Cranial Nerves Flashcards
Pathway of CN I nerve:
Olfactory nerve:
pass through foraminifera in cribriform plate of ethmoid bone and enter olfactory bulb in the anterior cranial fossa.
Components of CN I
Special sensory - smell
Pathway of CN II
Optic nerve:
enters via optic canal, nerves join to form optic chasm, fibres from medial half of each retina cross to form optic tract.
Components of CN II
Special sensory - vision
Pathway of CN III
Oculomotor:
Emerges from midbrain and exits via superior orbital fissure
Components of CN III
Somatic motor - extra ocular muscles and eyelid
visceral motor - parasympathetic to pupil causing constriction and to ciliary muscle causing accommodation of the lens.
MOVEMENTS OF EYES
Components of CN IV
Trochlear:
somatic motor - extra ocular muscle
Pathway of CN V1
Trigeminal (opthalmic)
emerges from pons, travels through the trigeminal ganglion and exits via superior orbital fissure
Components of CN V1
general sensory - from forehead,scalp,nose,eyelids and mucosa of nasal cavity and sinuses.
Pathway of CN V2
Trigeminal (maxillary):
exits via the foramen rotundum
Components of CN V2
General sensory - from face over maxilla, maxillary teeth, temperomandibular joint, mucosa of nose, maxillary sinuses and palate
Pathway CN V3
Trigeminal (mandibular):
exits via the foramen oval
Chewing
Pathway of CN VI
emerges between pons and medulla and exits via the superior orbital fissure
Components of CN VI
somatic motor - extra ocular muscle
Pathway of CN VII
Facial Nerve:
emerges between pons and medulla and exits via internal acoustic meatus, facial canal and stylomastoid foramen
Components of CN VII
somatic motor - muscles of facial expression
visceral motor - parasympathetic innervation of submandibular and sublingual salivary glands
special sensory - taste from anterior 2/3rd of tongue
Pathway of CN VIII
Vestibulocochlear:
emerges between pons and medulla and exits via internal acoustic meatus, dividing into vestibular and cochlear nerves
Components of CN VIII
Special sensory - vestibular sensation from semicircular ducts, utricle. Hearing.
Pathway of CN X
Vagus:
emerges from medulla and exits via jugular foramen, then everywhere
Components of CN X
special sensory - taste
general sensory - sensation from auricle
visceral sensory - from pharynx, larynx, trachea…
visceral motor - parasympathetic innervation muscle in bronchi, gut, heart
somatic motor - pharynx, larynx
Pathway of CN IX
Glossopharyngeal:
emerges from medulla and exits via jugular foramen
Components of CN IX
special sensory - taste from posterior 3rd of tongue
general sensory - cutaneous sensations from middle ear
visceral sensory - sensation from carotid body & carotid sinus
visceral motor - parasympathetic innervation of parotid gland
somatic motor - to stylopharyngeus, helps with swallowing
Pathway of CN XI
Accessory: small cranial (medulla) and large spinal roots exit via jugular foramen.
Components of CN XI
Somatic motor - striated muscle of soft palate, pharynx and larynx, and to sternocleidomastoid and trapezius
Pathway CN XII
Hypoglossal:
emerges from medulla and exits through the hypoglossal canal
Components CN XII
somatic motor - to muscles of tongue
Pathway of CN IV
emerges from dorsal surface of the mid brain and exits via the superior orbital fissure
