OUTLINE  Superior orbital fissure

A. ANATOMY  Optic canal foramen

B. FUNCTION  Foramen Rotundum
 Foramen Ovale
Notes from Snell’s Clinical View and  Foramen Spinosum
videos from TCML Videos.
 Foramen Lacerum
 Carotid canal shares opening
Foramen in Cranial Fossa with foramen lacerum.
 Optic canal present in lesser wing
of sphenoid → mcq .
Anterior Cranial fossa (TCML)
 Mn → L in optic canal – L in
4 foramen Lesser
 Foramen Caecum
 Anterior Ethmoidal foramen
 Cribriform plate
 Posterior Ethmoidal foramen
 Mn → FACP rhymes with fact

Posterior Cranial Fossa

Mn → What to look in girls →
Innocence, Jugs, Height & Face
Internal acoustic meatus
 aka Internal auditory meatus
 aka internal auditory canal
 Both internal auditory meatus &
external auditory meatus → part of
Middle Cranial fossa temporal bone → mcq.
Jugular foramen
Mn → Super Old Rotund Owls Spin
Lazily Hypo Glossal canal
  Foramen Magnum

Contents of Foramina

Anterior Cranial Fossa (TCML) Superior part

– Foramen Caecum  1 Vein

 Emissary vein  2 artery

 To superior sagittal sinus from  3 nerves

upper part of nose → mcq  Vein
– Anterior Ethmoidal foramen  Superior ophthalmic vein
 Anterior ethmoidal vessels & nerves  Artery
 Branch of ophthalmic div of CN V  Lacrimal artery
– Cribriform plate  Recurrent branch of lacrimal artery
 Olfactory nerve – CN I  Nerves
– Posterior Ethmoidal Foramen →  Mn → LFT

 Posterior ethmoidal vessels & nerve.  Lacrimal Nerve – Ophthalmic div of

Trigeminal
Middle Cranial Fossa (No video)  Frontal Nerve – Ophthalmic Div Of
Trigeminal
Mn → CN 2 to CN 6 passes from MCF.
 Trochlear nerve → CN IV
– Superior orbital fissure
Middle part
 Divided into 3 compartments
 5 nerves
 Has everything related to eye.
 Nerves
 Superior Division of oculomotor
nerve – CN III
 Naso Ciliary nerve

 Sympathetic division of ciliary

ganglion
 Inferior Division of oculomotor
nerve – CN III
 Abducens nerve
  Mn → sms k baad → SNS IA

Inferior part
 1 vein

 Vein
 Inferior Ophthalmic vein

– For simplicity →
 CN III IV V1 VI
x--------------------------x

– Optic canal foramen

 Optic Nerve – CN II Posterior Cranial Fossa
 Ophthalmic artery. For ease → CN VII to XII
– Internal Acoustic meatus
– Foramen Rotundum  CN 7 + CN 8
 CN V2 - Maxillary branch  Internal Auditory vessels aka
Labyrinthine vessels
– Foramen Ovale – Jugular foramen

 Mn → MALE  Jugular means → Throat

 CN – V3 Mandibular branch  3 compartments
 Ant
 Accessory Middle meningeal artery
 Mid
 Lesser petrosal nerve
 Post
 Emissary vein
 Emissary vein → drain pterygoid  Anterior
plexus to cavernous sinus.  Inferior petrosal sinus.

 Middle
– Foramen Spinosum  CN 9 10 11

 Mn → Spine in the middle →  Mn – Jug 3 letters 3 nerves.

foramen spinosum → middle  Posterior

meningeal artery.  Junction of sigmoid sinus to
 Middle Meningeal artery Internal Jugular vein → mcq.
 Nervous Spinosum →  Mcq →
 Branch of mandibular division of  Internal jugular vein when it
trigeminal nerve. passes from jugular foramen, its
immediate relation is with Internal
– Foramen Lacerum carotid artery (no pic)
 Formed by union of 3 bones
 Petrous part of temporal bone

 Greater wing of sphenoid

 Basal region of Occipital bone

 Lower part closes with cartilage after

birth.
 Upper part →
 Common for both

 Carotid canal

 Foramen Lacerum

 Allows passage of the internal

carotid artery from the carotid – Hypo glossal canal
canal into the cranial cavity.  aka → Anterior condylar canal
  CN 12

– Foramen Magnum
 aka → Posterior condylar canal
 2 compartments → front & behind
spinal cord.
 Anterior

 Posterior

 Anterior Compartment
 3 ligaments

 Apical ligament of Dens

 Upper longitudinal band of

curate ligament
 Membrana tectoria

 Posterior compartment
 Medulla oblongata + 3 meninges

 Arteries (in pic)

 Spinal part / root of CN XI

 Vertebral venous plexus → mcq

 Other Deets of Foramina

Anterior Cranial Fossa

– Bones
 Frontal bone → Anterior and lateral
direction
 Ethmoid bone → Midline
 Two parts of the Sphenoid bone →
Posteriorly
 Body → midline

 Lesser wings → Laterally

Middle Cranial Fossa

– Bones
 Parts of Sphenoid bone
 Body of sphenoid

 Greater wing of sphenoid.

Temporal bone
Lesser wing of sphenoid form


process called Anterior clinoid
process. – Body of Sphenoid
 Tentorium cerebelli attaches to  Hypophyseal fossa
anterior clinoid process → mcq  deep central area of body of
sphenoid bone.
 aka Sella turcica

 containing the pituitary gland

 Tuberculum Sellae
 Anterior wall of sella turcica

 Dorsum sellae
 Posterior wall of the sella turcica

 The body of the sphenoid contains the

sphenoid air sinuses,
 Lined with mucous membrane,
communicate with the nasal cavity,
and serve as Voice resonators.
 Posterior Clinoid process
 Points of attachment like Anterior
clinoid processes for tentorium
cerebelli.

– Cribriform plate
 Part of ethmoid bone located in base
of skull is called CP.
 Central projection of cribriform plate
→ crista galli
 Falx cerebri attaches to crista galli
  Middle cranial fossa
 Maxillary division of trigeminal
nerve.
 Posterior Cranial fossa
 Dura matter supplied by →

 Upper 3 Cervical spinal nerves

 Hypoglossal nerve

 Recurrent branch of Vagus nerve.

– Petrous part of temporal bone → forms

base of middle cranial fossa.
Posterior Cranial Fossa


– Damage to Jugular foramen

– Bones
 Gag reflex
Mainly formed by
 CN IX X XI leave from jugular foramen
Parts of Temporal bones

Parts of Occipital bones
– Internal jugular foramen
Sigmoid sinus also leaves via this


foramen.
– Middle cranial fossa
Base of MCF → most number of


foramina → makes it the weakest

foramina → most common site of
fracture.
– Facial Nerve
Note Facial nerve exits skull 2 times


 Internal acoustic meatus

 Stylomastoid foramen.

Pearls – Hanging damage structure ???

– Superior orbital fissure → – Valve of Hasner ??
 communication between MCF & orbit – Nasolacrimal duct open →
 present between greater & lesser – Temporalis → main muscles of chewing
wing of sphenoid. – Wood ruff area ??
– Posterior Cranial Fossa – Hangman fracture
 Roof formed by Tentorium cerebelli. –
– Sinusitis –
 Orbital cellulitis most commonly –
occurs when a bacterial infection –
spreads from the paranasal sinuses
–
into the orbit.
–
 Most common sinus through which
spread occurs → Ethmoid sinus. –
– Dura Mater Nerve Supply –
 Anterior cranial fossa –
 Primarily by anterior and posterior –
ethmoidal nerves – branches of –
ophthalmic division of trigeminal –
nerve.
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o Rough
Efferent fibers (out of the
cerebellum)
Middle cerebellar peduncles
Pathways associated with Cerebellum

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