Presentation on theme: "The Skull & Cranial Cavity"— Presentation transcript:
1The Skull & Cranial Cavity BrainMeningesCranial nervesArterial supplyVenous sinusesDr Frank CT Voon30 March 2009
2The Neurocranium Frontal Parietal Occipital Ethmoid Temporal Sphenoid Tip: PETS OF or FPOETS.
3The 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.
4The NeurocraniumThe 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.
5The NeurocraniumIt 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.
6Intramembranous 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.
7Endochondral 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.
8The Brain and spinal cord Cerebral hemispheresDiencephalonMidbrainPons and cerebellumMedulla oblongataSpinal cord