Bones of the Skull (2)

Obellion

Noticeable flat area between the 2 parietal foramen from the parietal bone; space between parietal foramina.

Parietomastoid and Occipitomastoid Sutures

Frequently contains one or more sutural bones; part of the parietal bone (2).

External Occipital Protuberance

Near the middle of the occipital squama and extending lateralward from it on either side is the superior nuchal line, and above this the faintly marked highest nuchal line.

Planum Occipitale

Part of the squama above the inion and highest lines; covered by the occipitalis muscle.

Planum Nuchale

Below the planum occipitale and is divided by the median nuchal line which runs downward and forward from the inion to the foramen magnum.

Planum Nuchale

This ridge gives attachment to the ligamentum nuchae.

Mastoid Process

Convex laterally and grooved medially by the mastoid notches.

Mastoid Foramen

In or near the occipitomastoid suture for the passage of the mastoid emissary vein.

Supreme Nuchal Line

Highest and less remarkable than the other two.

Superior Nuchal Line

Look for the inion; extend bilaterally from the inion.

Inferior Nuchal Line

Below the superior.

Body of Maxilla

Contains the maxillary sinus or antrum of highmore.

Infraorbital Foramen

Opening for the passage of the terminal branches of the maxillary division of the CNV; located below the oral cavity.

Canine Fossa

Depression lateral to the canine eminence; located at the body of the maxilla.

Anterior Lacrimal Crest

Rim of the infraorbital margin.

Infraorbital Groove

Exposed part that will follow the infraorbital foramen; used by the infraorbital nerve in passing out of the cranium.

Superciliary Arch

Identifies the landmark of the eyebrows; elevation above the orbital cavity.

Glabella

Between the medial ends of the superciliary arch; indicates the position of the frontal sinus.

Frontal Eminence

Most convex landmark of the frontal bone.

Supraorbital Notch

Opening at the highest point of the supraorbital margin; for the passage of the frontal nerve or supraorbital nerve.

Notch

If there’s an indentation or does not form a circle that is bordered by a bone.

Foramen

If the opening is bordered by a bone.

Orbital Portion of the Frontal Bone

Will form the roof of the orbital cavity; will form the floor of the anterior cranial fossa.

Anterior Nasal Spine

Prominent projection at the base of the nasal cavity.

Intermaxillary Suture

Fuses the 2 maxillary bones together.

Malar Prominence

Perforated by the zygomatic facial foramen.

Zygomatic Process

Is the articulation with the zygomatic bone.

Maxillary Process

Is the part of the zygomatic bone in articulation with the maxillary bone.

Lacrimal Groove

Bounded by the posterior lacrimal bone and the anterior lacrimal bone; where the lacrimal sac is located.

Greater Wing of Sphenoid

Laterally located to the sphenoid.

Optic Canal

Medially located; rounded opening in the apex; bounded by the roof of the lesser wing and on its opposite side is the greater wing of sphenoid.

Lamina Papyracea

Orbital part of ethmoid bone.

Ethmoidal Foramen

Two foramina are located anteriorly and posteriorly.

Symphysis Menti

Mark that indicates the union of the 2 parts of the mandible.

Mental Tubercle

Prominent corners of mental protuberance.

Incisive Fossa

Depressions found in the roots of the mandibular incisors; not foramen or canal.

Subnasal Fossa

Depressions in the root of the maxillary incisors; located below the nasal cavity.

Orbital Cavity

Is like an inverted pyramid with the convergence of four walls.

Nasion

Junction between the frontonasal suture and internasal suture.

Infraorbital Margin

Formed by maxilla (medially) and zygomatic bone (laterally).

Piriform Aperture

Anterior opening of the nasal cavity.

Zygomatico Maxillary Arch

Between the maxilla and zygomatic bones.

Superior Orbital Fissure

Between the lesser wing and greater wing; passage of first division of the CNV.

Inferior Orbital Fissure

Separates the lateral wall from the floor of the oral cavity.

Sphenoparietal Suture

Varies in length in different skulls, and is absent in those cases where the frontal articulates with the temporal squama.

Pterion

The point corresponding with the posterior end of the sphenoparietal suture.

Lambdoid Suture

Is continuous below with the occipitomastoid suture between the occipital and the mastoid portion of the temporal.

Mastoid Foramen

In or near the last suture; it is for the transmission of an emissary vein.

Superciliary Arch

Immediately above the orbital margin.

Parietal Eminence

Near the center of the parietal bone.

Temporal Lines

Arching across the side of the cranium, which marks the upper limit of the temporal fossa.

Pterygo-palatine Fossa

Pyramidal space situated at the angle between the pterygo-maxillary fissure and inferior orbital fissure.

Infratemporal Crest

Forms the vertical part of the greater wing meets the horizontal part of the greater wing.

Suprameatal Triangle

Triangular part above the external acoustic meatus.

Glenoid Fossa

Beside the articular tubercle; presented in norma basalis externa.

Styloid Process

Hook-like attachment for stylo ligament under the TMJ.

Supramastoid Crest

Once the temporal line reaches the mastoid bone; a point reference for dividing the squamous part and mastoid bone.

Squamous Part of Temporal Bone

Scale-like structure.

Articular Eminence

Stopper when we open the jaw.

External Oblique Line

Elevation from the body of mandible moving upward and backward towards the ramus of the mandible.

Mental Foramen

An opening below the apex of premolars; passage of the terminal branches of inferior alveolar nerve, a branch under the trigeminal nerve.

Gonion

Where the superior and anterior part of the mandible meets.

Coronoid Notch

Landmark used to identify the point of insertion when doing an inferior alveolar nerve block.

Sigmoid Notch

Indentation between coronoid and condyle process.

Pterion

Formed by the articulation of frontal bone, sphenoid, parietal, temporal.

Asterion

Formed at the junction of lambdoid suture and occipitomastoid suture, and parietomastoid suture.

Zygomatic Arch

Formed by the union of zygomatic process of temporal bone and temporal process of zygomatic bone.

Frontal Crest

Ridge; elevation in the midline; for attachment of meninges.

Foramen Cecum

At the base of frontal crest; opening; passage of emissary veins.

Orbital Plates of Frontal Bone

Forming the floor of the anterior cranial fossa from this view.

Olfactory Foramina

Opening for the passage of the CN II; Perforate the cribriform plate.

Cribriform Plate

Plate of bone where you find the opening.

Crista Galli

An extension of the perpendicular plate of ethmoid seen on the anterior aspect; resembles a cockscombs.

Jugum Sphemoidal

Located behind the cribriform plate.

Optic Canal

Seen from the internal aspect.

Anterior Clinoid Process

Prominent corners of the lesser wing.

Chiasmatic Groove

Canal between the optic canal; limited anteriorly by limbus sphenoidal.

Tuberculum Sella

Located between the hypophyseal fossa and optic groove.

Hypophyseal Fossa

Depression at the center of sella turcica; contains the pituitary gland.

Foramen Ovale

3rd division of trigeminal nerve passes the cranium; used by the mandibular division in getting out of the cranium.

Foramen Spinosum

Is used by nervous spinous.

Arcuate Eminence

Mountain-like.

Trigeminal Impression

Where the trigeminal nerve ganglion is located.

Tegment Tymphani

Roof of the middle ear; below the arcuate eminence.

Internal Acoustic Meatus

Used by the facial nerve in getting into the cranial cavity.

Cleavus

Slopping down from sella turcica.

Hypoglossal Canal

Passage for the hypoglossal nerve.

Internal Occipital Crest

Below the foramen magnum.

Foramen Lacerum

Regular opening bounded by temporal, sphenoid, occipital.

Jugular Foramen

Bounded by temporal, occipital.

Alveolar Process

Roots of upper teeth.

Incisive Canal

Cranial passage nasopalatine nervous carpa.

Greater Palatine Foramen

Formed by the maxilla and palatine bone.

Transverse Palatine Suture

Indicated the union between the maxillary and palatine bone.

Choanae

Refer to posterior opening of the nasal cavity.

Jugular Foramen

Formed between the temporal and occipital bone.