1. The Skull & Cranial Cavity
Brain
Meninges
Cranial nerves
Arterial supply
Venous sinuses
Dr Frank CT Voon
30 March 2009

2. The Neurocranium Frontal Parietal Occipital Ethmoid Temporal Sphenoid
Tip: PETS OF or FPOETS.

3. The Cranium The cranium (skull) is the skeleton of the head.
It consists of a neurocranium and a viscerocranium.
The neurocranium is also known as the cranial vault.
The viscerocranium is also known as the facial skeleton.

4. The Neurocranium
The neurocranium (cranial vault) has a roof and a floor.
The roof (calvaria or skull cap) is shaped like a dome.
The basicranium (cranial base) forms the floor.
It encloses the cranial cavity.

5. The Neurocranium
It is formed by 8 bones, the frontal, parietal, occipital, temporal, ethmoidal and sphenoidal bones.
The frontal, occipital, ethmoidal and sphenoidal bones are single and thus are in the midline.
The parietal and temporal bones are bilateral and hence are paired.
The fibrous joints between the bones are known as sutures.

6. Intramembranous ossification
The frontal, parietal and temporal bones are formed by intramembranous ossification and are known as flat bones.
Do note that these flat bones forming the calvaria are actually curved, with a convex external surface and a concave internal surface.

7. Endochondral ossification
The sphenoid, ethmoid and temporal bones are mainly formed by endochondral ossification and are known as irregular bones.
These bones form the cranial base.
The ethmoid is a part of both the neurocranium and viscerocranium.

8. The Brain and spinal cord
Cerebral hemispheres
Diencephalon
Midbrain
Pons and cerebellum
Medulla oblongata
Spinal cord

9. Sensory cortex
Motor cortex
Parietal lobe
Frontal lobe
Occipital lobe
Temporal lobe

10. The Cranial nerves Olfactory Optic Oculomotor Trochlear Trigeminal
Abducens
Facial
Vestibulocochlear
Glossopharyngeal
Vagus
Accessory
Hypoglossal

11. The 12 cranial nerves

12. Foramina Structures that pass through the foramina Cranial nerves
Arteries - Internal carotid and vertebral
Veins – sigmoid sinus and beginning of internal jugular vein
Spinal cord – Foramen magnum

13. Circle of Willis Anterior communicating artery
Anterior cerebral artery
Perforating arteries
Internal carotid artery
Ophthalmic artery
Middle cerebral artery
Anterior choroidal artery
Posterior communicating artery
Posterior cerebral artery
Superior cerebellar artery
Basilar artery
Pontine arteries
Anterior inferior cerebellar artery
Vertebral artery

14. The flow of CSF

15. Superior sagittal sinus
Arachnoid granulations
Emissary veins
Skin
Close tissue
Aponeurosis
Loose tissue
Periosteum
Outer table
Diploe
Inner table
Dura mater
Endosteum
Arachnoid mater
Subdural space
Pia mater
Gray matter
Subarachnoid
space
White matter
Falx cerebri
Cerebrospinal fluid

16. Superior Sagittal Sinus
Venous sinuses
Superior Sagittal Sinus
Inferior Sagittal Sinus
Confluence
Straight Sinus
Internal occipital protruberance
Superior Petrosal Sinus
Occipital Sinus
Sigmoid
Cavernous Sinus
Sinus
Inferior
Petrosal
Sinus
Transverse Sinus
Jugular foramen
Internal Jugular Vein

17. The Scalp and Cranial Cavity
Skin
Close subcutaneous tissue
Aponeurosis
Loose areolar tissue
Periosteum
Outer table
Diploe
Inner table
Endosteum
Endosteal layer of dura mater
Menigeal layer of dura mater
Arachnoid mater
Pia mater
Brain
Grey matter
White matter
Ventricles

18. Meninges and spaces Dura mater Arachnoid mater Pia mater
Extradural space
Dura mater
Subdural space
Arachnoid mater
Subarachnoid space
Pia mater
Gray matter
White matter
Ventricles