Axial Skeleton Know Sheet

Exercise 10 and 12 (fetal skull)

Skull (Cranium, Facial Bones, Mandible, Hyoid)

Sutures: Sagittal, Coronal, Lambdoidal, Squamous (Squamosal)

Wormian or Sutural Bones ("Inca Bone")

Fetal Skull: Significance of fontanels.

Some adult skull bones are "composites" -- what does this mean?

Cranium (interface with brain)

Frontal: supraorbital foramen or notch (varies), supraorbital margin, glabella, anterior cranial fossa. Frontal bone sometimes has a mid-sagittal suture (metopic suture).

Parietal (skull roof). Note the sutures it makes with other bones.

Sphenoid: greater and lesser wings, body, optic foramen, sella turcica (translation and significance), optic foramen (canal). The foramen rotundum and ovale are passageways for branches of the ___ cranial nerve (the trigeminal). Superior orbital fissure (nerves 3, 4, 5 and 6)

Temporal: zygomatic process, mandibular fossa, external auditory meatus, mastoid process, styloid process (may be broken off). Know left from right.

Occipital: Occipital condyles (what articulates with them?), external occipital protuberance, foramen magnum (significance), posterior cranial fossa. Compare with fetal skull.

Ethmoid: concha (turbinates), crista galli (translation?), cribriform plate, perpendicular plate

( nasal septum), olfactory foramina (significance -- what goes through them in life?)

Maxilla: alveoli/alveolar margin, palatine processes (part of hard palate), maxillary sinus, incisive fossa

Zygomatic: forms part of zygomatic arch

Nasal

Lacrimal: lacrimal sulcus or fossa (tear duct)

Palatine: horizontal plate. Forms rear of hard palate.

Vomer: "plow"; part of nasal septum

Inferior nasal conchae (turbinates)

Mandible: Coronoid process, condylar process, ramus, angle, mandibular symphysis, alveoli.

Teeth: (per side in adult) incisors (2) , canine (1), premolars (2) and molars (3).

Hyoid: Body with greater and lesser horns; What is the significance of hyoid bone?

Sinuses: maxillary, sphenoid, ethmoid, frontal. What is the function of the sinuses?

Vertebral Column

General structure: body (centrum); intervertebral discs; neural arch (lamina + pedicle); vertebral foramen; spinous process, transverse process; superior and inferior articular surfaces.

Cervical vertebrae (7)

Atlas vs Axis; transverse foramen; Odontoid process (dens) of axis.

Thoracic vertebrae (12)

Downward facing spinous processes, facets for rib tubercles. whole vs demi-facet.

(note: facet is preferred over fovea).

Lumbar vertebrae (5)

Heavy blunt spinous processes, no rib articulations.

Sacrum (5 fused vertebrae)

Ala, auricular surfaces, transverse lines, median sacral canal, medial sacral crest, foramina, apex and base.

Coccyx (3-5 fused vertebrae): Coccygeal cornua (horns) on first coccygeal vertebra.

Rib Cage

Sternum:

Manubrium, body and xiphoid process. Jugular notch, clavicular notch, sternal angle.

Ribs:

True (1-7) vs False (8-12) vs Floating (11 & 12). Head, neck, angle and shaft. tubercle and facets.

Head of rib articulates with body of vertebra, tubercle of rib articulates with transverse process of vertebra

Costal cartilages (made of __________ cartilage)