Bones of the skull: I. Bones of the neurocranium: 1. Parietal bone (os parietale) 2. Tempotal bone (os temporale) 3. Occipital bone (os occipitale) 4. Sphenoidal bone (os sphenoidale) 5. Frontal bone (os frontale) Parietal bone: Sutures: 1. Lambdoid suture: between occipital squama and parietal bones. 2. Coronal suture: between parietal bones and frontal bone. 3. Squamous suture: between squamous part of the temporal bone and the parietal bone on both sides. 4. Sagittal suture: between parietal bones. Items of the internal (cranial) surface: Sulcus for superior sagittal sinus (Sulcus sinus sagittalis superioris): It contains the superior sagittal sinus (venous sinus) and continues on the frontal and occipital bones. Foveolae granulares: irregular depressions along the sulcus for superior sagittal sinus containing the arachnoid granulations (small processes of the arachnoid involved in the drainage of the cerebrospinal fluid.) Sulci arteriosi: they contain branches of the meningeal arteries and continue on the frontal and temporal bones. Item of the external surface: Tuber parietale: ossification centre in the embryonic life 1 Temporal bone: 1. 2. 3. 4. 5. Includes the bony parts of the external, middle and internal ears. Forms the articular cavity of the temporomandibular joint. Takes part in the formation of the zygomatic arch. Takes part in the formation of the base and the lateral wall of the skull. Contains the carotid canal and facial canal. It developes from 4 parts: 1. Squamous part 2. Petrous part (pyramid and mastoid part) 3. Tympanic part 4. Hyoid part ( derives from the post. part of the II. pharyngeal arch) Items of the pars squamosa: Mandibular fossa (Fossa mandibularis): articular cavity of the temporomandibular joint Articular tubercle (Tuberculum articulare): an elevation anterior to mandibular fossa which is covered by cartilage.It plays a role in the movements of temporomandibular joint. Zygomatic process: it joins the zygomatic bone to form the zygomatic arch. Parts of the pars petrosa: A. Pyramid B. Pars mastoidea A. Parts of the Pyramid: 1. Base: it takes part in the formation of the lateral wall of the skull and gives rise to the pars mastoidea. 2. Apex: takes part in the formation of the base of the skull extending to the body of the sphenoid bone. 3. Anterior surface: Trigeminal impression (Meckel’s fossa): located at the apex and contains the Gasserian ganglion (trigeminal ganglion) enclosed in a dural sac. Hiatus of the canal of the greater petrosal nerve (hiatus canalis nervi petrosi majoris): opening of the canal of the greater petrosal nerve. The continuation of the canal is the sulcus of the greater petrosal nerve on the anterior surface of the petrous bone.The greater petrosal nerve is the first branch of the facial nerve that carries autonomic, preganglionic fibers to the pterygopalatine ganglion. Hiatus of the canal of the lesser petrosal nerve (hiatus canalis nervi petrosi minoris): opening of the canal of the lesser petrosal nerve ( from 2 4. glossopharyngeal nerve). Lesser petrosal nerve carries preganglionic fibers to the otic ganglion. Sulcus of the greater petrosal nerve (sulcus nervi petrosi majoris): it extends to the foramen lacerum behind and parallel to the sulcus of the lesser petrosal nerve. Sulcus of the lesser petrosal nerve: it extends to the foramen lacerum, where the lesser petrosal nerve leaves the cranial cavity. Sphenopetrosal synchondrosis: Fibrocartilaginous joint between the greater wing of the spenoid bone and the petrous bone. Foramen lacerum: irregular opening at the apex of the petrous bone filled with fibrous cartilage through which the greater and lesser petrosal nerves leave the cranial cavity.A short portion of the internal carotid artery lies on the cartilage filling the foramen lacerum. Eminentia arcuata: small, round elevation formed by one of the semicircular canals in the internal ear. Tegmen tympani: roof of the tympanic cavity, found anterolaterally to the arcuate eminence. Posterior surface: Porus acousticus internus: opening of the meatus acusticus internus to the posterior cranial fossa Internal acustic meatus (meatus acousticus internus): connects the posterior cranial fossa with the internal ear. It contains: Vestibulocochlear nerve Facial nerve (its canal originates from the fundus of the meatus) Labyrinthine artery ( branch of the basilar artery supplying the internal ear) Vestibular ganglion of Scarpa (sensory ganglion of the vestibular nerve) External aperture of the vestibular aqueduct (apertura externa aqueductus vestibuli): Contains perilymph and the endolymphatic duct. It is found laterally to the porus acousticus internus near to the arcuate eminence. Arises from the vestibule of the internal ear and opens into the posterior cranial fossa. It is involved in the drainage of the excess of the perilymph and endolymph from the internal ear probably to the cerebrospinal circulation or the venous circulation. 3 Sulcus of the superior petrosal sinus: Lies along the superior margin of petrous bone containing the superior petrous sinus. Sulcus of the inferior petrosal sinus: It lies over the petrooccipital synchondrosis and contains the inferior petrosal sinus. 5. Inferior surface: Styloid process / Processus styloideus (pars hyoidea): Long slender process between the petrous and tympanic parts for the attachment of muscles and ligaments. Stylomastoid foramen (Foramen stylomastoideum): External opening of the facial canal between the styloid and mastoid processes through which the facial nerve leaves the skull. Jugular fossa (Fossa jugularis): it’s found beside the jugular foramen containing the upper bulb of the internal jugular vein. Jugular notch (incisura jugularis): It is divided into two parts by the intrajugular process. It forms the number „8”-shaped jugular foramen with the jugular notch of the occipital bone. The anteromedial smaller part of the jugular foramen contains the IX., X., XI. cranial nerves, and the superior sensory ganglia of the glossopharyngeal and vagus nerves. The posterolateral larger part of the foramen contains the internal jugular vein. Carotid canal (canalis caroticus): Bony canal of the internal carotid artery. Its external opening is located anteromedially to the jugular fossa. Gives rise to the caroticotympanic canals which open into the tympanic cavity. Fossula petrosa: Small depression between the jugular fossa and opening of the carotid canal containing the petrous ganglion (inferior sensory ganglion of the IX. cranial nerve) and the external opening of the tympanic canaliculus (tympanic nerve from IX. nerve) The external aperture of the cochlear aequeduct is located between fossula petrosa and jugular fossa. The cochlear duct drains perilymph from the internal ear. B.Pars mastoidea: Mastoid process (processus mastoideus): contains the mastoid air-cells (cellulae mastoideae) communicating with the tympanic cavity. 4 Sulcus for the sigmoid sinus (Sulcus sinus sigmoidei): ends at the jugular foramen where the internal jugular vein starts as direct continuation of the sigmoid sinus. Pars tympanica: Meatus acousticus externus: bony part of the ext. acoustic meatus (it joins the cartilaginous part of the ext. acoustic meatus, its internal opening is closed by the tympanic membrane) Porus acousticus externus ( external opening of the bony external acoustic meatus) Petrotympanic fissure (Glasers’s fissure) Deep fissure between the petrous and tympanic parts leading into the tympanic cavity. It contains the chorda tympani (facial nerve) leaving the tympanic cavity and entering the infratemporal fossa. Anterior to the petrotympanic fissure the petrosquamous fissure is found that leads into the cranial cavity. Canals of the temporal bone: Facial canal (canalis facialis): it has 3 portions: 1. portion: perpendicular to the axis of the pyramid 2. portion: parallel to the axis of the pyramid 3. portion: perpendicular to the first two portions, runs vertically and ends with the stylomastoid foramen. At the junction of the 1. and 2. portions there is the external geniculum of the facial nerve containing the geniculate ganglion and the origination of the greater petrosal nerve from the facial nerve. From the third portion arises the canal of the chorda tympani. Carotid canal (canalis caroticus): contains the internal carotid artery and the aortic sympathetic nerve plexus Caroticotympanic canaliculi (canaliculi caroticotympanici): contains small branches of the int. carotid a. and sympathetic nerves to supply the tympanic cavity. Tympanic canaliculus (canaliculus tympanicus): contains the tympanic nerve (first branch of the glossopharyngeal nerve and its continuation is the lesser petrosal nerve). It opens into the tympanic cavity. Canal of the greater petrosal nerve (canalis nervi petrosi majoris): arises from the facial canal. Canal of the lesser petrosal nerve (canalis nervi petrosi minoris): arises from the tympanic cavity. 5 Canaliculus of the chorda tympani (canaliculus chordae tympani): arises from the facial canal and opens into the tympanic cavity through its posterior wall. Canalis musculotubarius: - Opens into the tympanic cavity through its anterior wall - Contains the tensor tympani muscle in its upper part, and the bony auditory tube in its lower part. - Its anteromedial continuation is the sulcus of the auditory tube containing the cartilaginous part of the tube. 6 Occipital bone (os occipitale): unpaired bone that is partly involved in the formation of the base of the skull.Its parts surround the foramen magnum. Foramen magnum: contains the junction of the spinal cord and with the medulla oblongata, vertebral arteries, spinal arteries, vertebral venous plexus, spinal root of the accessory nerve. Parts: Pars basilaris: Clivus: the brainstem rests on it. Pharyngeal tubercle (Tuberculum pharyngeum): point of the superior constrictor pharyngis muscle attachment. Sulcus for the inferior petrosal sinus (Sulcus sinus petrosi inferioris): it rests on the petrooccipital synchondrosis. Sphenooccipital synchondrosis (Synchondrosis sphenooccipitalis): cartilaginous joint between the body of sphenoid bone and basilar part of the occipital bone that ossifies after the age of 18. (synostosis) Petrooccipital synchondrosis (Synchondrosis petrooccipitalis): permanent cartilaginous joint between petrous part of temporal bone and the occipital bone. Partes laterales: Jugular tubercle (Tuberculum jugulare): an elevation just above the hypoglossal canal. Hypoglossal canal (Canalis hypoglossi): contains the hypoglossal nerve. Jugular notch (Incisura jugularis): It is divided into two parts by the intrajugular process. It forms the number „8”-shaped jugular foramen with the jugular notch of the petrous bone. The anteromedial smaller part of the jugular foramen contains the IX., X., XI. cranial nerves, and the superior sensory ganglia of the glossopharyngeal and vagus nerves. The posterolateral larger part of the foramen contains the internal jugular vein. Sulcus for the sigmoid sinus (Sulcus sinus sigmoidei): contains the sigmoid sinus that extends to the jugular foramen. Condylar fossa (Fossa condyloidea): a depression behind the occipital condyles into which there usually opens a condylar canal that transmits a vein. Occipital condyles (Condyli occipitales): represent the articular surface of atlantooccipital joints. Squama occipitalis: 7 External occipital protuberance (Protuberantia occipitalis externa): a projection on the posterior surface of the occipital squama. Internal occipitalis protuberance (Protuberantia occipitalis interna): a projection on the internal surface of the occipital squama. External occipital crest (Crista occipitalis externa): a ridge extending downward in the midline from the external occipital protuberance. Internal occipital crest (Crista occipitalis interna): a ridge extending downward in the midline from the internal occipital protuberance. Sulcus for the superior sagittal sinus (Sulcus sinus sagittalis superioris) Sulcus for the transverse sinus (Sulcus sinus tansversi) Sulcus for the sigmoid sinus (Sulcus sinus sigmoidei) Cerebellar fossa (Fossa cerebellaris): accommodates the cerebellar hemispheres. Cerebral fossa (Fossa cerebralis): contains the occipital lobes. Lineae nuchae suprema, superior, inferior: points of trapezius, semispinalis and deep nuchal muscle attachments. 8 Sphenoid bone (os sphenoidale): unpaired bone resembling a flying bat. It’s involved in the formation of both the base of the skull and viscerocranium. Parts: 1.Body: encloses the sphenoid sinus (one of the paranasal sinuses) Ant. surface: Aperture of the sphenoid sinus (Apertura sinus sphenoidalis): opens into the nasal cavity. Inferior surface: gives rise to the pterygoid process and borders the choanae. Posterior surface: Synchondrosis sphenooccipitalis: cartilaginous joint (in adult it becomes synostosis) between the posterior surface of the body and basilar part of the occipital bone, forming the clivus. Lateral surfaces:gives rise to the greater wing. Carotid sulcus (Sulcus caroticus): contains the internal carotid artery after leaving the carotid canal. Superior surface:gives rise to the lesser wing, and forms the sella turcica. Chiasmatic sulcus(Sulcus chiasmatis): the optic chiasm rests just above it. Tuberculum sellae: anterior border of the hypophysial fossa Fossa hypophysealis: contains the hypophysis. Dorsum sellae: posterior border of the hypophysial fossa Anterior clinoid process (Processus clinoideus anterior): bony process fixing the sellar diaphragm anteriorly. Middle clinoid process (Processus clinoideus medius) bony process fixing the sellar diaphragm laterally. Posterior clinoid process (Processus clinoideus posterior) bony process fixing the sellar diaphragm posteriory. Ala minor: Optic canal (Canalis opticus): contains the optic nerve and the ophthalmic artery. Fissura orbitalis superior (its upper border is the ala minor): contains the oculomotor, trochlear, ophthalmic and abducent nerves, superiorophthalmic vein. Greater wing (Ala major): Cerebral surface (Facies cerebralis): involved in the formation of the middle cranial fossa. Temporal surface (Facies temporalis): involved in the formation of the temporal fossa. 9 Infratemporal surface (Facies infratemporalis) involved in the formation of the infratemporal fossa. Infratemporal crest (Crista infratemporalis): a ridge separating the temporal fossa from the infratemporal one. Orbital surface (Facies orbitalis): involved in the formation of the lateral wall of the orbit. Maxillary surface (Facies maxillaris): faces the pterygopalatine fossa, the foramen rotundum visible on it. Foramen rotundum: leads to the pterygopalatine fossa, contains the maxillary nerve. Foramen ovale: opens into the infratemporal fossa, contains the mandibular nerve. Foramen spinosum: opens into the infratemporal fossa, the middle meningeal artery passes through it from the infratemporal to the middle cranial fossa. Superior orbital fissure (Fissura orbitalis superior): its lower border is the ala major. Inferior orbital fissure (Fissura orbitalis inferior): formed by the geater wing and orbital surface of the maxilla, connects the orbit with the infratemporal and pterygopalatine fossae.Items: zygomatic and infraorbital nerves, infraorbital vessels, inferior ophthalmic vein. Pterygoid process (Processus pterygoideus): o Medial and lateral pterygoid plates (Lamina medialis et lateralis processus pterygoidei) o Fossa pterygoidea: depression between the medial and lateral pterygoid plates for the origination of the medial pterygoideus muscle. o Fossa scaphoidea: contains partly the origination of the tensor veli palatini muscle and the pharyngeal ostium of the auditory tube. o Vidian canal (Canalis pterygoideus Vidii): connects the external surface of the base of the skull with the pterygopalatine fossa.Items: Vidian neve (consists of the greater and deep petrosal nerves) o Pterygoid hamulus (Hamulus pterygoideus): hooklike process of the medial pterygoid plate. 10 Frontal bone (os frontale): unpaired bone involves in the formation of the forehead and anterior part of the base of the skull. Parts: Squama frontalis: Coronal suture (Sutura coronalis): between the two parietal bones and the frontal bone. Temporal surface (Facies temporalis): it takes part in the formation of the temporal fossa. Zygomatic process (Processus zygomaticus): connects with the zygomatic bone. Frontal tuber (Tuber frontale): ossification centre in the embryonic life. Supraorbital margin (Margo supraorbitalis): superior border of the aditus orbitae. Superciliary arch (Arcus superciliaris): bony ridge just above and paralleling the supraorbital margin. Glabella: very slight protuberance between the superciliary arches. Supraorbital foramen (Foramen supraorbitale / incisura supraorbitalis): opening or notch on the inner third of the supraorbital margin containing the supraorbital vessels and nerve. Frontal notch (Incisura frontalis / foramen frontale): notch or foramen on the inner third of the supraorbital margin medially to the supraorbital foramen containing the frontal vessels and nerve. Frontal crest (Crista frontalis): bony ridge on the inner surface of the squama for the fixation of the cerebral falx. Foramen cecum: blind opening at the root of the frontal crest , but in childhood an emissary vein passes through it. Groove for the superior sagittal sinus (Sulcus sinus sagittalis superioris): contains a potion of the superior sagittal sinus. Grooves of the anterior meningeal artery (Sulcus arteriae meningeae anterioris): they contain the branches of the anterior meningeal artery. Orbital parts (Partes orbitales): form a part of the roof of the orbit. Ethmoidal notch (Incisura ethmoidalis): a notch separating the two orbital parts. Ethmoidal foveolae (Foveolae ethmoidales): small depressions along the two sides of the ethmoidal notch that take part in the formation of some ethmoidal air-cells. Anterior and posterior ethmoidal foramina (Foramina ethmoidalia anterius et posterius): openings of the anterior and 11 posterior ethmoidal canals at the junction of the orbital part of the frontal bone and the orbital lamina of the ethmoidal bone, containing the ant. and post. ethmoidal vessels and nerves. Fossa of the lacrimal gland (Fossa glandulae lacrimalis): contains the lacrimal gland. Trochlear spine (Spina trochlearis): small bony hook for the attachment of the tendon of the superior obliquus bulbi muscle. Impressiones digitatae: they are visible on the cerebral surface and the frontal gyri lie in them. Juga cerebralia: small elevations having the sulci separating the frontal gyri just lying on them. Nasal part(Pars nasalis):connects anteriorly the two orbital parts. Nasal spine (Spina nasalis): small bony spine connecting with the nasal bones. Frontal sinus (Sinus frontalis): paranasal sinus in the squama, having its opening on the two sides of the nasal spine 12 Bones of the viscerocranium: 1.Os ethmoidale: unpaired bone inserted into the ethmoidal notch of the frontal bone. Main parts: perpendicular plate, cribriform plate, ethmoidal labyrinth. Perpendicular plate (Lamina perpendicularis): bony lamina projecting downward forming the upper portion of the nasal septum. Crista galli: it is the process of the perpendicular plate projecting upward into the cranial cavity for attachment of cerebral falx. Cribriform plate (Lamina cribrosa): horizontal bony lamina between the nasal cavity and the anterior cranial fossa. It is perforated for the passage of olfactory fibers, anterior ethmoidal vessels and nerve. Ethmoidal labyrinth (Labyrinthus ethmoidalis) /Ethmoidal air-cells (Cellulae ethmoidales): they are located between the orbit and nasal cavity, belong to the paranasal sinuses and open into the nasal cavity.They are divided anterior, middle and posterior groups of the air-cells. Orbital lamina (Lamina orbitalis / lamina papyracea): it is a very thin bony lamina closing the ethmoidal labyrinth on the orbital side. Anterior and posterior ethmoidal canals (Canales ethmoidales anterior et posterior): they are formed by the frontal bone and the orbital lamina, containing the anterior and posterior ethmoidal vessels and nerves. Superior nasal concha (Concha nasalis superior): bony process projecting into the nasal cavity and closing the posterior ethmoidal air-cells on their nasal side. Below the superior nasal concha the superior nasal meatus is located. Middle nasal concha (Concha nasalis media): bony process projecting into the nasal cavity below the superior nasal concha and meatus, and closing the anterior ethmoidal air-cells on their nasal side. Below the middle nasal concha the middle nasal meatus is located. Ethmoidal bulla (Bulla ethmoidalis): largest anterior ethmoidal air-cell above the semilunar hiatus. 13 Uncinate process (Processus uncinatus): hooklike process directed backward and downward almost wholly concealed by the middle nasal concha. It partially closes the semilunar hiatus. Semilunar hiatus (Hiatus semilunaris): semilunar opening bordered superiorly by the ethmoidal bulla and inferiorly by the uncinate process through which the the frontal sinus, anterior and middle ethmoidal air-cells and maxillary sinus open into the middle nasal meatus. Ethmoidal infundibulum (Infundibulum ethmoidale):funnelshaped canal passing through the ethmoidal labyrinth extending from frontal sinus to semilunar hiatus. 14 2. Maxilla: upper jaw I.Corpus maxillae: the central portion of the maxillary bone containing the maxillary sinus. It has 4 surfaces: Facies anterior/facial surface: Infraorbital margin (Margo infraorbitalis): inferior border of the orbit formed by the maxilla. Infraorbital foramen (Foramen infraorbitale): opening of infraorbital canal containing the infraorbital nerve and accompanying artery. Pressure point for the maxillary division of the trigeminal nerve. Infraorbital canal (canalis infraorbitalis): for the infraorbital artery and nerve. It gives rise canalicules containing nerves supplying the anterior-superior teeth. Canine fossa (Fossa canina): depression below the infraorbital foramen for origin of the levator anguli oris muscle (facial muscle). Orbital surface (Facies orbitalis / superior):forms part of the orbital floor Inferior orbital fissure (Fissura orbitalis inferior): between greater wing of sphenoid bone and orbital surface of the maxilla for passage of the zygomatic and infraorbital nerves and vessels. Infraorbital sulcus(Sulcus infraorbitalis): groove at the beginning of the infraorbital canal. Canalicules originating from infraorbital sulcus contain nerves supplying the middle-superior teeth. Infratemporal surface (Facies infratemporalis/ posterior): posterior surface of maxilla behind the zygomatic process. Tuberosity of maxilla (Tuber maxillae): thin-walled prominence on the posterior wall of the maxillary sinus. Alveolar foramina (Foramina alveolaria): small openings in the infratemporal surface for branches of the posterior superior alveolar artery and nerve. Alveolar canals (Canales alveolares): canals from the alveolar foramina for branches of the posterior superior alveolar artery and nerves. 15 Nasal surface (Facies nasalis):medial surface of maxilla forming part of the lateral nasal wall. Maxillary hiatus (Hiatus maxillaris) (sinus maxillaris / Highmore sinus: large opening in the medial wall of maxillary sinus Lacrimal sulcus (sulcus lacrimalis): groove for the nasolacrimal duct. Conchal crest (crista conchalis): nearly horizontal ridge for attachment of the inferior nasal concha. Greater palatine sulcus ( sulcus palatinus major): groove along the posterior border of maxilla which, with the greater palatine sulcus of the palatine bone, forms the greater palatine canal for the greater palatine nerve and descending palatine artery. II.Frontal process (Processus frontalis): Anterior lacrimal crest (Crista lacrimalis anterior): bony ridge bordering the fossa of the lacrimal sac anteriorly. III.Zygomatic process (Processus zygomaticus): laterally directed process for articulation with the zygomatic bone. IV.Alveolar process (Processus alveolaris): crest-like process forming sockets for the teeth. Superior alveolar arch (Arcus alveolaris superior): arcuate free border of the alveolar process. Dental alveoli (Alveoli dentales): cavities in the alveolar process for the root of the teeth. Interalveolar septa (Septa interalveolaria): bony crest between the alveoli. Interradicular septa (Septa interradicularia): bony walls between chambers of a dental alveolus for the root of a tooth. Alveolar juga (juga alveolaria): prominences on the external surfaces of the jaw caused by the sockets of the teeth. Incisive foramen (foramen incisivum): opening of incisive canal into the oral cavity. V.Palatine process (Processus palatinus): horizontal plate forming the largest portion of the hard palate. Median palatine suture (Sutura palatina mediana): suture running in the midline of hard palate between palatine processes of maxillary bones and horizontal plates of the palatine bones. 16 Transverse palatine suture (Sutura palatina transversa): transversally running suture of the hard palate between palatine processes of maxillae and palatine bones. Nasal crest (Crista nasalis): bony crest in the midline for attachment of the nasal septum. Anterior nasal spine (Spina nasalis anterior): sharp projection below the piriform aperture (anterior opening of bony nasal cavity) for attachment of the cartilaginous nasal septum. Incisive bone (Os incisivum, premaxilla): intermaxillary bone that develops separatelly from maxilla.Usually extends from incisive foramen to gap between canine tooth second incisor. Incisive suture (Sutura incisiva): between palatine process and incisive bone visible only during development. Incisive canal (Canalis incisivus): passage for the nasopalatine nerve. It is double on the nasal side, single on the palatine side. 17 3. Zygomatic bone (Os zygomaticum): forms a large portion of the lateral wall of the orbit and part of the zygomatic arch. It has 3 surfaces: Lateral surface (Facies lateralis): facing laterally. Temporal surface (Facies temporalis): facing temporal fossa. Orbital surface (Facies orbitalis): facing the orbit. Processes: Frontal process (Processus frontalis): adjoining the zygomatic process of the frontal bone. Temporal process (Processus temporalis): with the zygomatic process of the temporal bone forms the zygomatic arch. Maxillary process (Processus maxillaris): adjoining the maxilla. Zygomaticoorbital foramen (Foramen zygomaticoorbitale): opening of the canal for the zygomatic nerve on the orbital surface. Zygomaticofacial foramen (Foramen zygomaticofaciale): opening on the lateral surface for passage of the zygomaticofacial branch of the zygomatic nerve. Zygomaticotemporal foramen (Foramen zygomaticotemporale): opening on the temporal surface for passage of the zygomaticotemporal branch of the zygomatic nerve. 4. Lacrimal bone (Os lacrimale): located in front of the orbital lamina of the ethmoidal bone. Lacrimal sulcus (Sulcus lacrimalis): involved in the formation of the fossa for the lacrimal sac. Posterior lacrimal crest (Crista lacrimalis posterior): bony ridge bordering posteriorly the lacrimal sac. Fossa for the lacrimal sac (Fossa sacci lacrimalis): contains the lacrimal sac. Nasolacrimal canal(Canalis nasolacrimalis): contains the nasolacrimal duct opening into the inferior nasal meatus of the nasal cavity. 4. Nasal bone (os nasale): paired bone between right and left maxillary bones, connects superiorly to the frontal bone. Ethmoidal sulcus (Sulcus ethmoidalis): on lower surface of the nasal bone for the external nasal branch of the anterior ethmoidal nerve. 18 6.Vomer: unpaired bone taking part in the formation of the bony nasal septum. Ala of vomer (Ala vomeris): wing-like process supporting the sphenoid bone and connects to the nasal crest. 7.Inferior nasal concha (Concha nasalis inferior): independent lower concha attached to lateral wall of nasal cavity. Maxillary process (Processus maxillaris): lateral process forming part of medial wall of maxillary sinus. Lacrimal process (Processus lacrimalis): directed forward and upward. Ethmoidal process (Processus ethmoidalis): connected to the uncinate process of ethmoid bone. 19 8. Palatine bone (Os palatinum): forms the posterior extention of the upper jaw. It consists of 2 plates: perpendicular and horizontal plates. Perpendicular lamina (Lamina perpendicularis): between pterygoid process and nasal part of maxilla. It forms a part of the medial wall of the maxillary sinus. It has 2 surfaces: nasal surface and maxillary surface. Nasal surface (facies nasalis): facing the nose. Maxillary surface (facies maxillaris): lateral surface of the perpendicular plate adjoining both the pterygopalatine fossa and maxillary sinus. Sphenopalatine notch (Incisura sphenopalatina) part of the sphenopalatine foramen at the upper border of the perpendicular plate. Orbital process (Processus orbitalis): process between the maxilla, ethmoid and sphenoid bones directed forward and upward. Sphenoid process (Processus sphenoidalis): superior process behind the sphenopalatine notch. Ethmoidal crest (Crista ethmoidalis): ridge for attachment of the middle concha. Conchal crest (Crista conchalis): ridge for the attachment of the inferior concha. Greater palatine sulcus (sulcus palatinus major): groove which, with the greater palatine sulcus of the maxilla, forms the greater palatine canal for the greater palatine nerve and descending palatine artery. Pyramidal process (Processus pyramidalis): process inserted into the pterygoid notch. Horizontal lamina (Lamina horizontalis): forms the posterior part of the hard palate. It has 2 surfaces: nasal and palatine surfaces. Greater palatine foramen (Foramen palatinum majus): opening of the greater palatine canal in the palatine surface. Lesser palatine foramina(Foramina palatina minora) openings of the canales palatini minores in the palatine surface. Nasal crest (Crista nasalis): median bony ridge at the juncture with the opposite palatine bone. Posterior nasal spine (Spina nasalis posterior):apex of the nasal crest extending posterioly and medially at the junion with the opposite palatine bone. 20 9. Mandibula (lower jaw): Body (Corpus mandibulae): horizontal portion of the lower jaw to which the rami are attached. Base of the mandible (Basis mandibulae): lower part of the mandibular body without alveolar portion. Alveolar part (Pars alveolaris): crest on the base for reception of the roots of the teeth. Limbus alveolaris: alveolar margin Dental alveoli (Alveoli dentales): sockets for the roots of the teeth. o Interalveolar septa (Septa interalveolaria): bony crest between the tooth sockets. o Interradicular septa (Septa interradicularia): bony crests between the roots of a tooth. Alveolar juga( juga alveolaria): prominences on the external surface of the mandible caused by the roots of the teeth. Mental protuberance (Protuberantia mentalis): the chin. Mental tubercle (tuberculum mentale): paired tubercle located inferiorly on the mental tuberance. Mental foramen (Foramen mentale): External opening of the mandibular canal for the mental nerve beneath the second premolar. Pressure point for the mandibular branch of the trigeminal nerve. Mandibular canal (Canalis mandibulae): canal for the inferior alveolar nerve and artery running inside the mandible starting with the mandibular foramen and ending with the mental foramen. Mental spine (Spina mentalis): small bony hook in the midline on the inner surface for origin of genioglossus and geniohyoid muscles. Mylohyoid line ( Linea mylohyoidea): extends diagonally from a postero-superior to an antero-inferior point, serving as a line of origin for the mylohyoideus muscle. Sublingual fovea (Fovea sublingualis): depression for the sublingual gland laterally to the mental spine, above the mylohyoid line on the inner surface. Submandibular fovea (fovea submandibularis): depression for the submandibular gland below the mylohyoid line on the inner surface. 21 Digastric fossa (Fossa digastrica): small fossa located anteriorly on the inner surface, above the inferior border, for the insertion of the digastric muscle Angle of the mandible (Angulus mandibulae): angle between body and ramus. Masseteric tuberosity (Tuberositas masseterica): bony crest of the external surface of the mandible for attachment of the masseter muscle. Pterygoid tuberosity (Tuberositas pterygoidea): rough area on the internal surface of the mandible near the angle for attachment of the medial pterygoid muscle. Ramus mandibulae: the ascending portion. Condylar process (Processus condylaris): ends as the head of the mandible. Head of the mandible (Caput mandibulae): articular head of the temporomandibular joint. Neck of the mandible (Collum mandibulae): slender portion below the condyle. Coronoid process (Processus coronoideus): process for the attachment of the temporalis muscle.It is separated from the posteriorly located condylar process by the mandibular notch. Mandibular notch (Incisura mandibulae): between the condylar and coronoid processes. Mandibular foramen (Foramen mandibulae): opening of the mandibular canal on the inner surface of the mandibular ramus. Lingula of mandible (Lingula mandibulae): bony lamina anterior to the mandibular foramen. Mylohyoid sulcus (Sulcus mylohyoideus): groove running forward and downward from the mandibular foramen carrying the mylohyoid nerve and the mylohyoid branch of the inferior alveolar artery. 22 Calvaria: Tuber frontale Tuber parietale Sutura sagittalis Sutura coronalis Sutura lambdoidea Sutura squamosa Sulcus sinus sagittalis superioris Foveolae granulares Sulci arteriosi Diploe, lamina externa et interna Canales diploicae Basis cranii interna: Fossa cranii anterior / scala anterior: Crista galli Lamina cribrosa Foramen cecum Sulcus chiasmatis Canalis opticus Processus clinoideus anterior Juga cerebralia Fossa cranii media / scala media: Sella turcica Fossa hypophysealis Processus clinoideus media et posterior Tuberculum sellae Dorsum sellae Sulcus caroticus Canalis caroticus Foramen lacerum Fissura sphenopetrosa Fissura orbitalis superior Foramen rotundum Foramen ovale Foramen spinosum Sulci arteriosi Impressio trigemini / Meckel-árok Hiatus canalis nervi petrosi majoris et minoris Sulcus nervi petrosi majoris et minoris Eminentia arcuata 23 Tegmen tympani Sulcus sinus petrosi superioris Fossa cranii posterior / scala posterior: Foramen magnum Tuberculum jugulare Canalis hypoglossi Foramen jugulare Porus acusticus internus ( meatus acusticus internus) Apertura externa aqueductus vestibuli Sulcus sinus petrosi inferioris Sulcus sinus sigmoidei Sulcus sinus transversi Sulcus sinus sagittalis superioris Protuberantia occipitalis interna Crista occipitalis interna Clivus Synchondrosis petrooccipitalis Basis cranii externa: Fossa scaphoidea Sulcus tubae auditivae Canalis musculotubarius Foramen lacerum Canalis pterygoideus Vidii Foramen ovale Foramen spinosum Tuberculum articulare Fossa mandibularis Processus zygomaticus Fissura petrosquamosa Fissura petrotympanica Glaseri Processus mastoideus Foramen stylomastoideum Processus styloideus Fossa jugularis Foramen jugulare Canalis caroticus Fossula petrosa Apertura inferior canaliculi tympanici Apertura externa canaliculi cochleae Canalis hypoglossi 24 Sulcus arteriae occipitalis Incisura mastoidea CONNECTIONS OF THE ORBIT: canalis opticus cranial cavity optic nerve ophthalmic artery sup. orbital fissure middle cranial fossa oculomotor n. trochlear n. ophthalmic n. abducent n. sup. ophthalmic vein inf. orbital fissure pterygopalatine fossa: infratemporal fossa: infraorbital a. & n. zygomatic nerve inferior ophthalmic vein ant. ethmoidal foramen ant. cranial fossa ant. ethmoidal a. & n. post. ethmoidal foramen ethmoidal air-cells post. ethmoidal a. & n. nasolacrimal canal inf. nasal meatus nasolacrimal duct infraorbital foramen fossa canina infraorbital a. & n. frontal notch forehead frontal a. & n. supraorbital foramen forehead supraorbital a.& n. zygomatic canal aditus orbitae face: zygomaticofacial c. temporal fossa: zygomaticotemporal canal zygomatic nerve face CONNECTIONS OF THE NASAL CVITY: piriform aperture face 25 choanae pharynx sphenopalatine foramen pterygopalatine fossa semilunar hiatus maxillary sinus frontal sinus ( with ethmoidal infundibulum) ant., middle ethmoidal air-cells sup. nasal meatus post. ethmoidal air -cells aperture of sphenoidal sinus ( sphenoethmoidal recess) sphenoidal sinus nasolacrimal canal (inferior nasal meatus) incisive canal orbit sphenopalatine a. post. nasal nn. nasolacrimal duct oral cavity end-branch of sphenopalatine a. post. med. nasal nerve CONNECTONS OF THE PTERYGOPALATINE FOSSA: foramen rotundum middle cranial fossa sphenopalatine foramen maxillary nerve nasal cavity sphenopalatine artery post. nasal nerves pterygoid canal/Vidian canal ext. surface of the base of the skull greater petrosal nerve deep petrosal nerve inf. orbital fissure orbit infraorbital nerve zygomatic nerve greater palatine canal oral cavity pterygomaxillary fissure infratemporal fossa greater palatine nerve descending palatine artery post. sup. alveolar nerves sphenopalatine artery 26 27