CN I- Olfactory Nerve

 

Pathway:

• Passes through foramina in cribriform plate of ethmoid bone into anterior cranial fossa

 

Innervations:

• Sensory

  • Special sensory- smell

 

 

 

CN II- Optic Nerve

 

Pathway:

• Passes through optic canal, nerves join to form optic chiasm, fibres from medial side of retina cross to form optic tract

 

Innervations:

• Sensory

  • Special sensory- vision

 

 

 

CN III- Occulomotor Nerve

 

Pathway:

• Emerges from midbrain and exits via superior orbital fissure

 

Innervations:

• Motor

  • Somatic motor- innervates EOMs (LPS, IO, SR, IR, MR)

  • Visceral motor- PNS innervation to ciliaris & constrcitor pupillae 

 

 

CN IV- Trochlear Nerve

 

Pathway:

• Emerges from dorsal surface midbrain and exits via superior orbital fissure

 

Innervations:

• Motor

  • Somatic motor- innervates EOMS (SO)

 

 

 

CN V- Trigeminal Nerve

 

CN V- Trigeminal Nerve can be split into:

1. CN V1- Opthalmic Nerve

2. CN V2- Maxillary Nerve

3. CN V3- Mandibular Nerve

 

CN V1- Opthalmic Nerve

 

Pathway:

• Emerges from pons, travels through trigeminal ganglion and exits via superior orbital fissure

 

Innervations:

• Sensory

  • General sensory- cornea, forehead, scalp, eyelids, nose and mucosa of nasal cavity & sinuses

 

 

CN V2- Maxillary Nerve

 

Pathway:

• Emerges from pons, travels through trigeminal ganglion and exits via foramen rotundum

 

Innervations:

• Sensory

  • General sensory- face over maxilla, maxillary teeth, TMJ, mucosa of nose, maxillary sinuses and palate

 

 

CN V3- Mandibular Nerve

 

Pathway:

• Emerges from pons, travels through trigeminal ganglion and exits via foramen ovale

 

Innervations:

• Sensory

  • General sensory- face over mandible, mandibular teeth, TMJ, mucosa of mouth & anterior 2/3 of tongue

• Motor

  • Somatic motor- MoM, digastric anterior belly, tensor veli palatinii & tensor tympani

 

 

 

CN VI- Abducent Nerve

 

Pathway:

• Emerges between pons and medulla and exits via superior orbital fissure

 

Innervations:

• Motor

  • Somatic motor- innervates EOMS (LR)

 

 

CN VII- Facial Nerve

 

Pathway:

• Emerges between pons and medulla and exits via internal acoustic meatus, facial canal and stylomastoid foramen

 

Innervations:

• Sensory

  • General sensory- external acoustic meatus

  • Special sensory- taste from anteiror 2/3 of tongue & soft palate

• Motor

  • Somatic motor- MoFE & scalp, stapedius, digastric posterior belly

  • Visceral motor- PNS innervation of submadibular & sublingual salivary glands, lacrimal gland

 

 

 

CN VIII- Vestibulocochlear Nerve

 

Pathway:

• Emerges between pons and medulla and exits via internal acoustic meatus, dividing into vestibular and cochlear nerves

 

Innervations:

• Sensory

  • Special sensory

    • Vestibular sensation- from semicircular ducts, utricle, saccule (gives sense of position & movement)

    • Hearing sensation- from spiral organ

 

 

 

CN IX- Glossopharyngeal Nerve

 

Pathway:

• Emerges from medulla & exits via jugular foramen

 

Innervations:

• Sensory

  • General sensory- middle ear & posterior oral cavity

  • Special sensory- taste from posterior 1/3 of tongue

  • Visceral sensory- carotid body & carotid sinus

• Motor

  • Somatic motor- stylopharyngeus

  • Visceral motor- PNS innervation to parotid gland

 

 

 

CN X- Vagus Nerve

 

Pathway:

• Emerges from medulla & exits via jugular foramen, then everywhere!

 

Innervations:

• Sensory

  • General sensory- auricle, external acoustic meatus

  • Special sensory- taste from epiglottis & palate

  • Visceral sensory- pharynx, larynx, trachea, bronchi, heart, oesophagus, stomach, intestine

• Motor

  • Somatic motor- pharynx, larynx, palate & oesophagus

  • Visceral motor- PNS innervation to muscle in bronchi, gut & heart

 

 

 

CN XI- Spinal Accessory Nerve

 

Pathway:

• Emerges from medulla & large spinal roots exits via jugular foramen

 

Innervations:

• Motor

  • Somatic motor- striated muscle of soft palate, pharynx, larynx and to SCM & trapezius

 

 

 

CN XII- Hypolossal Nerve

 

Pathway:

• Emerges from medulla & exits via hypoglossal canal

 

Innervations:

• Motor

  • Somatic motor- to muscles of tongue