Anatomical Features of the Skull: Definitions and Examples

Vocabulary flashcards defining key anatomical terms and features of the skull along with specific bone examples.

Protuberance

A rounded projection or swelling on a bone. Examples: External occipital protuberance (occipital bone); Mental protuberance (mandible).

Ridge / Crest

A prominent narrow elongated elevation. Examples: Superior & inferior temporal lines (parietal bone); Median palatine crest (maxilla).

Fossa

A depression or hollow in a bone. Examples: Hypophyseal fossa (sphenoid bone); Mandibular fossa (temporal bone, TMJ); Lacrimal fossa (frontal bone).

Groove / Sulcus

A shallow furrow for vessels, nerves, or tendons. Examples: Groove for middle meningeal artery (parietal bone); Infraorbital groove (maxilla).

Foramen

A hole or opening in a bone for nerves or vessels. Examples: Foramen magnum (occipital bone); Supraorbital foramen (frontal bone); Mental foramen (mandible).

Canal

A tubular passage through a bone. Examples: Optic canal (sphenoid bone); Hypoglossal canal (occipital bone).

Process

A projection or outgrowth of bone. Examples: Mastoid process (temporal bone); Styloid process (temporal bone); Coronoid process (mandible).

Squamous (part)

Thin, flat portion of a bone. Example: Squamous part of temporal bone.

Tubercle / Nodule

A small rounded projection. Example: Articular tubercle (temporal bone, anterior to mandibular fossa; prevents anterior dislocation of TMJ condyle).

Nuchal Line

Curved lines for muscle attachment on the occipital bone. Examples: Superior nuchal line; Inferior nuchal line.

Fissure

A slit-like opening. Examples: Superior orbital fissure (sphenoid bone); Inferior orbital fissure (between maxilla and sphenoid).

Meatus

A canal-like passage. Examples: External acoustic meatus (temporal bone); Internal acoustic meatus (temporal bone).

Eminence

A raised area, larger than a tubercle but less sharp than a process. Examples: Frontal eminence (frontal bone); Parietal eminence (parietal bone).

Notch

An indentation at the edge of a bone. Examples: Supraorbital notch (frontal bone); Mandibular notch (between condylar & coronoid processes; passage for masseteric nerve/vessels).

Body

The main central portion of a bone. Examples: Body of mandible; Body of sphenoid bone.

Head

A rounded articular projection supported by a neck. Example: Head of mandible (condylar process).

Condyle

A large, smooth, rounded articular surface. Example: Occipital condyles (occipital bone, articulate with atlas).

Spine

A sharp, slender projection. Example: Spine of sphenoid (near foramen spinosum).

Alveolus (plural: alveoli)

Socket in the jaw for teeth. Examples: Alveolar processes of maxilla and mandible.

Lamina

A thin plate or layer of bone. Examples: Perpendicular plate of ethmoid; Cribriform plate of ethmoid.

Septum

A thin wall separating two cavities. Example: Nasal septum (vomer + perpendicular plate of ethmoid).

Sinus

An air-filled cavity within a bone. Examples: Maxillary sinus; Frontal sinus; Sphenoidal sinus.

Facet

Small, smooth, flat articular surface. Example: Articular facets on occipital condyles.

Linea (line)

A slight, elongated ridge. Examples: Inferior temporal line (parietal bone); Mylohyoid line (mandible).