Parts of the Skull

What bones touch at the Lambdoidal suture?

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What bones touch at the Sagittal suture?

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What bones touch at the Squamous suture?

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Where is the groove for the superior sagittal sinus?

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Where are the Mastoid Sinuses?

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What bones of the skull do not touch the sphenoid bone?

?????????????????????????????????? 3. Ossicle Bones (Malleus, Incus, Stapes) 4. Nasal Bones 5. Lacrimal Bones 6. Inferior Nasal Concha Bones 7. Mandible

What are the components of TMJ?

??????????????????????????????????? The temporomandibular joint (TMJ) is an atypical synovial joint located between the condylar process of the mandible and the mandibular fossa and articular eminence of the temporal bone. It is divided into superior discotemporal space and inferior dicomandibular space by the TMJ disc (or meniscus). The joint is surrounded by a capsule which is attached inferiorly to the head of the condyle (above the pterygoid fovea - attachment of the inferior belly of the lateral pterygoid muscle) and superiorly to the margins of the mandibular fossa (posteriorly) and articular eminence (anteriorly) of the temporal bone.

How does a branch of V3 travel through the mandibular foramen and out the mental foramen?

???????????????????????????????????? Is Dr. G referring to the Mandibular Canal?????? The mandibular canal is a canal within the mandible that contains the inferior alveolar nerve, inferior alveolar artery, and inferior alveolar vein. It runs obliquely downward and forward in the ramus, and then horizontally forward in the body, where it is placed under the alveoli and communicates with them by small openings. It is continuous with the mental foramen (which opens onto front of mandible) and mandibular foramen (on medial aspect of ramus).

Where is the groove for the transverse sinus?

Along the internal surface of the occipital bone, running laterally between superior and inferior fossae of the cruciate eminence is the groove for the transverse sinus. The transverse sinuses travel along this groove.

Where is the Jugum?

In the first year after birth the great wings and body unite, and the small wings extend inward above the anterior part of the body, and, meeting with each other in the middle line, form an elevated smooth surface, termed the jugum

What is the posterolateral fontanel of the fetal skull?

Mastoid fontanel

Where is the External Occipital Protuberance?

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

What is the first fontanel to close?

Occipital

What is the posterior fontanel of the fetal skull?

Occipital fontanel

Where is the Alveolar Process?

On the mandible, it is a ridge on the superior surface.

What does the Sphenoidal fontanel become in the adult?

Pterion

What is the anterolateral fontanel of the fetal skull?

Sphenoidal fontanel

List the four divisions of the temporal bone.

Squamous, Mastoid, Tympanic and Petrous

Where is the External Occipital Crest?

The External occipital crest is part of the external surface of the Squama occipitalis of the occipital bone. It is a ridge travels along the midline, beginning at the external occipital protuberance and descending inferiorly to the foramen magnum

What bones does the Occipital bone lie between?

The Occipital Bone lies between the Parietal and Temporal bones on both sides.

Where is the Orbital Plate?

The Orbital Plate of the Ethmoid Bone is a smooth, oblong bone plate which forms the lateral surface of the labyrinth of the ethmoid bone in the skull. The plate covers in the middle and posterior ethmoidal cells and forms a large part of the medial wall of the orbit. It articulates above with the orbital plate of the frontal bone, below with the maxilla and the orbital process of palatine bone, in front with the lacrimal, and behind with the sphenoid. This part of the ethmoid bone is paper-thin and fractures easily.

What bones make up the pterion? What is the pterion also called?

The Pterion is the intersection of the Parietal, Frontal, Temporal, and Sphenoid Bones. The Pterion is also called the temple.

What bones does the temporal bone lie between?

The Sphenoid, Parietal and Occipital bones

Where are the Anterior Clinoid Processes?

The anterior and posterior clinoid processes surround the sella turcica like the four corners of a four poster bed.

What does the Squamous suture connect?

The asterion to the pterion.

Where are the Superior Nasal Conchae?

The back part of the medial surface of the labyrinth of ethmoid is subdivided by a narrow oblique fissure, the superior meatus of the nose, bounded above by a thin, curved plate, the superior nasal concha. The bone found in superior nasal concha is part of the ethmoid bone.

Where is the Frontal Bone?

The border of the squama frontalis is thick, strongly serrated, bevelled at the expense of the inner table above, where it rests upon the parietal bones, and at the expense of the outer table on either side, where it receives the lateral pressure of those bones; this border is continued below into a triangular, rough surface, which articulates with the great wing of the sphenoid. The posterior borders of the orbital plates are thin and serrated, and articulate with the small wings of the sphenoid.

Where is the Bregma?

The bregma is located at the intersection of the coronal suture and the sagittal suture on the superior middle portion of the calvaria. It is the point where the frontal bone and parietal bones meet. The bregma is known as the anterior fontanelle during infancy.

What does the Sagittal suture connect?

The bregma to the lambda.

Where is the Carotid Canal?

The carotid canal is the passage way in the temporal bone through which the internal carotid artery enters the middle cranial fossa from the neck. The canal starts on the inferior surface of the temporal bone at the external opening of the carotid canal (also referred to as the carotid foramen). The canal ascends at first vertically, and then, making a bend, runs horizontally forward and medialward. The canal's internal opening is near the foramen lacerum above which the internal carotid artery passes on its way to the cavernous sinus.

Where is the Clivus?

The clivus (Latin for "slope") is a part of the cranium, a shallow depression behind the dorsum sellæ that slopes obliquely backward. It forms a gradual sloping process at the anterior most portion of the basilar occipital bone at its junction with the sphenoid bone. The clivus is an important landmark for checking for anatomical atlanto-occipital alignment

What does the Mastoid fontanel become in the adult?

Asterion

Where are the parietal foramina?

At the back part of the parietal bone and close to the upper or sagittal border is the parietal foramen, which transmits the parietal emissary vein which anastamoses with the superior sagittal sinus, and sometimes a small branch of the occipital artery; it is not constantly present, and its size varies considerably.

Where is the Stylomastoid Foramen? What nerve travels through it?

Between the styloid and mastoid processes of the temporal bone is the stylomastoid foramen. It is the termination of the facial canal, and transmits the facial nerve and stylomastoid artery.

Where is the Cribriform Plate?

The cribriform plate of the ethmoid bone is received into the ethmoidal notch of the frontal bone and roofs in the nasal cavities. Projecting upward from the middle line of this plate is a thick, smooth, triangular process, the crista galli, so called from its resemblance to a rooster's comb. The long thin posterior border of the crista galli serves for the attachment of the falx cerebri. Its anterior border, short and thick, articulates with the frontal bone, and presents two small projecting alae (wings), which are received into corresponding depressions in the frontal bone and complete the foramen cecum.

Where is the Crista Galli? What attaches here?

The crista galli (Latin: "crest of the cock") is a median ridge of bone that projects from the cribriform plate of the ethmoid bone. It is where the falx cerebri attaches anteriorly to the skull. The falx cerebri is a strong, arched fold of dura mater that descends vertically in the longitudinal fissure, forming the lateral cerebral hemispheres. It is narrow in front, where it is attached to the crista galli of the ethmoid; and broad behind, where it is connected with the upper surface of the tentorium cerebelli.

What bones does the Ethmoid Bone lie between?

The ethmoid articulates with fifteen bones: four of the neurocranium—the frontal, and the sphenoid (at the sphenoidal body and at the sphenoidal conchae). eleven of the viscerocranium—, two Nasal bones, two maxillae, two lacrimals, two palatines, two inferior nasal conchae, and the vomer

Where is the Ethmoid Bone?

The ethmoid bone is a cubical bone in the skull that separates the nasal cavity from the brain. It is located at the roof of the nose, between the two orbits. The ethmoid has three parts: the cribriform plate, the ethmoidal labyrinth, and the perpendicular plate.

What is the frontal squama?

The exterior sufrace of the frontal bone. The location of the forehead.

Where are the Sphenoidal Sinus? What nerves pass through it?

When exceptionally large they may extend into the roots of the pterygoid processes or great wings, and may invade the basilar part of the occipital bone. Each sinus opens into the roof of the nasal cavity via apertures on the posterior wall of the sphenoethmoidal recess directly above the choana. The apertures are located high on the anterior walls of the sinuses themselves. The mucous membrane receives sensory innervation by the posterior ethmoidal nerves, and postganglionic parasympathetic fibers of the facial nerve that synapsed at the pterygopalatine ganglion which control secretion of mucous.

Where is the Zygomatic Process of the Temporal Bone?

Zygomatic process is a protrusion from the rest of the skull, like the bumper of a car. Most of it belongs to the zygomatic bone, and could therefore be called the zygomatic process of the zygomatic bone. However, there are other bones contributing to it too, namely the frontal bone, maxilla and temporal bone, which therefore form: Zygomatic process of frontal bone Zygomatic process of maxilla Zygomatic process of temporal bone

Where is the Superior Nuchal Line?

The nuchal lines are curved lines on the external surface of the occipital bone.

Where are the occipital condyles?

The occipital condyles are undersurface facets of the occipital bone in vertebrates, which function in articulation with the superior facets of the atlas vertebra. The condyles are oval or reniform (kidney-shaped) in shape, and their anterior extremities, directed forward and medialward, are closer together than their posterior, and encroach on the basilar portion of the bone; the posterior extremities extend back to the level of the middle of the foramen magnum.

Where is the Optic Canal (Foramen)?

The optic foramen is the opening to the optic canal. The superior surface of the sphenoid bone is bounded behind by a ridge, which forms the anterior border of a narrow, transverse groove, the chiasmatic groove (optic groove), above and behind which lies the optic chiasma; the groove ends on either side in the optic foramen, which transmits the optic nerve and ophthalmic artery (with accompanying sympathetic nerve fibres) into the orbital cavity.

Where are the Bones for the Middle Ear (From Lateral to Medial)?

The ossicles (also called auditory ossicles) are three bones in either middle ear that are among the smallest bones in the human body. The ossicles are, in order from the eardrum to the inner ear (from superficial to deep): the malleus, incus, and stapes. Terms that, in Latin, are translated as the hammer, the anvil, and the stirrup. The malleus (#1) (hammer) articulates with the incus through the incudomalleolar joint and is attached to the tympanic membrane (eardrum), from which vibrational sound pressure motion is passed. The incus (#2) (anvil) is connected to both the other bones. The stapes (#3) (stirrup) articulates with the incus through the incudostapedial joint and is attached to the membrane of the fenestra ovalis, the elliptical or oval window or opening between the middle ear and the vestibule of the inner ear. It is the smallest bone in the body.

Where is the Median Perpendicular Plate?

The perpendicular plate of the ethmoid bone (vertical plate) is a thin, flattened lamina, polygonal in form, which descends from the under surface of the cribriform plate, and assists in forming the septum of the nose; it is generally deflected a little to one or other side. The anterior border articulates with the spine of the frontal bone and the crest of the nasal bones. The posterior border articulates by its upper half with the sphenoidal crest, by its lower with the vomer.

What does the Coronal suture connect?

The pterion to the bregma.

What does the Frontal fontanel become in the adult?

Bregma

Where is the Groove for the sigmoid sinus?

Groove for Sigmoid Sinus is a groove in the posterior cranial fossa.

Where are the temporal lines?

Crossing the middle of the parietal bone in an arched direction are two very close curved lines, the superior and inferior temporal lines.

What are the four parts of the Sella Turcica?

Hypophyseal Fossa, Tuberculum Sellae, Dorsum Sellae, Posterior Clinoid Process

Where are the Pterygoid Processes?

The pterygoid processes of the sphenoid, one on either side, descend perpendicularly from the regions where the body and great wings (alisphenoid) unite.

What is the final fontanel to close?

Frontal

What bones touch at the Coronal suture?

Frontal and Parietal

What is the anterior fontanel of the fetal skull?

Frontal fontanel

Where is the Tuberculum Sellae?

In the sphenoid bone, behind the chiasmatic groove is an elevation, the tuberculum sellae (or the tubercle of sella turcica). A variable slight to prominent median elevation forming the posterior boundary of the prechiasmatic sulcus and the anterior boundary of the hypophysial fossa.

Where is the Hypophyseal Fossa?

In the sphenoid bone, behind the chiasmatic groove is an elevation, the tuberculum sellae; and still more posteriorly, a deep depression or fossa, the sella turcica, the deepest part of which lodges the pituitary gland (hypophysis), and is also known as the hypophysial fossa.

Where are the Posterior Clinoid Processes?

In the sphenoid bone, the anterior boundary of the sella turcica is completed by two small eminences, one on either side, called the anterior clinoid processes, while the posterior boundary is formed by a square-shaped plate of bone, the dorsum sellæ, ending at its superior angles in two tubercles, the posterior clinoid processes, the size and form of which vary considerably in different individuals. The posterior clinoid processes deepen the sella turcica, and give attachment to the tentorium cerebelli.

Where is the Dorsum Sellae?

In the sphenoid bone, the anterior boundary of the sella turcica is completed by two small eminences, one on either side, called the middle clinoid processes, while the posterior boundary is formed by a square-shaped plate of bone, the dorsum sellae, ending at its superior angles in two tubercles, the posterior clinoid processes, the size and form of which vary considerably in different individuals.

What are the three parts of the Sphenoid Bone body?

Jugum, Chiasmatic Groove, Groove for the internal carotid artery

What does the Occipital fontanel become in the adult?

Lambda

Where is the Foramen Magnum?

The foramen magnum (Latin: "great hole") is a large opening in the occipital bone of the cranium.

Where is the Foramen Ovale? What nerves passes through it?

The foramen ovale is a foramen in the greater wing of the sphenoid bone. The foramen ovale is one of two cranial foramina in the greater wing, the other being the foramen spinosum. The foramen ovale is posterolateral to the foramen rotundum and anteromedial to the foramen spinosum. Posterior and medial to the foramen is the opening for the carotid canal. The two nerves that pass through it are: Mandibular nerve, the third branch of the trigeminal nerve. Lesser petrosal nerve, a branch of the glossopharyngeal nerve.

Where is the Foramen Rotundum? What nerve passes through it?

The foramen rotundum is a circular hole in the sphenoid bone that connects the middle cranial fossa and the pterygopalatine fossa. The maxillary nerve passes through and exits the skull via the pterygopalatine fossa and the foramen rotundum.

Where is the Foramen Spinosum? What two nerves pass through it?

The foramen spinosum is one of two foramina located in the base of the human skull, on the sphenoid bone. It is situated just anterior to the spine of the sphenoid bone, and just lateral to the foramen ovale. The meningeal branch of the mandibular nerve pass through this foramen.

Where is the Glabella?

The glabella is the space between the eyebrows and above the nose. It is slightly depressed, and joins the two superciliary ridges.

Where is the Greater Wing of the Sphenoid Bone?

The greater wing of the sphenoid bone is a bony process of the sphenoid bone; there is one on each side, extending from the side of the body of the sphenoid and curving upward, laterally, and backwards.

Where is the hypoglossal canal? What nerve travels through it?

The hypoglossal canal is a bony canal in the occipital bone of the skull. It transmits the hypoglossal nerve from its point of entry near the medulla oblongata to its exit from the base of the skull near the jugular foramen. It lies in the epiphyseal junction between the basiocciput and the jugular process of the occipital bone.

What is the inion?

The inion is the most prominent projection of the occipital bone at the posterioinferior (lower rear) part of the skull. The term external occipital protuberance (protuberantia occipitalis externa) is sometimes used as a synonym, but more precisely the term "inion" refers to the highest point of the external occipital protuberance.

Where is the jugular foramen? What bones form it? What nerves pass through it? What depression is next to it?

The jugular foramen is a large aperture in the base of the skull. It is located behind the carotid canal. Two bones form the jugular foramen - it is formed in front by the petrous portion of the temporal bone, and behind by the occipital bone. The jugular foramen transmits the glossopharyngeal, vagus, and accessory nerves (aka cranial nerves number IX, X, and XI respectively). The jugular fossa is a deep depression located lateral to the jugular foramen.

What does the Lambdoidal suture connect?

The lambda to the asterion.

Where are the Lateral Pterygoid Plates?

The lateral pterygoid plate of the sphenoid (or lateral lamina of pterygoid process) is broad, thin, and everted; its lateral surface forms part of the medial wall of the infratemporal fossa, and gives attachment to the lateral pterygoid muscle; its medial surface forms part of the pterygoid fossa, and gives attachment to the medial pterygoid muscle.

Where are the Lesser Wings of the Sphenoid Bone?

The lesser wings of the sphenoid are two thin triangular plates, which arise from the upper and anterior parts of the body, and, projecting lateralward, end in sharp points.

Where is the External Acoustic Meatus?

The location of the ear canal.

Where is the Mandible? With which bones does it articulate?

The mandible consists of: - body of mandible - two perpendicular parts, the rami, or ramus for each one, unite with the ends of the body nearly at right angles. - The angle formed at this junction is called gonial angle. - Alveolar process, the tooth bearing area of the mandible - Condyle, superior (upper) and posterior projection from the ramus, which makes the temporomandibular joint with the temporal bone - Coronoid process, superior and anterior projection from the ramus. This provides attachment to the temporalis muscle The mandible articulates with the two temporal bones at the temporomandibular joints.

Where is the Mandibular Fossa?

The mandibular fossa is the depression in the temporal bone that articulates with the mandibular condyle.

Where is the Mastoid Process?

The mastoid process is a conical prominence projecting from the undersurface of the mastoid portion of the temporal bone. It is located just behind the external acoustic meatus, and lateral to the styloid process. Its size and form vary somewhat; it is larger in the male than in the female.

Where are the Medial Pterygoid Plates?

The medial pterygoid plate (or medial pterygoid lamina) of the sphenoid is narrower and longer than the lateral pterygoid plate; it curves lateralward at its lower extremity into a hook-like process, the pterygoid hamulus, around which the tendon of the Tensor veli palatini glides.

Where are the Middle Nasal Conchae?

The medial surface of the labyrinth of ethmoid consists of a thin lamella, which descends from the under surface of the cribriform plate, and ends below in a free, convoluted margin, the middle nasal concha. It is rough, and marked above by numerous grooves, directed nearly vertically downward from the cribriform plate; they lodge branches of the olfactory nerves, which are distributed to the mucous membrane covering the superior nasal concha.

Where is the Inferior Nuchal Line?

The nuchal lines are curved lines on the external surface of the occipital bone.

Where is the Sphenoid Bone? What bones does it lie between?

The sphenoid bone is an unpaired cranial bone situated at the front middle of the skull in front of the temporal bone and basilar part of the occipital bone. Its shape somewhat resembles that of a butterfly or bat with its wings extended.

Where is the Styloid Process?

The styloid process is a slender pointed piece of bone just below the ear. It projects down and forward from the inferior surface of the temporal bone, and serves as an anchor point for several muscles associated with the tongue and larynx.

Where is the Superior Orbital Fissure?

The superior orbital fissure is a foramen in the skull, although strictly it is more of a cleft, lying between the lesser and greater wings of the sphenoid bone.

Where is the Chiasmatic Groove?

The superior surface of the body of the sphenoid bone is bounded behind by a ridge, which forms the anterior border of a narrow, transverse groove, the chiasmatic groove. The groove ends on either side in the optic foramen, which transmits the optic nerve and ophthalmic artery into the orbital cavity.

Where is the Supraciliary ridge?

The supraciliary ridge is a depressed line between the frontal squama and the supraorbital arch.

Where is the Supraorbital arch? What is its purpose?

The supraorbital arch is a nodule or crest of bone situated on the frontal bone of the skull, forming the separation between the supraciliary ridge and the roof of the eye sockets (the pars orbitalis). The ridges arch over each eye, offering mechanical protection.

Where is the Supraorbital foramen? What nerve travels through it?

The supraorbital foramen is a bony elongated path located above the orbit (eye socket) and under the forehead. The supraorbital foramen lies directly under the eyebrow. The supraorbital foramen arches transversely below the superciliary arches and is the upper part of the margin of the orbit, thin and prominent in its lateral two-thirds, rounded in its medial third, and presenting, at the junction of these two portions, the supraorbital notch or foramen for the supraorbital nerve and vessels (supraorbital artery and supraorbital vein.)

Where is the temporal bone?

The temporal bones are situated at the sides and base of the skull.