Master Anatomy Guide: Skull, Mandible, Cranial Fossae, Neck Triangles & Trigeminal Nerve (CN V)

Vocabulary flashcards covering skull anatomy, cranial base foramina, mandible structures, maxillofacial fractures, neck triangles, and trigeminal nerve components.

External Table

The outer compact bone layer of the cranium.

Diploë

The spongy bone layer situated between the external and internal tables of the skull, containing diploic veins.

Internal Table

The inner compact bone layer of the cranium, which is thinner and more brittle than the external table.

Coronal Suture

The junction suture between the frontal bone and parietal bones.

Sagittal Suture

The junction suture between the two parietal bones along the midline.

Lambdoid Suture

The junction suture between the parietal bones and the occipital bone.

Pterion

An H-shaped suture junction of frontal, parietal, greater wing of sphenoid, and squamous temporal bones, marking the thinnest part of the lateral skull wall and overlying the anterior division of the middle meningeal artery and vein.

Suprameatal Triangle (Macewen’s Triangle)

Surgical landmark bounded superiorly by the supramastoid crest, anteriorly by the postero-superior margin of the external auditory meatus, and posteriorly by a vertical tangent to the meatal margin, deep to which lies the mastoid antrum.

Anterior Fontanelle (Bregma)

Diamond-shaped space situated between two halves of the frontal bone and parietal bones; closes by 18 months.

Posterior Fontanelle (Lambda)

Triangular space situated between parietal bones and the occipital bone; closes by the end of the 1st year.

Supraorbital Foramen/Notch

An opening in norma frontalis that transmits the supraorbital nerve and vessels.

Infraorbital Foramen

An opening located below the lower orbital margin that transmits the infraorbital nerve and vessels.

Mental Foramen

An opening located below the second premolar tooth on the mandible that transmits the mental nerve and vessels.

Parietal Foramen

An opening located approximately 2.5 cm anterior to the lambdoid suture that transmits an emissary vein connecting scalp veins to the superior sagittal sinus.

Incisive Foramen

An opening in the hard palate that transmits nasopalatine nerves and greater palatine vessels.

Choanae (Posterior Nasal Apertures)

The posterior nasal openings separated in the midline by the vomer.

Cribriform Plate

An ethmoid bone structure in the anterior cranial fossa that transmits olfactory nerves (CN I).

Optic Canal

An opening in the lesser wing of the sphenoid that transmits the optic nerve (CN II) and ophthalmic artery.

Superior Orbital Fissure

An opening between the lesser and greater wings of the sphenoid transmitting CN III, CN IV, ophthalmic division of CN V (V1), CN VI, and ophthalmic veins.

Foramen Rotundum

An opening in the greater wing of the sphenoid that transmits the maxillary nerve (CN V2).

Foramen Ovale

An opening in the greater wing of the sphenoid that transmits the mandibular nerve (CN V3), motor root, lesser petrosal nerve, accessory meningeal artery, and emissary vein.

Foramen Spinosum

An opening in the greater wing of the sphenoid that transmits the middle meningeal artery and vein, and meningeal branch of CN V3.

Foramen Lacerum

An opening at the temporal and sphenoid junction over which the internal carotid artery passes.

Foramen Magnum

An occipital bone opening transmitting the apical ligament of dens, tectorial membrane, medulla oblongata, meninges, vertebral arteries, and spinal accessory nerve.

Hypoglossal Canal

An occipital bone opening that transmits the hypoglossal nerve (CN XII).

Jugular Foramen

An opening at the temporal/occipital junction transmitting the inferior petrosal sinus, CN IX, CN X, CN XI, and sigmoid sinus.

Internal Acoustic Meatus

An opening in the petrous part of the temporal bone transmitting the facial nerve (CN VII), vestibulocochlear nerve (CN VIII), and labyrinthine vessels.

Symphysis Menti

A faint midline ridge on the external surface of the body of the mandible indicating the line of fusion of the two halves.

Mental Spines (Genial Tubercles)

Projections on the internal surface of the mandibular body; superior spines give origin to genioglossus muscle, and inferior spines give origin to geniohyoid muscle.

Mylohyoid Line

An oblique ridge passing backward and upward on the internal surface of the body of the mandible, providing origin for the mylohyoid muscle.

Sublingual Fossa

A smooth area above the mylohyoid line for the sublingual gland.

Submandibular Fossa

A depressed area below the posterior part of the mylohyoid line for the submandibular gland.

Mandibular Foramen

An opening located on the medial aspect of the ramus of the mandible transmitting inferior alveolar nerve and vessels.

Lingula

A tongue-like projection covering the anterior border of the mandibular foramen that gives attachment to the sphenomandibular ligament.

Mylohyoid Groove

A groove extending inferoanteriorly from the mandibular foramen transmitting the mylohyoid nerve and vessels.

Coronoid Process

A pointed anterior projection on the ramus of the mandible receiving insertion of the temporalis muscle.

Condyloid Process

A posterior projection on the ramus of the mandible articulating at the temporomandibular joint (TMJ).

Pterygoid Fovea

A depression on the anterior aspect of the condylar neck of the mandible for the lateral pterygoid muscle insertion.

Battle's Sign

Bruising over the mastoid process appearing days after injury, indicative of a posterior cranial fossa fracture.

Le Fort I (Horizontal Maxillary Fracture)

Separation of the alveolar process of the maxilla from the upper facial skeleton along the nasal floor.

Le Fort II (Pyramidal Fracture)

A maxillofacial fracture passing through nasal bones, lacrimal bones, orbital floor, and inferior orbital margin.

Le Fort III (Transverse Facial / Craniofacial Dysjunction)

A fracture line extending across the bridge of the nose, orbital wall, zygomatic arch, and pterygoid plates, completely separating the face from the skull base.

Submental Triangle

An unpaired anterior neck triangle bounded by the hyoid bone and right/left anterior bellies of digastric muscles; contains submental lymph nodes.

Submandibular (Digastric) Triangle

An anterior neck triangle bounded by the mandible base, anterior digastric belly, and posterior digastric belly; contains submandibular gland, facial artery/vein, and hypoglossal nerve (CN XII).

Carotid Triangle

An anterior neck triangle bounded by anterior SCM, superior belly of omohyoid, and posterior digastric; contains carotid sheath and hypoglossal nerve (CN XII).

Muscular Triangle

An anterior neck triangle bounded by the midline, superior belly of omohyoid, and inferior SCM; contains infrahyoid strap muscles, thyroid gland, larynx, and trachea.

Occipital Triangle

A posterior neck triangle subdivision bounded by SCM, trapezius, and inferior belly of omohyoid; contains spinal accessory nerve (CN XI).

Supraclavicular (Subclavian) Triangle

A posterior neck triangle subdivision bounded by inferior belly of omohyoid, clavicle, and SCM; contains third part of subclavian artery, subclavian vein, and trunks of brachial plexus.

Mesencephalic Nucleus

Trigeminal sensory nucleus located in midbrain containing primary sensory neurons mediating proprioceptive inputs from masticatory muscles, TMJ, and periodontal ligaments.

Principal (Main) Sensory Nuclei

Trigeminal sensory nucleus in pons mediating fine tactile discrimination and pressure sensation.

Spinal Nucleus of Trigeminal Nerve

Trigeminal sensory nucleus extending from pons to C2/C3 cervical cord, mediating pain and temperature sensation.

Meckel's Cave

A dural recess containing the trigeminal ganglion situated over the petrous temporal apex.

Trigeminal Neuralgia (Tic Douloureux)

A condition marked by paroxysmal episodes of intense, sharp, lancinating facial pain typically along V2 or V3 distributions.