2 - Osteology of the skull, hyoid and cervical spine Flashcards
What is the function of the skull?
- protects brain, brainstem, cranial nerves and vasculature
- attachment for muscles (bony landmarks)
- framework for head and identity
What are the different types of bone in the skull?
- flat bones, formed by intramembranous ossification
- irregular bones, formed by endochondral ossification
- pneumatised bones, bones that have air spaces (ie sinuses), reduce the weight of the skull
What are the divisions of the skull?
- neurocranium, made up of the vault (calvaria) and the cranial base
- viscerocranium (facial), anterior part of the skull surrounding the orbit, nasal and oral cavities
- mandible
What are the 8 bones of the neurocranium?
- occipital
- parietal x2
- frontal
- temporal x2
- sphenoid
- ethmoid
What are the 14 bones of the viscerocranium?
- zygomatic x2
- maxilla x2
- palatine x2
- nasal x2
- vomer
- inferior nasal conchae x2
- lacrimal x2
- mandible
What are the main features of the norma lateralis?
Neurocranium
- external acoustic meatus
- styloid process
- mastoid process
- termporal fossa
Viscerocranium
- zygomatic arch
- mandible
- infratemporal fossa
Describe the borders of the temporal fossa.
Superior = superior temporal line
Inferior = infratemporal crest, deep to zygomatic arch
Anterior = frontal process of zygomatic bone, zygomatic process of frontal bone
Posterior = inferior temporal line
Floor = pterion
What is the correct anatomical plane of the skull?
- orbito-meatal line / Frankfort horizontal plane
- runs from the superior border of external acoustic meatus to the inferior border of the orbit
What is the asterion?
Star shaped junction of the occipital, parietal and temporal bones
What is the inion?
Most prominent protuberance of the back of the skull
What is the lambda?
- junction of the lambdoid and sagittal suture
- located at the rear of the skull
What is the vertex?
Superior and middle point of the vault of the skull
What is the bregma?
Junction of the sagittal and coronal sutures
What is the glabella?
- smooth part of bone at the most anterior protuberance of the forehead
- “hairless” in greek
What is the naison?
- junction of the nasal sutures
What is the pterion?
- H-shaped junction of sutures
- junction between the frontal, temporal (squamous), parietal and the greater wing of the sphenoid bones
- structurally thin, and overlies the anterior branch of the middle meningeal artery
- “wing” in greek