Anatomy lecture on the bones of the neurocranium (osteology of neurocranium)
easy to memorize and made in a summary style
best for your study plan
detalied anatomy of each bone
with the review of what will be on exam and what is important
best for exam preperation
2. General concepts of the skull
Osteology
The skull is divided into two parts.
• The Cranium (neurocranium)
• Protects the brain
• The Facial skeleton (viscerocranium)
Viscerocranium
Neurocranium
3. General concepts of the skull
Osteology of Neurocranium
The neurocranium consists of 8 bones:
• The Frontal bone
• The parietal bones(2)
• The Occipital bone
• The Temporal bones (2)
• The Sphenoid bone
• The Ethmoid bone
4. Osteology of Neurocranium
Frontal Bone
Makes the superior part of the orbit
Features:
• coronal suture
• Glabella
• Nasion
• Supraorbital foramen
• Supraorbital ridge
• Frontal protuberance
Coronal suture
Glabella
Supraorbital foramen
Nasion
Supraorbital ridge
Apex of petrous
Frontal
protuberance
5. Osteology of Neurocranium
The parietal bones
There are two parietal bones-bilateral
Features:
• Sagittal suture
• The temporal lines
• Inferior | superior
• gives attachment to the temporal fascia
Inferior temporal line
Superior temporal line
Sagittal suture
6. Osteology of Neurocranium
The occipital bone
Features:
• Occipital condyles
• External occipital protuberance
• inion
• Superior nuchal line
• Inferior nuchal line
• External occipital crest
External
occipital
crest
Inferior nuchal line
Superior nuchal line
Occipital condyles
External occipital protuberance
Inion
7. Osteology of Neurocranium
The occipital bone
Features:
• The foramen magnum
• Hypoglossal canal
• For hypoglossal nerve
• Clivus
• Jugular foramen
• Cranial nerves IX, X, and XI and the
internal jugular vein
Clivus
Jugular foramen
Hypoglossal canal
foramen magnum
8. Osteology of Neurocranium
Ethmoid bone
Features
• Perpendicular plate
• Cribriform plate
• Crista galli
• Inferior nasal concha
Crista galli
Perpendicular
plate
Anterior view
Superior view
Cribriform plate
Inferior nasal concha
9. Osteology of Neurocranium
The temporal bone- lateral view
Features
• Mastoid process
• Attachment site for sternocleidomastoid
• Styloid process
• External acoustic meatus
• Squamous suture
• Groove for posterior deep temporal artery
• Zygomatic process of temporal bone
• Articular tubercle
Squamous
suture
Groove for
posterior deep
temporal artery
External acoustic meatus
Mastoid process
Styloid process
Zygomatic process of
temporal bone
Articular tubercle
10. Osteology of Neurocranium
The temporal bone- Medial view- left temporal bone
Features
• Tegmen tympani
• Forms Superior wall of middle ear
• Arterial groove
• Groove for sigmoid sinus
• Mastoid foramen
• Internal acoustic meatus
• Stylomastoid foramen
• facial nerve and stylomastoid
artery
Arterial groove
Mastoid foramen
Groove for sigmoid sinus
Styloid process
Apex of petrous
Internal acoustic
meatus
Zygomatic
process
Tegmen tympani
11. Osteology of Neurocranium
The sphenoid bone- structural blueprint
The sphenoid bone is made up of:
• The body
• Ala (wings)
• 2 Greater ala
• 2 lesser ala
• Pterygoid process
• Medial plate | lateral plate
Superior orbital fissure
Foramen rotundum
Foramen ovale
Foramen spinosum
Optic canal
Medial
plate
Lateral
plate
12. Osteology of Neurocranium
The sphenoid bone- wings (ALA)- details
Features:
• Foramen rotundum
• maxillary branch (V2) of the trigeminal
nerve
• Foramen ovale
• Mandibular nerve
• Foramen spinosum
• middle meningeal artery and vein
• meningeal branch of the mandibular nerve
• Foramen lacerum
• branch of the external carotid artery
• Some emissary veins
Superior orbital fissure
Foramen rotundum
Foramen ovale
Foramen spinosum
Foramen lacerum
13. Osteology of Neurocranium
The sphenoid bone- Body
• Anterior clinoid process
• Posterior clinoid process
• Dorsum salle
• Tuberculum salle
• Hypophysial fossa
• Optic canal
• For the optic nerve and ophthalmic
artery
• Optic (chiasmatic) groove
• Sella turcica
Anterior clinoid process
Tuberculum salle
Hypophysial fossa
Dorsum salle
Posterior clinoid process
groove
Optic
14. Osteology of Neurocranium
The sphenoid bone- orbital view
• Optic canal
• For the optic (II) nerve and ophthalmic
artery
• Superior orbital fissure
• Oculomotor(III) nerve
• Trochlear (IV) nerve
• Abducens (VI) nerve
• Inferior orbital fissure
• Zygomatic branch of trigeminal
nerve (cV)
Superior orbital fissure
inferior orbital fissure
Optic canal
15. Review
Foramina and nerves
• Cribriform plate of ethmoid
• I-Olfactory
• Optic canal
• II-Optic nerve
• Superior orbital fissure
• III-Oculomotor- | IV-Trochlear- |
V-Trigeminal 1 ophthalmic and VI-Abducens
• Foramen rotundum
• V-Trigeminal 2 maxillary nerve
• Foramen ovale
• V-Trigeminal 3 mandibular nerve
16. Review
Foramina and nerves
• Stylomastoid foramen
• VII-Facial
• Internal auditory meatus
• VIII-Vestibulocochlear
• Jugular foramen
• IX glossophyrengal | vagus- X
• spionoaccessory nerve
• Hypoglossal canal
• Xii
17. Review
Bones of orbit
Seven bones make up the orbit
• Frontal bone
• Sphenoid
• Ethmoid
• Zygomatic
• Maxillary
• Lacrimal
• Palatine
Frontal bone
Sphenoid
Ethmoid
Zygomatic bone
Maxillary bone
Lacrimal
Palatine bone
18. Review
Bones of nasal cavity
Roof , floor and walls are formed by 4 bones
• Ethmoid bone | Palatine bones
• Maxillary | Inferior nasal concha
• Sphenoid | nasal bones
Nasal septum is formed by :
• Perpendicular plate of ethmoid
• Vomer