Skull Flashcards
Foramen
hole
Process
protruding structure’
Meatus
canal, tunnel, deep grove
Squamous
wide, flattened region
Fossa
Depression
Sinus
chamber
Condyle
rounded articular surface
Viscero or Splanchno
pertaining to organs
Skull is divided into two parts
- Neurocranium - 8 bones - brain/cranial vault
2. Viscerocranium - 15 bones - rest of facial area
Bone Development (prenatal)
- Enchondral - the cranial base, bones are joined by synchondroses
- Intramembranous - cranial vault and viscerocranium, bones are joined by sutures
Bone Development (postnatal)
Neurocranium bones are separated, but will “grow” closer together
Anterior and Posterior Fontanelles
Sutures
Immobile, fibrous joints connecting MOST skull bones formed by intramembranous ossification
Name sutures
Sagittal - btw right and left parietals Coronal - btw frontal and parietals Squamosal - btw temporal and parietal Lambdoidal - btw occipital and parietals Metopic - btw developing right and left frontal bones (obliterates)
Clinical Correlation - Sutures
Craniosynostosis - premature fusion of sutures
Results in various skull shapes depending on affected structures
Synchondroses
Immobile joints connecting cranial base bones formed by endochondral ossification
!. Sphenooccipital Synchondroses
Clinical Correlation - Synchondroses
Achondroplasia - type of dwarfism
Affects endochondral ossification so results in short limb bones and a shortened cranial base because of premature closure of the synchondroses
Temporal Mandibular Joint
(TMJ) - only movable joint in skull
Head of mandible (codyle) rides on articular tubercle, not against the mandibular fossa
Frontal Bone
Neurocranium
Squamosal and orbital parts
Temporal Bone
Neurocranium
Tympanic Part (technically viscerocranium)
Petro=mastoid part
Squamous part
Occipital Bone
Neurocranium
Squamous part
Condylar Part
Basilar Part
Ethmoid
Part of the neuro and viscercranium
Bregma
The point where the sagittal and coronal sutures meet
Lambda
The point at the intersection of the sagittal and lambdoidal sutures
Glabella
The most anterior midline point of the frontal boen
Nasion
The point of intersection of the nasofrontal suture and the mid-sagittal plane
Pterion
The highly variabale area that represents the intersection of the frontal, temporal, sphenoid, and parietal bones
Extremely thin and prone to fracture - damage to the middle meningial artery
Vertex
Most superior part of the cranium, typically posterior to bregma
Foramen Cecum
Nasal emissary vein to superior sagittal sinus
Foramina in Cribriform PLate
Axons of olfactory neurons from CN 1
Optic Canal
CN II
Ophthalmic arteries
Superior Orbital Fissure
Ophthalmic veins
Branches of ophthalmic CN V1
CN III, IV, VI (oculomotor, trochlear, abducens)
Sympathetic Fibers
Inferior Orbital Fissure
Maxillary nerve (CN V2) Infraorbital vessels
Supraorbital Foramen (notch)
Supraorbital nerve and vessels
Infraorbital Foramen
Infraorbital nerve and vessles (terminal branches of V2)
Foramen Rotundum
Maxillary nerve CN V2
Foramen Ovale
Mandibular nerve (V3) Accessory meningial artery
Foramen Spinosum
Middle meningeal artery and vein
Foramen Lacerum
In life this is covered by cartilage
Internal carotid artery crosses over the foramen horizontally
Sympathetic fibers and a venous plexus accompany the internal carotid artery
Carotid Canal
Internal carotid artery (with surrounding nerve plexus)
Internal Acoustic Meatus
Facial CN VII
Vestibulocochlear CN VIII
Jugular Foramen
CN IX, CN X, CN XI (glosso, vagus, accessory) Sigmoid sinus (emptying into internal jugular vein)
Condylar Canal
Emissary vein (sigmoid sinus to the vertebral veins)
Hypoglossal Canal
CN XII (hypoglossal CN)
Foramen Magnum
Medulla oblongata
Vertebral arteries and veins
Accessory CN XI
Anterior and posterior spinal arteries
Greater Palatine Foramen
Greater palatine nerve
Descending palatine vessels
Lesser Palatine Foramen
Lesser palatine nerves
Incisive Foramen
Nasopalatine nerve
Terminal branch of the descending septal artery
Stylomastoid Foramen
Facial CN VII
Mandibular Foramen/Canal
Inferior alveolar nerve and vessels
Mental Foramen
Mental nerve (terminal branch of inferior alveolar nerve) Mental vessels (terminal branches of inferior alveolar artery and vein)