skull (cranium)

Structure: In adults, the skull is a rigid structure of 6 paired & 6 unpaired bones. intracranial volume: 1400-1700 mL intracranial contents: 1) brain parenchyma 80% - including the brain (cerebrum & cerebellum), the brainstem - cranial nerves 2) cerebrospinal fluid 10% - cerebral ventricles 3) blood 10% - associated arteries & veins Paired bones: 1) inferior nasal concha 2) lacrimal bone 3) nasal bone 4) palatine bone 5) temporal bone 6) zygomatic bone Unpaired bones: 1) ethmoid bone 2) frontal bone 3) occipital bone 4) sphenoid bone 5) maxilla 6) vomer - skull is thickened at the a) glabella b) external occipital protuberance c) mastoid processes - skull vault is composed of cancellous bone (diploe) sandwiched between the lamina externa (1.5 mm), & the lamina interna (0.5 mm) - diploe does not form where the skull is covered with muscles leaving the vault thin & prone to skull fracture.

Related

anterior cranial fossa middle cranial fossa posterior cranial fossa (cerebellar fossa) skull fracture (cranial fracture)

Specific

arcuate eminence carotid groove; cavernous groove; carotid sulcus; cavernous sulcus epicranium incisive/incisor/Stensen foramen inferior articular facet of atlas; inferior articular (pit/surface) of atlas internal occipital protuberance lambda lateral mass of atlas nasal spine of frontal bone parietal eminence/tubercle parietal foramen posterior nasal spine of horizontal plate of palatine bone (posterior palatine spine) skull at birth skull in childhood skull in infancy sutural bone

References

Stedman's Medical Dictionary 27th ed, Williams & Wilkins, Baltimore, 1999

Components

alveolar foramina of maxilla diploic vein (Breschet vein, Dupuytren canal) ethmoid bone fontanelle frontal bone lacrimal bone nasal bone occipital bone palatine bone parietal bone postglenoid foramen pterygomaxillary fissure pyramidal process of the palatine bone sphenoid bone sphenopalatine foramen suprameatal spine (Henle spine) temporal bone vomer zygomatic bone; zygoma; malar bone