Anatomy Cranial Nerves: Modalities, Foramens, Ganglions, Lesions

Olfactory nerve modality

Special sensory - smell

Optic nerve modality

Special sensory - vision

Oculomotor nerve modality

Somatic motor - extraocular muscles (eye movements, upper eyelid elevation)

Parasympathetics - pupil/ciliary muscles

Trochlear nerve modality

Somatic motor - superior oblique muscle

Ophthalmic branch of Trigeminal nerve modality

General sensory - orbit, eye (upper eyelid and forehead)

Maxillary branch of Trigeminal nerve modality

General sensory - nasal cavity, upper teeth

Mandibular branch of Trigeminal nerve modality

General sensory - oral cavity, anterior 2/3 of tongue

Somatic motor - muscles of mastication

Abducens nerve modality

Somatic motor - lateral rectus muscle

Facial nerve modality

General sensory - minimal (small area near ear)

Special sensory - taste for anterior 2/3 of tongue

Somatic motor - muscles of facial expression

Parasympathetic - lacrimal glands, submandibular glands, and sublingual glands

Vestibulocochlear nerve modality

Special sensory - hearing, head position and movement (balance)

Glossopharyngeal nerve modality

General sensory - posterior 1/3 of tongue, pharyngeal wall

Special sensory - taste for posterior 1/3 of tongue

Somatic motor - stylopharyngeus muscle

Parasympathetic - parotid gland

Vagus nerve modality

General sensory - pharynx, larynx

Special sensory - taste (epiglottis)

Somatic motor - muscles in head and neck including pharyngeal/laryngeal muscles

Parasympathetic - thoracic/abdominal

Accessory nerve modality

Somatic motor - contralateral head rotation (sternocleidomastoid muscle), ipsilateral shoulder elevation (trapezius muscle)

Hypoglossal nerve modality

Somatic motor - tongue movements (protraction)

What goes through Cribriform plate?

Transmitted structures:

CN I

What goes through the Optic canal?

Transmitted structures:

CN II

Ophthalmic artery

What goes through the Superior orbital fissure?

Transmitted structures:

CN III

CN IV

CN V₁

CN VI

What goes through the Foramen rotundum?

Transmitted structures:

CN V₂

What does through the Foramen ovale?

Transmitted structures:

CN V₃

Lesser petrosal nerve

What goes through Foramen spinosum

Transmitted structures:

Middle meningeal artery

What is the Foramen lacerum blocked with? What structure runs over it?

Blocked with cartilage that connects the anteromedial tip of the petrous part of the temporal bone to the body of the sphenoid bone

The internal carotid artery runs over the superior surface of that cartilage

What goes through the Internal acoustic meatus?

Transmitted structures:

CN VII

CN VIII

What goes through the Jugular foramen?

Transmitted structures:

CN IX

CN X

CN XI

Internal jugular vein

Inferior petrosal sinus

What goes through the Hypoglossal canal?

Transmitted structures:

CN XII

What goes through the Foramen magnum?

Transmitted structures:

CN XI

Vertebral artery

Ant./Post. Spinal arteries

Medulla oblongata

What goes through the Stylomastoid foramen?

Transmitted structures:

CN VII

What goes through the carotid canal?

Transmitted structures:

Internal carotid artery

Internal carotid sympathetic plexus

Oculomotor nerve ganglion

Ciliary ganglion

Facial nerve ganglia

Pterygopalatine ganglion (nasal secretion, lacrimation)

Submandibular ganglion (salivation)

Geniculate ganglion (gustation and general sensory)

Glossopharyngeal nerve ganglion

Otic ganglion

Trigeminal nerve ganglion

Trigeminal sensory ganglion

Vestibulocochlear nerve ganglia

Cochlear ganglion

Vestibular ganglion

Glossopharyngeal nerve ganglia

Superior/Inferior glossopharyngeal ganglia

Vagus nerve ganglion

Superior/Inferior vagal ganglia

CN I lesion example

Facial trauma with ethmoid bone fracture

CN II lesion example

Neuritis

Retinal conditions

CN III / CN VI lesion example

Cavernous sinus thrombosis

CN V lesion example

Compression of nerve root by neighboring vessels → trigeminal neuralgia

CN V₁ lesion example

Neuritis

CN V₂ lesion example

Maxillary sinus infection

Facial trauma

CN V₃ lesion example

Dentistry iatrogenesis

A common site for HSV-1 infection

CN VII lesion example

Compression from neuroma of acoustic nerve

Skull base fracture

Inflammation at stylomastoid foramen causing Bell palsy

CN VIII lesion example

Skull base fracture

Compression of cochlear nerve by schwannoma of vestibular nerve

CN IX lesion example

Glossopharyngeal neuralgia

Uncommon site for HSV-1 infection

CN X lesion example

Compression of left recurrent laryngeal nerve by tumor in apex of left lung

CN XI lesion example

Neck cancer surgery iatrogenesis