The Skull
Cranium:
Anterior View: includes the frontal bone, zygomatic
bones, nasal bones, maxilla, and mandible
Lateral View: includes lateral calvaria bones, lateral
facial bones, and the mandible
Superior View: includes frontal, parietal, and occipital
bones
Inferior View: includes maxilla, zygomatic, palatine,
sphenoid, temporal, and occipital bones
External Foramina:
Foramen
Supra-orbital foramen
Infra-orbital foramen
Mental foramen
Zygomaticofacial foramen
Parietal foramen
Incisive foramen
Greater palatine foramen
Lesser palatine foramen
Pterygoid canal
Carotid canal
Stylomastoid foramen
Bone
Frontal
Maxillary
Mandible
Zygomatic
Parietal
Maxilla
Palatine
Palatine
Sphenoid
Temporal
Temporal
Contents
Supra-orbital nerve and vessels
Infra-orbital nerve and vessels
Mental nerve and vessels
Zygomaticofacial nerve
Emissary veins
Nasopalatine nerve, sphenopalatine vessels
Greater palatine nerve and vessels
Lesser palatine nerve and vessels
pterygoid nerve and vessels
Internal carotid artery and nerve plexus
Facial Nerve [VII]
Landmarks of the Skull:
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Bregma: intersection of coronal and sagittal sutures
Lambda: intersection between lambdoid and sagittal
sutures
Glabella: depression of frontal bone between the
superciliary arches
Nasion: articulation of nasal and frontal bones
Pterion: junction of the frontal, parietal, temporal,
and sphenoid bones. This area is of great relevance
in skull fractures because the bone in this region is
thin and overlies the anterior division of the middle
meningeal artery
Cranial Cavity:
Roof of the Cranial Cavity: the calvaria
-
-
Consists of the frontal, parietal, and occipital bones
Contains sutures between bones:
o Coronal suture: between frontal and parietal bones
o Sagittal suture: between paired parietal bones
o Lambdoid suture: between parietal and occipital bones, may contain sutural (wormian)
bones
Frontal Crest: midline ridge of bone on the frontal bone  acts as attachment point for falx
cerebri (dura mater that separates the two cerebral hemispheres)
Groove for Superior Sagittal Sinus
Grooves for Meningeal vessels
Granular Foveolae: mark locations of arachnoid granulations (involved in CSF reabsorption)
Floor of the Cranial Cavity:
-
-
Anterior cranial fossa: parts of frontal, ethmoid, and
sphenoid bones
o Filled by frontal lobes of cerebral hemispheres
o Crista galli: located on the ethmoid, acts as another
point of attachment for the falx cerebri
o Cribiform Plate: located on ethmoid, allows passage
of small olfactory nerves
o Anterior Clinoid Process: end of lesser wing of
scaphoid that serves as attachment for the
Tentorium Cerebelli (dura separating the cerebral
hemispheres from the cerebellum)
o Chiasmatic Sulcus serves as border between
anterior and middle fossae
Middle cranial fossa: parts of sphenoid and temporal bones
o Sella turcica: body of sphenoid, consisting of hypophysial fossa which contains the
pituitary gland
o Posterior Clinoid Process: located on lateral end of dorsum sellae (on sella turcica)
and serve as another attachment point for the tentorium cerebelli
o Trigeminal Impression: located on the temporal bone, the location of the sensory
ganglion of the Trigeminal Nerve [V]
o Arcuate Eminence: rounded protrusion of temporal bone produced by the
underlying anterior semicircular canal of the inner ear
o Tegmen Tympani: part of temporal bone that marks the roof of the middle ear
-
Posterior cranial fossa: mostly temporal and occipital bones with small contributions from the
sphenoid and parietal bones.
o The largest and deepest of the cranial fossa
o Contains the brainstem and cerebellum
o Clivus: slope of sphenoid and occipital bones that extends upward from the foramen
magnum
o Groove for Inferior Petrosal Sinus: between basal part of occipital bone and petrous part of
temporal bone
o Groove for Sigmoid Sinus
o Jugular Tubercle: just superior to jugular foramen
o Internal Occipital Crest and Protuberance and Groove for Transverse Sinus
Internal Foramina:
Foramen
Foramen cecum
Olfactory foramina
Optic canal
Superior orbital
fissure
Foramen rotundum
Bone
Frontal
Ethmoid
Sphenoid
Sphenoid
Foramen ovale
Sphenoid
Foramen spinosum
Hiatus for greater
petrosal nerve
Hiatus for lesser
petrosal nerve
Foramen lacerum
Foramen magnum
Sphenoid
Temporal
Internal acoustic
meatus
Temporal
Sphenoid
Temporal
Sphenoid
Occipital
Hypoglossal canal
Between
Temporal and
Occipital
Occipital
Condylar canal
Occipital
Jugular foramen
Contents
Emissary veins
Olfactory nerves [I]
Optic Nerve [II] and ophthalmic artery
Oculomotor Nerve [III], Trochlear Nerve [IV], Ophthalmic nerve
[V1], Abducent Nerve [VI], and ophthalmic veins
Maxillary nerve [V2]
Mandibular nerve [V3], lesser petrosal nerve (carrying fibers of
tympanic plexus from Glossopharyngeal Nerve [IX]), accessory
middle Meningeal artery
Middle Meningeal artery and associated veins
Greater petrosal nerve (branch of Facial Nerve [VII])
Lesser petrosal nerve (carrying fibers of tympanic plexus from
Glossopharyngeal Nerve [IX])
Cartilage
Spinal cord, meninges, vertebral arteries, and the spinal roots
of the Accessory Nerve [XI]
Facial Nerve [VII], Vestibulocochlear Nerve [VIII], and the
labyrinthine artery
Sigmoid sinus forming the Internal jugular vein,
Glossopharyngeal Nerve [IX], Vagus Nerve [X], and the
Accessory Nerve [XI]
Hypoglossal Nerve [XII] leaves and Meningeal branch of
ascending pharyngeal artery (external carotid) enters
Emissary vein