Important!
- Although at least the 95% of the structeres of the scull –including the neurocranium and the facial skeleton – is listed here, memorizing these pages only does not guarantee the succesfull passing of the midterm test or the semifinal exam.
- The handout has not been supervised, and I can not guarantee, that these pages are absolutely free from mistakes. If you find any, please, report to me!
Skull - 1.The neurocranium
Frontal bone [os frontale]
- squamous part [pars squamosa, squamma frontalis]
External surface
- frontal tuber or eminence [tuber frontale]
- superciliary arch [arcus superciliaris]
- glabella
- supraorbital margin [margo supraorbitalis]
- supraorbital foramen or notch [foramen supraorbitale seu incisura supraorbitalis]
- frontal notch or foramen [incisura frontalis seu foramen frontale]
- zygomatic process [processus zygomaticus]
Internal surface
- frontal crest [crista frontalis]
- foramen cecum
- orbital parts [partes orbitales]
Cerebral surface
- impressions for cerebral gyri [impressiones digitatae seu impressiones gyrorum]or brain markings
Orbital surface
- fossa for lacrimal gland [fossa glandulae lacrimalis]
- trochlear pit or fossa [fovea seu fossa trochlearis]
- trochlear spine [spina trochlearis]
- nasal part [pars nasalis]
Can not be identified on the whole skull, contributes to the roof of the nasal cavity.
Parietal bone [os parietale]
Internal surface of calvaria (skull cap)
- groove for superior sagittal sinus [sulcus sinus sagittalis superioris]
- granular pits [foveolae granulares]
- groove for middle meningeal artery or simply arterial groove [sulcus arteriae meningeae mediaeseu sulci arteriosi]
External surface of calvaria
- superior and inferior temporal lines [linea temporalis superior et inferior]
- parietal tuber or eminence [tuber parietale]
Sphenoid bone [os sphenoidale]
(The sphenoid bone is discussed with the bones of the neurocranium, but also contributes to the facial skeleton!)
1. body of sphenoid [corpus ossis sphenoidalis](a cube with six sides!)
a) anterior surface:contributes to the posterior-superior wall of the nasal cavity
- sphenoidal crest [crista sphenoidalis]
- aperture of sphenoidal sinuses [apertura sinus sphenoidalis]
b) inferior surface: forms the roof of the choana
c) posterior surface:fused with the basilar part of occipital bone (basiocciput)
d) lateral surface:carotid groove [sulcus caroticus]
e) superior surface:this is the most important!!!
- spenoidal yoke [jugum sphenoidale]
- prechiasmatic groove [sulcusprechiasmaticus]
- tubercle of saddle [tuberculum sellae]
- hypophysial or pituitary fossa or Turkish saddle [fossa hypophysialisseu sella turcica]
- dorsum sellae
- middle and posterior clinoid process [processus clinoideus medius et posterior]
- lesser wing [ala minor]
- optic canal [canalis opticus]
- anterior clinoid process [processus clinoideus anterior]
- greater wing [ala major]
a) cerebral surface
- superior orbital fissure [fissura orbitalis superior]
- foramen rotundum
- foramen ovale
- foramen spinosum
- (foramen lacerum: also bounded by the petrous part of temporal bone and the basilar part of the occipital bone)
b) temporal surface
c)infratemporal surface
b) and c) are separated by the infratemporal crest [crista infratemporalis]
d) orbital surface:cotributes to the lateral wall of the orbit
e)maxillary surface: forms the posterior boundary of the pterygopalatine fossa
- pterygoid process [processus pterygoideus]
- medial and lateral plates of the pterygoid process [lamina medialis et lateralis processus pterygoidei]
- pterygoid fossa [fossa pterygoidea]
- pterygoid hook [hamulus pterygoideus]
- scaphoid fossa [fossa scaphoidea]
- pterygoid canal [canalis pterygoideus]
Temporal bone [os temporale]
- squamous part [pars squamosa]
- mandibular fossa [fossa mandibularis]
- articular tubercle [tuberculum articulare]
- zygomatic process → zygomatic arch [processus zygomaticus → arcus zygomaticus]
- petrous part [pars petrosa]
- petrous crest or ridge [margo superior partis petrosae]
a)anterior or cerebral surface
- trigeminal impression [impressio trigemini]
- arcuate eminence [eminentia arcuata]
- hiatus for the canal of greater and lesser petrosal nerves [hiatus canalis nervi petrosi majoris et minoris]
- grooves for greater and lesser petrosal nerves [hiatus canalis nervi petrosi majoris et minoris]
- (foramen lacerum: also bounded by the greater wing of the sphenoid bone and the basilar part of the occipital bone)
b)posterior or cerebellar surface
- groove for superior and inferior petrosal sinuses [sulcus sinus petrosi superioris et inferioris]
- internal acoustic poreand meatus[porus et meatus acusticus internus]
- external opening of the vestibular aqueduct [apertura externa aquaeductus vestibuli]
c)inferior or external surface
- sheath of styloid process [vagina processus styloidei]
- stylomastoid foramen [foramen stylomastoideum]
- jugular fossa → jugular foramen [fossa jugularis → foramen jugulare]
- mastoid canaliculus [canaliculus mastoideus]
- carotid canal [canalis caroticus]
- caroticotympanic canaliculi [canaliculi caroticotympanici]
- petrosal fossula [fossula petrosa]
tympanic canaliculus [canaliculus tympanicus]
inferior opening of the cochlear aqueduct [apertura inferior seu externa aqueductus cochleae]
- musculotubal canal [canalis musculotubarius] – semicanal for the tensor tympani muscle and semicanal for the auditory tube
3. mastoid part [pars mastoidea]
- mastoid notch [incisura mastoidea]
- mastoid foramen [foramen mastoideum]
- groove for occipital artery [sulcus arteriae occipitalis]
- groove for sigmoid sinus [sulcus sinus sigmoidei]
4. tympanic part[pars tympanica]
- externali acoustic poreand meatus [porus et meatus acusticus externus]
- hyoid part [pars hyoidea]
- styloid process [processus stylodeus]
Structures bounded by the parts of the temporal bone: petrotympanic or Glaserian fissure [fissura petrotympanica], tegmental crest [crista tegmentalis], petrosqamous fissure [fissura petrosquamosa],tympanomastoid fissure [fissura tympanomastoidea].
Occipital bone [os occipitale]
- squamous part [pars squamosa]
external surface
- external occipital protuberance [protuberantia occipitalis externa]
- highest, superior and inferior nuchal lines [linea nuchalis suprema, superior et inferior]
- external occipital crest [crista occipitalis externa]
internal surface
- groove for superior sagittal sinus [sulcus sinus sagittalis superioris]
- internal occipital crest [crista occipitalis interna]
- internal occipital protuberance [protuberantia occipitalis interna]
- groove for transverse sinus [sulcus sinus transversi]
- cruciform eminence [eminentia crutiformis]
- cerebral fossa [fossa cerebralis]
- cerebellar fossa [fossa cerebellaris]
- lateral parts [partes laterales]
external surface
- occipital condyle [condylus occipitalis]
- condylar fossa [fossa condylaris]
- condylar canal [canalis condylaris]
internal surface
- jugular tubercle [tuberculum jugulare]
- jugular notch [incisura jugularis]
- jugular foramen [foramen jugulare]
- intrajugular process [processus intrajugularis]
- hypoglossal canal [canalis hypoglossi]
- groove for sigmoid sinus [sulcus sinus sigmoidei]
- basilar part [pars basilaris]
- groove for inferior petrosal sinus [sulcus sinus petrosi inferioris]
- pharingeal tubercle [tuberculum pharingeum]
great foramen [foramen magnum]: surrounded by all the three parts of the occipital bone.
2. The facial skeleton
Etmoid bone [os etmoidale]
Etmoid is an unpaired bone located at the roof of the nose between the two orbits. It is constituted mainly by paper-thin, lightweight bony plates which enclose several cavities, termed etmoidal sinuses.
1. perpendicular plate [lamina perpendicularis]
The vertical plate of the bone in the midline, which forms the superior-anterior part of the bony nasal septum [septum nasi osseum]
2. cribriform plate with cribriform foramina [lamina cribrosa et foramina cribrosa]
The horizontal plate of the bone which contributs to the roof of the nasal cavity.
3. ethmoidal labyrinth with etmoidal cells [labirynthus ethmoidalis et cellulae ethmoidales]
A mass of air cells with thin bony walls forming a part of the lateral wall of the nasal cavity. The cells are arranged in three groups, anterior, middle, and posterior, and are closed laterally by the orbital or paper plate [lamina orbitalis seu papyracea] which contributes to the medial wall of the orbit.
4. superior and middle nasal concha or turbinate [concha nasalis superior et medius]
Two curved, shell-like plates which arise from the medial wall of the ethmoidal labyrinth (note: it is the lateral wall of the nasal cavity!) and project into the nasal cavity separating the sphenoethmoidal recess [recessus sphenoethmoidalis], the superior and the middle meatus [meatus nasi superior et medius]
- ethmoidal bulla [bulla ethmoidalis]
- ucinate process [processus uncinatus]
- semilunar hiatus [hiatus semilunaris]
Semilunar hiatus is a deep, narrow openingon the lateral wall of the middle meatus of the nasal cavity bounded superior-posteriorly by the etmoidal bulla and anterior-inferiorly by the uncinate process.(These structures are hidden by the middle nasal concha and become visible following the removal of this “shielding”.)
Zygomatic bone or cheekbone[os zygomaticum]
frontal and temporal processes [processus frontalis et temporalis]
orbital surface: contributes to the anterolateral wall of the orbit.
- zygomaticoorbital foramen [foramen zygomaticoorbitale]
temporal surface: is directed posteriorly and medially, the upper part forms the anterior boundary of the temporal and the lower part of the infratemporal fossa, respectively.
- zygomaticotemporal foramen [foramen zygomatycotemporale]
malar or lateral surface:
- zygomaticofacial foramen [foramen zygomaticofaciale]
- zygomatic canal [canalis zygomaticus]:
An Y-shaped passage through the zygomatic bone which commences with the zygomaticoorbital foramen and terminates on the temporal and malar surfaces as the zygomaticotemporal and zygomaticofacial foramen.
Maxilla
1.the body of maxilla [corpus maxillae]
The body of the maxilla is somewhat pyramidal in shape (with four triangle-shaped sides) , and contains a large cavity, the maxillary sinus.
a)anterior surface
- infraorbital margin [margo infraorbitalis]
- infraorbital foramen [foramen infraorbitale]
- canine fossa [fossa canina]
b)orbital surface
Constitutes the largest (anterior) portion of the floor of the orbit, medially articulates with the lacrimal bone and the orbital plate of etmoid, posteriorly joins the orbital process of palatine, laterally bounds the inferior orbital fissure.
- infraorbital groove → infraorbital canal →infraorbital foramen
↓ ↓
alveolar canals
(transmit nerves and vessels to anterior maxillary teeth)
c)infratemporal surface
- pterygomaxillar fissure [fissura pterygomaxillaris]
- maxillar tuber [tuber maxillae]
- alveolar foramina → alveolar canals
(transmit nerves and vessels to posterior maxillary teeth)
d)nasal surface
This surface is rather conceptual as its greater portion is occupied by the maxillary hiatus, the aperture of the maxillary sinus.
- nasolacrimal groove [sulcus nasolacrimalis]
2. frontal process
Constitutes the most anterior portion of the medial wall of the orbit.
- anterior lacrimal crest [crista lacrimalis posterior]
3.zygomatic process
Not a real process, articulates with the zygomatic bone.
- alveolar process
Processes of the two sides fuse into the alveolar arch which contains the tooth sockets.
- anterior nasal spine [spina nasalis anterior]
- tooth socket[alveolus dentalis]
- alveolar yokes [juga alveolaria]
- interalveolar septum [septum interalveolare]
- interradicular septum [septum interradiculare]
5.palatine process
With the horizontal plate of the palatine bone, form the bony palate.
- median and transverse palatine suture [sutura palatina mediana et transversa]
- nasal crest [crista nasalis]
- incisive canal and foramen [foramen incisivum et canalis incisivus]
An Y-shaped passage which connects the two halves of the nasal cavity with the bony palate.
Lacrimal bone [os lacrimale]
The lacrimal bone, the smallest and most fragile bone of the face, is situated at the front part of the medial wall of the orbit.
- posterior lacrimal crest [crista lacrimalis posterior]
- fossa for lacrimal sac [fossa sacci lacrimalis]
- nasolacrimal canal [canalis nasolacrimalis]
Nasal bone [os nasale]
The nasal bones are two small bones placed side by side at the middle and upper part of the face, and form, by their junction, "the bridge" of the nose.
Vomer
The vomer is one of the unpaired facial bones of the skull. It is located in the midsagittal line, and together with the perpendicular plate of ethmoid forms the bony nasal septum.
- wing of vomer [ala vomeris]
Inferior nasal concha [concha nasalis inferior]
- lacrimal process [processus lacrimalis]]
- ethmoidal process [processus ethmoidalis]
Palatine bone [os palatinum]
The palatine bone somewhat resembles the letter L, and consists of a horizontal and a perpendicular plate.
1.perpendicular plate
- orbital process [processus orbitalis]
- spenoidal process [processus sphenoidalis]
- pyramidal process [processus pyramidalis]]
- sphenopalatine notch [incisura spenopalatina]
2. horizontal plate
- greater palatine foramen and canal [foramen et canalis palatinus major]
- lesser palatine foramina and canals [foramina et canales palatini minores]]
- posterior nasal spine [spina nasalis posterior]
- median and transverse palatine suture [sutura palatina mediana et transversa]
Mandible
1.Ramus of mandible
- coronoid process [processus coronoideus]
- oblique line [linea obliqua]
- mandibular notch [incisura mandibularis]
- condylar process [processus condylaris]
- head with articular surface (condyle of mandible) [caput et condylus mandibulae]
- neck [collum mandibulae]
- pterygoid pit [fovea pterygoidea]
- mandibular foramen → mandibular canal [foramen et canalis mandibulae]
- lingula of mandible [lingula mandibulae]
2. Body of mandible
- angle [angulus]
- pterygoid tuberosity (inside) [tuberositas pterygoidea]]
- masseteric tuberosity (outside) [tuberositas masseterica]
- mylohyoid groove [sulcus mylohyoideus]
- mylohyoid line [linea mylohyoidea]
- submandibular fossa [fossa submandibularis]
- sublingual fossa [fossa sublingualis]
- digastric fossa [fossa digastrica]
- mental spine [spina mentalis]
- mental protuberance [protuberancia mentalis]
- mental foramen [foramen mentale]
- alveolar process [processus alveolaris]
- tooth sockets (alveoli) [alveoli dentales]
- interalveolar and interradicular septa [septa interalveolaria et interradicularia]
- alveolar yokes [juga alveolaria]
- retromolar triangle [trigonum retromolare]
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