Osteology exam 2 Flashcards
Mandible body (corpus or horizontal ramus)
Thick bony part that anchors teeth
Mental foramen
On lateral corpus surface. Transmits mental vessels and nerve.
Oblique line
Weak eminence that passes from root of ramus to area at rear of mental foramen.
Extramotor sulcus
Gutter between root of anterior edge of ramus and lateral alveolar margin of last molar. Gives rise to buccinator muscle of cheek.
Mylohyoid line
Crosses medial surface of corpus, begining near alveolar margin at last molar position and diminishing as it runs anteroinferiorly. Attachment site for mylohyoid muscle which elevates tongue.
Submandibular fossa
Hollow beneath alveolar portion that runs along medial corpus. Inferior to mylohyoid line. Submandibular gland rests here.
Sublingual fossa
Hollowing beneath alveolar region, superior to mylohyoid line in premolar region. Sublingual gland rests here.
Mandibular torus
Variably developed thickening of alveolar margin.
Mandibular symphisis
Midline surfaces of unfused halves.
Mental spines
Lie near inferior margin of inner surface of anterior corpus. Anchor genioglossal and geniohyoid muscles.
Digastric fossae
Pair of roughened depressions on posteroinferior aspect of corpus adjacent to midline. Attachment sites for digastric muscles.
Mental protuberance (eminence)
Bony chin at base of corpus. Separated from alveolar margins of incisors by pronounced incurvation.
Ramus
Thinner than corpus. Articulates with cranial base.
Mandibular condyle
On posterosuperior corner of ramus. Articulates with TMJ.
Condylar neck
Justt anteroinferior to condyle. Head of lateral pterygoid muscle attaches to anteromedial surface of neck just below articular surface of confdyle in pterygoid fovea.
Coronoid processes
Thin and triangular. Recieve insertion of temporalis muscle.
Mandibular notch (incursura)
Notch between condyle and coronoid process.
Angle (gonial angle)
Rounded posteroinferior corner of mandible.
Masseteric tuberosity
Raised, roughened area at lateral edge of gonial angle where masseter muscle attaches.
Masseteric fossa
Hollowing on lateral surface of gonial angle.
Endocoronoid ridge (buttress)
Vertical ridge extending inferiorly from coronoid tip on inner (medial) aspect of ramus.
Mandibular foramen
Enters bone obliquely, centred in medial surface of ramus. Alveolar vessels and inferior alveolar nerve enter bone here.
Lingula
Sharp projection at edge of mandibular foramen. Attachment point for sphenomandibular ligament.
Mylohyoid groove
Crosses medial surface of ramus, running anteroinferiorly from edge of mandibular foramen. Lodges mylohyoid vessels and nerve.
Pterygoid tuberosities
Interrupt medial surface of gonial angle posteroinferior to mylohyoid groove. Mark insertion of medial pterygoid muscle, an elevator of the mandible.
Body of sphenoid
Midline. Most substantial part. Anterior surface forms superoposterior wall of nasal cavity and articulates with cribriform plate and perpendicular plate of ethmoid. Posteriorly articulates with occipital at sphenooccipital suture. Anteroinferiorly articulates with vomer.
Optic canals
Either side of body of sphenoid. Optic never and opthalmic artery pass through.
Sella turcica
Saddle-shaped depression on endocranial surface of sphenoid. Located endocranially,posterior and inferior to optic canals.
Hypophyseal (pituitary) fossa
Deepest depression of sella. Hold pituitary gland.
Dorsum sellae
Square plate of bone that forms posterior boundary of sella turcica.
Posterior clinoid process
Two highly variable tubercles at superolateral corners of dorsum sellae.
Clivus
Slight endocranial hollow that slopes posteriorly from dorsum sellae toward sphenooccipital suture.
Sphenoidal sinuses
Paired hollows in body
Sphenoidal rostrum
Midline bony projection on anteroinferior surface of body. Fits into fissure between alae of vomer.
Sphenoidal crest
Continuous with rostrum, extending superiorly from it on anterior surface of body. Articulates with perpendicular plate of ethmoid and forms part of septum.
Greater wings
Extend laterally from body. Articulate with temporals, parietals, frontal, zygomatics and maxillae.
Superior orbital fissures
Open spaces between inferior surfaces of lesser wings and anterior surfaces of greater wings.
Foramen rotundum
Most anterior and medial part of the middle cranial fossae at junction of greater wings and body. Transmit maxillary nerves.
Foramen ovale
Located posterior to foramen rotundum on each side, approx in line with dorsum sellae. Transmit mandibular nerves and accessory meningeal arteries.
Foramen spinosum
On each greater wing just posterolateral to foramen ovale. Transmit middle meningeal vessels and branches from mandibular nerves.
Infratemporal crests
Form base of temporal fossae at about level of zygomatic arches.
Orbital surfaces
Form lateral wall of each orbit. V. smooth and flat compared to endocranial surfaces.
Lesser wings
Partially floor right and left frontal lobes. Arise from superior surface of body and articulate with horizontal orbital plates of frontal.
Anterior clinoid procesesses
Posteriormost projections of lesser wings. Attachment for tentorium cerebelli, a segment of dura mater separating cerebellum from occipital part of cerebral hemispheres of brain.
Pterygoid processes
Divided into 2 plates. Visible on from side or below cranium.
Lateral pterygoid plate (lamina)
Thin vertical plate of bone seen in lateral view.
Medial pterygoid plate (lamina)
Thin vertical plate of bone. Each pair of pterygoid plates articulates with palatines. These 4 thin projections provide attachment for medial pterygoid muscles, mandibular elevators.
Pterygoid fossae
Hollows between medial and lateral pterygoid plates
Pterygoid hamulus
Hook-like process forming the posterolateral, basal corner of each medial pterygoidal plate.
Pterygoid canals
Perforate the bone above the pterygoid plates and run along base of plates.
Frontal process
Rises vertically and separates orbit from temporal fossa.
Temporal process
Extends posteriorly, joining zygomatic process of temporal bonetemporal bone to form zygomatic arch.
Maxillary process
Extends toward midline, forming inferolateral orbital margin.
Zygomaticofacial foramen
Perforates convex lateral surface of zygomatic. Allows passage of zygomaticofacial nerve and vessels.
Masseteric origin
Roughened, expanded inferior edge of bone, extends from zygomaticomaxillary to temporozygomatic suture. Main attachment for masseter muscle, a major elevator of mandible.
Zygomaticoorbital foramina
Perforate inferolateral corner of orbital cavity for passage of the zygomaticotemporal and zygomaticofacial nerves.
Zygomaticotemporal foramen
Centered on temporal surface of of zygomatic. Transmits zygomaticotemporal nerve.
Nasal foramen
Perforates facial and transmits a vein
Posterior lacrimal crest
Vertical crest on medial orbital wall that bounds posterior half of lacrimal groove.
Cribriform plate
Roofs nasal cavities and looks like a sieve due to foramina. Olfactory nerves perforate this plate as they pass up to the brain from mucous lining of nose.
Crista galli
Perpendicular projection of cribriform plate of ethmoid into endocranial cavity. Interposed between olfactory bulbs and posterior surface anchors falx cerebri, a fold of dura mater extending to between the hemispheres.
Labyrinths or lateral masses
Lie either side of midline. The lateral plates form most of the medial orbital walls, and the medial plates form the upper walls of the nasal cavity.
Perpendicular plate
A flattened lamina placed at midline between the lateral masses. Forms part of nasal septum and articulates inferiorly with vomer.
Vomer alae
Either side of deep midline furrow on superior surface
Perpendicular plate of vomer
Thin vertical sheet of bone on midline below wings
Posterior border
Divides posterior nasal aperture into two halves.
Nasopalatine grooves.
Lodge nasopalatine nerves and vessels, marking both sides of perpendicular plate.
Horizontal plate
Forms posterior third of hard palate
Greater palatine foramen
Perforates rear corner of hard palate and is formed as the alveolar process of the maxilla meets the horizontal plate of palatine. Transmits greater palatine vessels and nerve.
Pterygopalatine canal
2 halves. Sweep posterosuperiorly when maxilla and perpendicular plate of palatine are disarticulated.
Posterior nasal spine
Located on superior surface of horizontal plate.
Lesser palatine foramina
For transmission of lesser palatine nerves, located on posterolateral corner of hard palate posterior to greater palatine foramina, near junction of perpendicular and horizontal plates.
Perpendicular plate
Appressed tightly to posteromedial wall of maxilla opposite maxillary sinus, between pterygoid plates of sphenoid and posterior margin of alveolar process of maxilla.
Pyramidal process
Posterior border of perpendicular plate (the thickest border)
Conchal crest
Almost halfway perpendicular plate on medial surface. For articulation with inferior nasal conchae.
Alveolar process
Horizontal portion of maxilla that holds tooth roots
Alveoli
For tooth roots, present along alveolar process unless resorbed
Canine jugum
Bony eminence over maxillary canine root on facial surface of maxlila.
Zygomatic process
Forms much of cheek
Infraorbital foramen
Below inferior orbital rim on facial surface and transmits infraorbital nerve and vessels to face.
Canine fossa
Hollow on facial surface just below infraorbital foramen where zygomatic, frontal and alveolar processes meet.
Anterior nasal spine
Thin projection of bone on midline at inferior margin of nasal aperture.
Infraorbital sulcus
Centred on posterior half of orbital floor. Connects anteroinferiorly with infraorbital foramen via infraorbital canal.
Maxillary sinus
Large void in body of maxilla superior to alveolar process and inferior to orbital floor.
Frontal process
Rises to articulate with frontal, asals, lacrimals and ethmoid.
Anterior lacrimal crest
Vertical crest on lateral aspect of frontal process of maxilla. Maxilla combines with lacrimal bone to form lacrimal groove and canal.
Palatine process
Forms anterior 2 thirds of hard palate and floor of nasal cavity.
Incisive foramen
Perforates anterior hard palate at midline.
Incisive canal
Each lobe of canal transmits the terminal branch of the greater palatine artery and the nasopatine nerve
Premaxillary suture
Sometimes seen in wall of incisive canal and on adjacent palatal surface.
Greater palatine groove
At rear of hard palate marks junction of palatine and alveolar processes. For greater palatine vessels and nerve.
Maxillary tuber
Rugose surface at posterior end of alveolar process.
Nasoalveolar clivus
Surface between canine jugae, the base of the piriform aperture and the alveolar margin.
