Cranial Nerves Flashcards
Olfactory Nerve Function
Smell
Where does CN1 Emerge?
Underneath the Frontal Lobe
Not considered a ‘true’ cranial nerve because it doesn’t emerge from the brainstem.
Which foramen does CN1 pass through?
Cribriform Plate of the Ethmoid Bone
Tracts form bulbs. Nerves leave the bulb and pass through the ethmoid bone.
CN1 Test of Function?
Ask patient to smell familiar objects
Optic Nerve Function
Vision
Where does CN2 emerge?
Hypothalamus rostral to the infundibulum, as tracts (after optic chiasma)
Which foramen does CN2 pass through?
Optic Canals
CN2 Test of Function?
Test:
Acuity Colour Visual Field Pupillary Light Reflex Fundoscopy
Function of Oculomotor Nerve
Motor to 4/6 Extraocular muscles, Sphincter Pupillae, and Levator Palpabrae Superioris
Where does CN3 emerge?
Interpeduncular Fossa
Which autonomic ganglion is CN3 associated with?
Ciliary Ganglion- autonomic fibres to Sphincter Pupillae and Ciliaris muscles via CNV1.
Foramen of CN3?
Superior Orbital Fissure
CN3 Test of Function?
Follow finger and enquire about signs of double vision
Function of Trochlear Nerve
Motor innervation to Superior Oblique (SO4)
Where does CN4 emerge?
Dorsal Brainstem- Inferior to Inferior Colliculi
Foramen of CN4?
Superior Orbital Fissure
CN4 Test of Function?
Follow finger and enquire about signs of double vision
CN5 Branches
Ophthalmic (V1)
Maxillary (V2)
Mandibular (V3)
Function of Ophthalmic Nerve (V1)
Sensory to skin of Forehead
Autonomic innervation of Sphincter Pupillae and Ciliaris via CILIARY GANGLION
Foramen of V1?
Superior Orbital Fissure
Function of Maxillary Nerve (V2)
Sensation from Maxilla, Upper teeth, Nasal and Oral cavities
Autonomic innervation of Lacrimal Gland via PTERYGOPALATINE ganglion
Foramen of V2?
Foramen Rotundum
Function of Mandibular Nerve (V3)
Sensation from Mandible and Lower Teeth
Sensation from Anterior 2/3 of Tongue
Motor to Muscles of Mastication and Tensor Tympani
Autonomic innervation of Submandibular and Sublingual glands via SUBMANDIBULAR ganglion
Autonomic innervation of Parotid Gland via OTIC ganglion
Foramen of V3
Foramen Ovale
Test of Function of Trigeminal Nerve?
Test sensation over the face
Corneal Reflex
Clench teeth
Jaw Jerk Reflex
Function of Abducens Nerve?
Motor innervation to Lateral Rectus (LR6)
Foramen of CN6?
Superior Orbital Fissure
Test of CN6 Function
Follow finger and enquire about signs of double vision
5 Main branches of the Facial Nerve, and their function?
Temporal Zygomatic Buccal Mandibular Cervical
Motor to the muscles of facial expression
Where does the facial nerve divide into its 5 main branches?
Inside the parotid gland