Page 160 - Edited - Webster HEAD AND NECK - part 1

χ = optic chiasma (in the

Anterior fossa: CrN I chiasmatic sulcus of the
body of the sphenoid -
Middle fossa: CrNs II, III, IV, V & VI SHEET 77): optic nerves

Notice that each division of the (Cr N II) exchange 50%
trigeminal nerve (V₁, V₂, V₃) I: bundles of olfactory of axons with each other,

exits/enters through a different n. axons create the just in front of the

aperture, and that V₁ (ophthalmic) cribriform plates. pituitary fossa (PF)

shares its aperture (the superior containing pituitary gland.

orbital fissure) with III, IV & VI. Pituitary tumours can

Also, that these three nerves crush the optic chiasma.
(III, IV, V₁) together with

III oculomotor
V₁ & V₂ have to negotiate Optic IV trochlear SUPERIOR
ORBITAL ISSURE
the cavernous venous sinus. canal VI abducent → ORBIT
Posterior fossa: VII, EXITS & ENTRANCES FOR CRANIAL NERVES

VIII, IX, X, XI, XII. ophthalmic V₁ HN 131

Notice that although VI

arises in the posterior maxillary V2 FORAMEN CAVERNOUS VENOUS
ROTUNDUM
SINUS: note rel. to
fossa it does not leave to PTERYGOPALATINE superior orbital fissure &
directly from it. Also mandibular V3 FOSSA (behind maxilla) foramen rotundum.

spinal XI. IX glossopharyngeal
Nervus FORAMEN INFRATEMPORAL
spinosus X Vagus OVALE TO & REGION
FROM
Trigeminal XI cranial VI abducent FORAMEN (medial to ramus of
accessory
(sensory) ganglion SPINOSUM mandible)

V trigeminal XII hypoglossal INTERNAL AUDITORY

(ACOUSTIC) MEATUS
(into/out of petrous temporal
bone: ear; stylomastoid
FORAMEN foramen)
VIII Vestibulo- MAGNUM JUGULAR (to & from NECK) K.E.W.
cochlear XI (Spinal FORAMEN
VII Facial accessory) HYPOGLOSSAL CANAL