Anatomy of the Skull - Lecture 1

Vocabulary flashcards covering the cranial and facial bones, sutures, surface features, mandible landmarks, and cranial base foramina from Skull Anatomy Lecture 1.

Cranium

The skeletal structure of the head excluding the mandible.

Cranial Vault

The upper dome-like portion or roof of the cranium.

Base of the Skull

The lowest floor portion of the cranium upon which the brain rests.

Sutural Ligament

The connective tissue located between adjacent bones of the skull at immobile joints called sutures.

Bregma

The midline junction where the frontal bone articulates with the parietal bones along the coronal suture; represents the site of the anterior fontanelle.

Anterior Fontanelle

The diamond-shaped membranous space at the bregma in an infant skull that normally ossifies by 18 months of age.

Lambda

The midline point where the sagittal suture meets the lambdoid suture between the parietal bones and the squamous occipital bone; remnant of the posterior fontanelle.

External Occipital Protuberance

A midline bony prominence on the occipital bone located approximately $6\,\text{cm}$ below the lambda, from which a ridge curves convex upwards toward the mastoid process.

Pterion

An H-shaped sutural junction within the temporal fossa formed by the articulation of the frontal, parietal, temporal, and greater wing of the sphenoid bones, located $3\,\text{to}\,4\,\text{cm}$ superior to the zygomatic arch.

Extradural Bleeding

Hemorrhage occurring between the skull and dura mater, frequently caused by a fracture at the pterion damaging the underlying middle meningeal artery.

Symphysis Menti

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

Mental Foramen

An opening on the lateral aspect of the mandibular body below the second premolar tooth that transmits the mental nerve and vessels.

Mylohyoid Line

An oblique bony ridge along the internal surface of the mandible that serves as the attachment site for the mylohyoid muscle.

Submandibular Fossa

A shallow depression on the internal surface of the mandible located below the posterior part of the mylohyoid line, lodging the superficial part of the submandibular salivary gland.

Sublingual Fossa

A depression on the internal surface of the mandible situated above the anterior part of the mylohyoid line, accommodating the sublingual gland.

Lingula

A small bony projection anterior to the mandibular foramen on the medial surface of the ramus, providing attachment for the sphenomandibular ligament.

Mandibular Canal

A bony canal extending from the mandibular foramen on the medial surface of the ramus to the mental foramen on the lateral surface of the mandibular body.

Granular Pits (Granular Foveolae)

Small depressions located alongside the sagittal groove on the internal surface of the cranial vault that lodge lateral lacunae and arachnoid granulations.

Crista Galli

A sharp midline upward projection of the ethmoid bone in the anterior cranial fossa that anchors the falx cerebri.

Anterior Cranial Fossa

The cranial compartment lodging the frontal lobes of the cerebral hemispheres, bounded anteriorly by the frontal bone and posteriorly by the lesser wings of the sphenoid.

Sella Turcica

A saddle-shaped depression in the central body of the sphenoid bone within the middle cranial fossa that contains the pituitary gland.

Dorsum Sellae

A square plate of bone forming the posterior boundary of the sella turcica, bearing the posterior clinoid processes at its superior lateral angles.

Optic Canal

A canal in the lesser wing of the sphenoid that transmits the optic nerve and ophthalmic artery.

Superior Orbital Fissure

A slitlike opening between the greater and lesser wings of the sphenoid transmitting the lacrimal, frontal, trochlear, oculomotor, nasociliary, and abducent nerves, as well as the superior ophthalmic vein.

Foramen Rotundum

An aperture in the greater wing of the sphenoid located behind the medial end of the superior orbital fissure that transmits the maxillary nerve.

Foramen Ovale

An opening in the greater wing of the sphenoid that transmits the mandibular nerve and the lesser petrosal nerve.

Foramen Spinosum

A small circular opening in the greater wing of the sphenoid posterolateral to the foramen ovale that transmits the middle meningeal artery.

Foramen Lacerum

A large, irregular opening between the petrous part of the temporal bone and the sphenoid bone through which the internal carotid artery enters via the carotid canal.

Foramen Magnum

The large opening in the occipital bone that transmits the medulla oblongata, surrounding meninges, spinal accessory nerve roots, and the vertebral arteries.

Hypoglossal Canal

A canal situated above the anterolateral border of the foramen magnum in the occipital bone that transmits the hypoglossal nerve (cranial nerve XII).

Jugular Foramen

An opening between the petrous temporal bone and the condylar part of the occipital bone transmitting cranial nerves IX, X, and XI, where the sigmoid sinus becomes the internal jugular vein.

Internal Acoustic Meatus

A canal in the petrous temporal bone transmitting the facial nerve (cranial nerve VII) and the vestibulocochlear nerve (cranial nerve VIII).