Axial Skeleton Bones, Markings, and Openings

Vocabulary flashcards covering the required bones, processes, markings, depressions, and openings of the axial skeleton.

Glabella

A smooth marking located on the frontal bone of the cranium above the nasion.

Supraorbital notch

A small notch or opening located on the superior margin of the orbit in the frontal cranial bone.

Coronal Suture

The suture marking that joins the frontal bone with the parietal bones.

Sagittal Suture

The suture marking situated between the two parietal bones along the midline of the skull.

External Acoustic Meatus

The ear canal opening located within the temporal cranial bone.

Carotid Foramen/Canal

A canal/opening in the temporal cranial bone that transmits the internal carotid artery.

Mandibular fossa

A depression on the inferior surface of the temporal bone that articulates with the condylar process of the mandible.

Mastoid Process

A prominent conical projection located on the inferior portion of the temporal cranial bone behind the ear.

Styloid Process (Temporal)

A slender, needle-like projection pointing downward from the inferior surface of the temporal cranial bone.

Zygomatic Process (Temporal)

A projection extending anteriorly from the squamous part of the temporal bone to articulate with the zygomatic bone.

Squamous Suture

The cranial suture between the temporal bone and the parietal bone.

Lambdoid Suture

The suture marking connecting the occipital bone with the parietal bones.

Foramen Magnum

The large opening in the base of the occipital bone through which the spinal cord passes.

Jugular Foramen

A large depression and opening located posterior to the carotid canal between the occipital and temporal bones.

Occipital Condyle

Rounded articular processes on the inferior surface of the occipital bone that articulate with the atlas ($C1$).

External Occipital Protuberance

A midline bony prominence on the posterior external surface of the occipital bone.

Sella Turcica

A saddle-shaped depression in the sphenoid bone that houses the pituitary gland.

Foramen Ovale

An oval-shaped opening in the greater wing of the sphenoid cranial bone.

Superior Orbital Fissure

A diagonal opening/fissure between the greater and lesser wings of the sphenoid bone into the orbit.

Optic Canal

An opening in the lesser wing of the sphenoid bone that transmits the optic nerve.

Pterygoid Process

Inferiorly projecting wing-like processes extending from the sphenoid bone.

Crista galli

A midline vertical ridge extending superiorly from the cribriform plate of the ethmoid cranial bone.

Cribriform plate

A horizontal, perforated bony plate of the ethmoid cranial bone through which olfactory nerve filaments pass.

Perpendicular Plate (Ethmoid)

A thin, vertical bony plate of the ethmoid bone that forms the superior part of the nasal septum.

Middle Nasal Concha

A curved, scroll-like medial process of the ethmoid cranial bone extending into the nasal cavity.

Intermaxillary suture

The suture process uniting the left and right maxillae along the midline of the face.

Infraorbital Foramen

An opening located on the anterior surface of each maxilla inferior to the orbit.

Incisive Fossa

A depression/opening located behind the incisor teeth on the anterior palatal surface of the maxillae.

Lacrimal fossa

A groove or depression formed in the lacrimal bone that houses the lacrimal sac.

Temporal Process (Zygomatic)

A process of the zygomatic bone that projects posteriorly to join the zygomatic process of the temporal bone.

Hard Palate

The bony roof of the mouth formed by the horizontal plates of the palatine bones and the palatine processes of the maxillae.

Condylar Process

The posterior process on the superior margin of the mandibular ramus that articulates with the temporal bone.

Coronoid Process (Mandible)

The anterior, pointed projection on the superior end of the mandibular ramus.

Mandibular Notch

The broad, curved depression between the coronoid process and condylar process of the mandible.

Mental Foramen

An opening on the anterolateral surface of the body of the mandible.

Mandibular Foramen

An opening on the medial surface of the mandibular ramus.

Alveolar Processes

The thickened arches of bone containing the sockets for the teeth in the mandible and maxillae.

Greater & Lesser Horns

Paired lateral projections extending from the body of the hyoid bone.

Atlas

The first cervical vertebra ($C1$), which articulates with the occipital condyles and lacks a vertebral body.

Axis

The second cervical vertebra ($C2$), characterized by an upward projection called the dens.

Dens

A tooth-like upward process on the axis ($C2$) vertebra that serves as a pivot point for cervical rotation.

Transverse foramen

Openings located within the transverse processes of cervical vertebrae for the passage of the vertebral artery and vein.

Costal Facet

Articular depression surfaces on the bodies and transverse processes of thoracic vertebrae for articulation with ribs.

Intervertebral Foramen

Lateral openings formed between adjacent pedicles of articulated vertebrae for spinal nerves.

Vertebral Foramen

The central opening bounded by the body and vertebral arch that contains the spinal cord.

Sacral Hiatus & Canal

The continuation and inferior termination opening of the vertebral canal within the sacrum.

Median Sacral Crest

A central ridge along the posterior midline of the sacrum formed by fused spinous processes.

Manubrium

The broad, superior portion of the sternum that articulates with the clavicles and first pair of ribs.

Xiphoid Process

The small, cartilaginous/bony inferior tip of the sternum.

Vertebrosternal Rib

A true rib (ribs $1$–$7$) that attaches directly to the sternum through its own costal cartilage.

Vertebrocostal Rib

A false rib (ribs $8$–$10$) whose costal cartilage attaches indirectly to the sternum by merging with the cartilage of the rib above.

Floating Rib

A rib (ribs $11$ and $12$) that has no anterior attachment to the sternum or costal cartilage.

Costal Groove

A longitudinal depression along the internal inferior border of a rib that accommodates intercostal nerves and blood vessels.