Axial Skeleton - BYU Anatomy

Frontal bone

bone that forms the forehead

supraorbital notch

paired opening or notch superior to the orbit

superciliary arch

the ridge above the eye socket indicating the location of the frontal sinus

parietal bone

large paired bone located in the superior portion of the skull

coronal suture

runs laterally joining the frontal and parietal bones

sagittal suture

runs anteroposteriorly joining the temporal and parietal bones

temporal bone

paired bone located on the lateral sides of the skull

squamous suture

runs anteroposteriorly joining the temporal and parietal bones

mandibular fossa

articulates with the condylar process of the mandible

external auditory canal

opening in the temporal bone extending to the inner ear

petrous part

dense bony ridge on interior surface of temporal bone, location of middle and inner ear cavities

internal auditory canal

short canal in petrous part of temporal bone, extending laterally towards the inner ear.

styloid process

long sharp process of the temporal bone extending inferiorly

mastoid process

rounded process of the temporal bone posterior to the styloid process and extending inferiorly.

stylomastoid foramen

located between the styloid and mastoid processes; passageway for facial nerve

carotid canal

located on petrous part of the temporal bone anterior to the jugular foramen

jugular foramen

located on inferior petrous part of the temporal bone posterior to the carotid canal

occipital bone

most posterior and inferior bone of the skull

lambdoid suture

runs transversely joining the occipital and parietal bones

external occipital protuberance

median protrusion on the occipital bone posterior and superior to foramen magnum

foramen magnum

large opening on the inferior part of the skull

occipital condyle

paired rounded process lateral to the foramen magnum

hypoglossal canal

paired canal superior to occipital condyle

basilar part

region of the occipital bone anterior to foramen magnum

sphenoid bone

butterfly-shaped bone forming the floor of the cranium

greater wing

posterior and inferior to lesser wing on the interior of the skull, also visible in the posterior orbit and lateral side of the skull

lesser wing

anterior and superior to greater wing on the interior of the skull

superior orbital fissure

fissure between greater and lesser wings of sphenoid visible from the orbits

Inferior orbital fissure

fissure in the orbit floor between maxilla and greater wing of sphenoid

sella turcica

saddle-like depression posterior to lesser wing

optic canal

paired opening lateral to the sella turcica

foramen lacerum

paired opening lateral to the sella turcica

foramen ovale

paired opening lateral to the base of the sella turcica

foramen spinosum

paired opening at the posterior margin of the sphenoid

foramen rotundum

paired opening anterior to the foramen ovale

lateral pterygoid plate

sharp process that laterally and inferiorly projects from the sphenoid

medial pterygoid plate

sharp process that medially and inferiorly projects from the sphenoid

ethmoid bone

located between the orbits and between sphenoid and nasal bones; forms roof of nasal cavity

cribriform plate

porous bone surrounding the crista galli in the floor of the cranium through which olfactory nerves transverse

crista galli

superior projection in the middle of the cribriform plate of the ethmoid bone

perpendicular plate

median inferior projection of the ethmoid; forms superior nasal septum

vomer

bone forming the inferior and posterior portion of the nasal septum

inferior nasal concha

paired bone that protrudes into the inferior part of the nasal cavity

maxilla

paired fused bone of the upper jaw and central face

infraorbital foramen

paired opening inferior to the orbit

palatine process

anterior portion of the hard palate

palatine bone

situated at the back part of the nasal cavity between the maxilla and sphenoid bones

nasal bone

paired bone composing the superior portion (bridge) of the nose

lacrimal bone

paired bone forming part of the medial wall of the orbit

zygomatic bone

paired bone which forms the prominence of the cheek

zygomatic arch

formed by union of the zygomatic bone and the temporal bone

frontal sinus

cavity within the frontal bone
(purple in image)

sphenoidal sinus

paired cavity located within the sphenoid, inferior to the sella turcica

ethmoidal sinus

numerous cavities within the ethmoid bone

maxillary sinus

paired cavity found within the maxilla

mandible

lower jaw bone

body

most anterior part extending horizontally to the angle of the mandible

angle

where the body and ramus of the mandible meet

ramus

the verticle portion of the mandible extending from the angle

coronoid process

anterior process of the ramus

condylar process

The most posterior process of the ramus

mandibular notch

separates the coronoid from the condylar process

mandibular foramen

paired opening on the medial surface of the ramus

mental foramen

paired opening on the anterior aspect of the body

hyoid bone

U-shaped bone in the neck superior to the larynx

intervertebral discs

fibrocartilage cushion between the vertebral bodies

vertebra

basic bone unit of the vertebral column; all types of vertebrae (cervical, thoracic, and lumbar)

body

anterior portion of the vertebra

vertebral foramen

opening posterior to vertebral body through which the spinal cord passes

pedicle

posterior projection from vertebral body that supports the lamina

transverse process

lateral projections of the vertebra for muscle/ligament attachment

lamina

paired arches supported by the pedicles located posterior to the vertebral body

spinous process

most posterior projection of the vertebra for muscle/ligament attachment

superior articular process

paired (superior and inferior) process which articulates with process of adjacent vertebrae

superior articular facet

smooth surface of articular processes; superior and inferior

cervical vertebrae

transverse foramen

Atlas

(C1) supports the head

axis

(C2) serves as pivotal point for atlas and skull

dens

process of the axis which passes through the vertebral foramen of the atlas

thoracic vertebrae

12 total (T 1-T 12), vertebrae with circular vertebral foramen and long spinous process

costal facet

depression on transverse process; articulates with the tubercle of the ribs; also named transverse facet of thoracic vertebra in APR

costal demifacet

half facet on superior and inferior edges of each vertebral body; articulates with head of ribs; also named superior and inferior costal facet of thoracic vertebra in APR

lumbar vertebrae

5 total (L 1 - L 5), vertebrae with strongly built components for weight bearing

sacrum

(S1 - S5), composed of 5 fused vertebrae forming posterior wall of pelvis

auricular surface

lateral part that articulates with the os coxa through the sacroiliac joint of pelvis

sacral foramina

anterior openings in the sacrum

coccyx

4 fused vertebrae forming the triangular "tailbone"

sternum

anterior midline anchor for the ribs; composed of three bones

manubrium

superior portion of the sternum that articulates with the clavicle at its clavicular notch

jugular notch

important anatomical landmark located in the superior portion of the manubrium

body

middle portion of the sternum that articulates with T2-T7 rib cartilage

xiphoid process

small inferior portion of the sternum

costal cartilage

connective tissue that connects the ribs to the sternum

ribs

12 pairs, attached to T1 - T12 thoracic vertebrae

true rib

attached posteriorly to T1 - T7 and attached directly anteriorly to the sternum via costal cartilage

False rib

attached posteriorly to vertebrae T8 - T12; they are not directly attached to the sternum

floating rib

false ribs attached posteriorly to vertebrae T11-T12 but not attached to the sternum

temporomandibular joint

Superior nuchal line