Osteology + H&N Flashcards
Flat bones
Formed by intramembranous ossification.
E.g
Vomer, ethmoid, frontal, parietal, occipital, nasal, lacrimal
Irregular bones
Formed by endochondral ossification
E.g.
Inferior nasal concha, palatine, zygomatic, maxilla, mandible, ethmoid, temporal, sphenoid
Pneumatised bones
Bones with air spaces/sinuses. Reduce weight and add resonance to our voice
E.g.
Frontal, temporal, sphenoid, ethmoid
Neurocranium
Bony case of the brain meninges with roof (calvaria) and floor (cranial base)
Frontal
Parietal x2
Occipital
Sphenoid
Temporal x2
Ethmoid
Viscerocranium
Anterior part of cranium, consists of bones surrounding the oral cavity and most of orbit.
Ethmoid
Lacrimal x2
Nasal x2
Inferior nasal concha x2
Mandible
Maxilla x2
Zygomatic x2
Palatine x2
Vomer
Important features in neurocranium
External acoustic meatus
Styloid process
Mastoid process
Temporal fossa
Important features in viscerocranium
Zygomatic arch
Mandible
Infratemporal fossa
Temporal fossa
Superior and posterior borders:
Superior and inferior temporal lines
Anterior border: frontal process of the zygomatic bone and zygomatic process of frontal bone
Inferiorly: infratemporal crest of sphenoid bone (deep to zygomatic arch)
Floor: pterion
Pterion
H-shaped junction where frontal, parietal, temporal and greater wing of sphenoid bone meet.
Structurally weak, thin area.
Overlies anterior branch of middle meningeal artery
Vulnerable to injury -> blows to side of head can lead to extra dural haemmorhage
4cm superior to midpoint if zygomatic arch and 3cm posterior to frontal process of zygomatic bone.
Posterior to the pterion is the middle meningeal artery.
Nasion
Point of articulation between the 2 nasal bones and frontal bone
Inion
Central point of external occipital protuberance
Bregma
Junction of Sagittal and coronal suture
Lambda
Junction of saggital and lambdoid suture
Asterion
Junction of lambdoid, parietomastoid and occipitomastoid sutures
Glabella
Above nasion, between eyebrows
Vertex
Highest point of skull, midway across sagittal suture
Infratemporal fossa
Anterior: posterior border of maxillary sinus
Posterior: carotid sheath
Roof: greater wing of sphenoid
Laterally: condylar process of mandible and ramus
Floor: medial pterygoid
Pterygopalatine fossa
Extends from Infratemporal fossa to nasal cavity via the sphenopalatine foramen.
Contents: maxillary nerve, pterygopalatine ganglion
Sphenopalatine foramen - medial wall of pterygopalatine fossa
Pterygomaxillary fissure - leads to pterygopalatine fossa
Cribiform foramina in cribiform plate
Axons of olfactory epithelium that form olfactory nerves
Optic canals
Optic nerve and ophthalmic arteries
Superior orbital fissure
Ophthalmic nerve and veins
Oculomotor
Trochlear
Abducent
Foramen rotundum
Maxillary nerve
Foramen ovale
Mandibular nerve
Accessory meningeal artery
Foramen spinosum
Middle meningeal artery and vein
Meningeal branch on CN V3
