Page 196 - Edited - Webster HEAD AND NECK - part 1

HN 162
STRUCTURES RELATED TO THE OPTIC CANAL & SUPERIOR

ORBITAL FISSURE

CRANIAL NERVES ENTERING/LEAVING THE ORBIT POSTERIORLY ARE:

THROUGH II (OPTIC)
OPTIC III
CANAL & EYEG UPPER PLUS OPHTHALMIC ARTERY
SUPERIOR IV LID OPHTHALMIC VEINS
ORBITAL VI MOVEMENTS
FISSURE
V1 (OPHTHALMIC TRIGEMINAL)
INFERIOR (MAXILLARY TRIGEMINAL)
ORBITAL FISSURE V2

LEFT ORBIT
SUPERIOR
TENDINOUS ORBITAL
SUPERIOR RING FISSURE LATERAL
OBLIQUEM.
MEDIAL (IV) SUPERIOR V1 LN = lacrimal nerve
RECTUS V1 LN FN = frontal nerve V1
(III) FN
IV
SUPERIOR
OPTIC OPHTHALMIC
CANAL VEIN
III
OPTIC
MEDIAL NERVE III V1 NCN = nasociliary
RECTUS LATERAL RECTUS nerve V1
(III) VI (VI)

INFERIOR OPHTHALMIC VEIN
ALL THREE LAYERS OF
MENINGES INCLUDING
CSF. IN SUBARACHNOID OPHTHALMIC
SPACE. ARTERY & INFERIOR
VEIN OF RECTUS (III)
RETINA
NOTICE that

(A) The OPTIC CANAL conveys the OPTIC NERVE surrounded by all THREE LAYERS OF MENINGES,
including CSF/SUBARACHNOID SPACE. Raised INTRACRANIAL PRESSURE IS ∴ TRANSMITTED TO THE
BACK OF THE EYE (). THE OPHTHALMIC ARTERY IS WITHIN THE MENINGES ∵ THE INTERNAL
CAROTID ARTERY LEAVES THE CAVERNOUS SINUS & PIERCES THE DURA/ARACHNOID BEFORE
GIVING OFF ANY BRANCHES ( ), RUNNING IN SUBARACHNOID SPACE.
(B) The muscles attached to the tendinous ring are supplied by GRANIAL NERVES III & VI
which nerve ∴ enter the lower, enclosed part of the superior orbital fissure i.e. into the
“MUSCLE BASKET.
(c) The NASOCILIARY NERVE (NCN) is from V1 & IS SENSORY to the CORNEA &
SCLERA (SHEET 110) OF THE EYEBALL. It, too, therefore enters the “MUSCLE
BASKET”.
(D) The SUPERIOR OBLIQUE MUSCLE arises outside the tendinous ring, and its nerve- Cr.N IV- ∴
enters outside The MUSCLE BASKET.
(E) The rest of The OPHTHALMIC TRIGEMINAL NERVE (V1) are in search of the forehead &
scalp, and ∵ enters high in the superior orbital fissure - as the lacrimal (LN) & “FRONTIAL (FN)
NERVES.