Assoc. Prof. Květuše Lovásová, M.V.D., PhD. Skull basic structures Skull consists of two groups of bones: neurocranium (bones forming the brain box) splanchnocranium (bones forming the facial skeleton) Neurocranium Frontal bone Squamous part: external surface frontal tuber, glabella, superciliary arch, supraorbital margin, supraorbital notch (supraorbital foramen), frontal notch (frontal foramen), zygomatic process, temporal line Frontal sinus - septum of frontal sinuses internal surface groove for superior sagittal sinus, frontal crest, foramen cecum Orbital part (paired): Fossa for lacrimal gland (lacrimal fossa), trochlear spine, trochlear fovea, ethmoidal notch, impressions of cerebral gyri (digitate impressions) Nasal part: nasal spine Anterior/posterior ethmoidal foramen (between orbital part of frontal bone and orbital plate of ethmoidal labyrinth of ethmoid) Ethmoidal bone (Ethmoid) Cribriform plate: crista galli - ala of crista galli (paired), cribriform foramina Perpendicular plate Ethmoidal labyrinth (paired): anterior/middle/posterior ethmoidal cells, ethmoidal bulla, orbital plate, supreme/superior nasal concha, middle nasal concha - uncinate process Sphenoidal bone (Sphenoid) Body of sphenoid:
sella turcica (Turkish saddle), hypophyseal fossa, dorsum sellae, posterior clinoid process, prechiasmatic sulcus, carotid sulcus, sphenoidal lingula, sphenoidal rostrum, sphenoidal crest, sphenoidal sinus - septum of sphenoidal sinuses, sphenoidal conchae/apertures Lesser wing (paired): jugum sphenoidale (sphenoidal yoke), anterior clinoid process, optic canal Superior orbital fissure Greater wing (paired): cerebral surface impressions of cerebral gyri (digitate impressions), cerebral yokes, foramen rotundum/ovale/spinosum temporal surface infratemporal crest infratemporal surface foramen ovale/spinosum, spine of sphenoid, sulcus of auditory tube orbital surface maxillary surface foramen rotundum Pterygoid process (paired): lateral plate pterygospinous process Pterygoid notch - pterygoid fossa, scaphoid fossa medial plate pterygoid hamulus pterygoid canal (Vidian) Foramen lacerum (after maceration of skull) Temporal bone (paired) Petrous part: apex of petrous part anterior surface trigeminal impression, groove for greater/lesser petrosal nerve, hiatus for greater/lesser petrosal nerve, arcuate eminence, tegmen tympani Superior border - groove for superior petrosal sinus posterior surface internal acoustic opening - internal acoustic meatus, subarcuate fossa, external opening of vestibular aquaeduct (vestibular canaliculus), posterior border - jugular notch, groove for inferior petrosal/sigmoid sinus, mastoid foramen
Jugular foramen (partially bounded by jugular notch) inferior surface musculotubal canal - septum of musculotubal canal canal for tensor tympani muscle, canal for auditory tube, carotid canal - caroticotympanic canaliculi, jugular fossa - mastoid canaliculus, external opening of cochlear canaliculus, petrosal fossula - tympanic canaliculus, styloid process, stylomastoid foramen, mastoid process, mastoid notch, occipital groove, mastoid foramen Tympanic part: external acoustic opening - external acoustic meatus, tympanic sulcus Tympanomastoid/tympanosquamous/petrotympanic/petrosquamous fissure Squamous part: zygomatic process, mandibular fossa - articular tubercle, groove for middle temporal artery Parietal bone (paired) frontal/occipital/sphenoid/mastoid angle external surface parietal tuber (parietal eminence), superior/inferior temporal line, parietal foramen internal surface groove for superior sagittal sinus, parietal foramen, groove for middle meningeal artery frontal/occipital/sagittal/squamous border Occipital bone Basilar part: pharyngeal tubercle, clivus, groove for inferior petrosal sinus Lateral part (paired): occipital condyle, hypoglossal canal, jugular tubercle, condylar fossa - condylar canal, jugular notch - intrajugular process, jugular process Jugular foramen (partially bounded by jugular notch) Squamous part: external surface external occipital protuberance, external occipital crest, supreme (highest)/superior/inferior nuchal line internal surface internal occipital protuberance, cruciform eminence, internal occipital crest, groove for superior sagittal sinus, groove for transverse/sigmoid sinus, cerebral/cerebellar fossa
Foramen magnum Calvaria (cranial vault) Frontal bone (partially), parietal bones, occipital bone (partially) Splanchnocranium Mandible Body of mandible: alveolar part, alveolar arch, juga alveolaria (alveolar yokes), dental alveoli - interradicular septa, interalveolar septa, base of mandible, mental protuberance - mental tubercle, mental foramen, oblique line, mental spine, digastric fossa, sublingual/submandibular fossa, mylohyoid line Angle of mandible masseteric/pterygoid tuberosity Ramus of mandible (paired): coronoid process - temporal crest, mandibular notch, condylar process head of mandible - neck of mandible - pterygoid fovea, mandibular foramen - mandibular canal, lingula of mandible, mylohyoid groove Maxilla (paired) Body of maxilla: orbital surface infraorbital groove, infraorbital canal, infraorbital margin anterior surface infraorbital foramen, canine fossa, anterior nasal spine, nasal notch infratemporal surface maxillary tuberosity - alveolar foramina - alveolar canals nasal surface lacrimal groove, conchal crest, lacrimal margin, greater palatine groove, maxillary hiatus maxillary sinus: zygomatic/frontal/ /palatine/alveolar recess Processes of maxilla: frontal process anterior lacrimal crest, lacrimal groove, ethmoidal crest alveolar process alveolar arch, juga alveolaria (alveolar yokes), dental alveoli - interradicular septa, interalveolar septa palatine process incisive foramen - incisive canal, incisive suture, median palatine suture - palatine torus, transverse palatine suture, palatine grooves and spines, nasal crest
zygomatic process Piriform aperture: bodies and frontal processes of maxillae and nasal bones Zygomatic bone (paired) orbital surface zygomaticoorbital foramen lateral surface zygomaticofacial foramen temporal surface zygomaticotemporal foramen temporal/frontal process Zygomatic arch: zygomatic process of temporal bone and temporal process of zygomatic bone Palatine bone (paired) Horizontal plate: nasal/palatine surface, nasal/palatine crest, posterior nasal spine Perpendicular plate: maxillary surface, nasal surface - conchal/ethmoidal crest, greater palatine groove, pyramidal process - lesser palatine foramina orbital process sphenopalatine notch - sphenopalatine foramen sphenoidal process Greater palatine foramen - greater palatine canal bounded by greater palatine groove of body of maxilla and perpendicular plate of palatine bone Inferior nasal concha (paired) Lacrimal bone (paired) posterior lacrimal crest, lacrimal groove, fossa for lacrimal sac Nasal bone (paired) Vomer Auditory ossicles: malleus (hammer), incus (anvil), stapes (stirrup) part of the middle ear (paired) Hyoid bone: body, greater/lesser horn in the anterior region of the neck On the internal cranial base: Anterior cranial fossa Middle cranial fossa Skull cavities
Posterior cranial fossa Anterior view of the skull: Osseous (bony) nasal cavity Orbit Lateral view of the skull: Temporal fossa Infratemporal fossa Pterygopalatine fossa