of skull, how different
Top part –> vault. Intramembranous growth, and is newer evolutionarily. Includes face.
Bottom part –> base. Endochondral growth, older evolutionarily. Where all foramen are for nerves and spinal cord.
Definition of SVE
Special Visceral Efferent, fibers to branchiomeric muscles
Definition of SVA
fiber to taste/smell (gut related senses)
Defintion of SSA
non-gut related senses, vision, balance, hearing
Special Sensory Nerves
I-Olfactory SVA
II- Optic SSA
VIII- Vestibulocochlear SSA
Myotomal nerves
III - Oculomotor GSE, GVE (carries pre-ganglionic parasympathetics to ganglion)
IV - Trochlear GSE
VI - Abducens GSE
XII - Hypoglossal GSE
Branchiomeric nerves
V- Trigeminal SVE, GSA VII- Facial Nerve SVE, SVA, GSA, GVE IX - Glossopharyngeal SVE, SVA, GSA, GVE, GVA X- Vagus SVE, SVA, GSA, GVE, GVA XI - Spinal Accessory Nerve SVE, GSE
CN I: functions, fibers, foramen/path
I-Olfactory SVA
Special Sensory Nerve
Sensory only
Function: Smell
Goes through foramina in cribiform plate of ethmoid bone
** not an actual nerve, actually a brain tract
CN II: functions, fibers, foramen/path
II- Optic SSA
Special Sensory Nerve
Sensory only
Function: Sight
Goes through optic canal in sphenoid bone.
** not an actual nerve, actually a brain tract
CN III: functions, fibers, foramen/path
III - Oculomotor GSE, GVE (carries parasympathetics)
Myotomal Nerve
Motor only
Functions for eye movement GSE and pupillary constriction GVE. Innervates the medial/superior/inferior rectus, inferior oblique, and levator palpebrae superiorus.
Foramen: Superior orbital Fissure
CN IV: functions, fibers, foramen/path
IV - Trochlear GSE Myomotal nerve Motor only Function: eye movement --> muscle is superior oblique Foramen/Path: Superior Orbital Fissure
CN V: functions, fibers
V- Trigeminal SVE, GSA
Branchiomeric nerve from first branchial arch
Sensory and Motor
Functions: Facial sensation GSA, each branch has different fields; chewing/muscles of mastication which are the muscles of the first arch SVE
Three branches: opthalmic, maxillary, mandibular
CN V branches, path and fibers for each branch
Three branches:
V1 - Ophthalmic GSA, through the superior orbital fissure
V2- Maxillary GSA, through foramen rotundum, down through pterygopalatine fossa –>infraorbital groove –> infraorbital foramen
V3 - Mandibular SVE, GSA
Foramen –> through foramen ovale
CN VI: functions, fibers, foramen/path
Abducens Nerve - GSE Myotomal nerve Motor only Function: Eye movement (eye abduction) muscle: lateral rectus Foramen/path: superior orbital fissure
CN VII: functions, fibers
Facial Nerve - SVE, GSA, GVE, SVA
Branchiomeric Nerve - Second Branchial arch
Functions:
Ear Skin Sensation GSA
Facial Expression Muscles SVE
Nasal, Oral, Lacrimal, Submandibular, sublinguinal gland secretomotor control GVE. chorda tympani to submandibular and sublinguinal.
Anterior 2/3 tongue taste SVA
Pathway/branches of facial nerve
motor and sensory roots Enter through internal acoustic meatus, join to form geniculate ganglion. Nerve passes through facial canal. Exits through stylomastoid foramen. Enters parotid gland.
In facial canal gives off branches:
greater petrosal nerve (carries parasympathetic fibers to glands)
stapedius nerve (to stapedius muscle SVE)
chorda tympani (carries SVA fibers to the anterior 2/3 of the tongue)
In the parotid gland gives five branches. All do muscles of facial expression
Temporal
Zygomatic
Buccal
Mandibular
Cervical
Five main branches of facial nerve
Temporal Zygomatic Buccal Mandibular Cervical
Bell’s palsy
Deficit in facial expression due to injury in facial nerve
CN VIII: functions, fibers, foramen/path
Vestibulocochlear SSA
Special Sensory Nerve
Sensory nerve
Functions: Vestibular nerve does balance, Cochlear nerve does hearing
Foramen: Internal Acoustic Meatus –> Doesn’t exit skull
CN IX: functions, fibers, foramen/path
Glossopharyngeal Branchiomeric Nerve of third arch Sensory and Motor SVE, GSA, GVE, SVA, GVA Functions: Pharyngeal muscles SVE Ear Sensation - GSA Secretamotor Parotid gland - GVE Taste posterior 1/3 tongue - SVA Sensation posterior 1/3 tongue - GVA Foramen --> Jugular foramen
CN X: functions, fibers, foramen/path
Branchiomeric Nerve of Fourth arch sensory and motor SVE, GVA, GVE, SVA, GSA Cricothyroid muscle of larynx - SVE ear and larynx sensation - GSA mid and fore Gut sensation - GVA mid and foregut parasympathetic secretomotor control - GVE Taste on epiglottis --> SVA Foramen/path: Jugular foramen
CN XI: functions, fibers, foramen/path
Spinal Accessory Nerve - GSE, GVE
motor
Trapezius and sternocleidomastoid innervated by the spinal root of spinal accessory nerve –> GSE
Larynx muscles except the cricothyroid
–> SVE
foramen/pathway: Spinal root comes up through foramen magum. joins with cranial root. both run with vagus out through jugular foramen. The cranial root is distributed through the recurrent laryngeal nerve (a branch of the vagus).
The spinal root is distributed by itself.
CN XII: functions, fibers, foramen/path
Hypoglossal Nerve Myotomal nerve Motor only GSE Innervates tongue muscles Foramen path: hypoglossal foramen
Auricular sensation
Greater auricular nerve (C2-C3)
Lessser occipital nerve (C2)
CN V, CN VII, CN IX, CN X
All GSA fibers
Taste/smell nerves
CN I - Olfactory IX - Hypoglossal X - Vagus VII - Facial SVA
Nerves that move eye
CN III - Oculomotor
CN IV - Trochlear
CN VI - Abducens
What travels in foramen spinosum
Middle meningeal vessels
meningeal branch of mandibular nerve
Running across cavernous sinuses
internal carotid, abducens (CN VI)
Running in lateral wall of cavernous sinus
oculomotor CN III
trochlear
ophthalmic
maxillary
Branches of the ophthalmic nerve (V2)
lacrimal, nasociliary, frontal (further branching into supraorbital and supratrochlear)
Where are the cavernous sinuses
Next to the lateral aspect of body of sphenoid bones
pupillary light reflex
sensory CN II (optic)
motor CN III (oculomotor)
corneal and lacrimal reflex
sensory ophthalmic nerve (CN V3)
motor facial nerve (VII)
Jaw Jerk reflex
Sensory and Motor both mandibular nerve (V3)
Gag reflex
sensory glossopharyngeus (CN IX) motor CN IX and X
