Axial Skeleton

The Axial Skeleton

7-1

The Complete Skeleton

•Axial skeleton

–Skull –Hyoid bone –Vertebral column –Thoracic (rib) cage

Fig. 7.1

•Appendicular skeleton –Limbs –Girdles

7-2

Superior View of Skull or Cranium • Functions

– Protects brain – Supports organs of special senses

• Superior view of skull – Parietal bones-top of skull – Frontal bone-forehead

Modified from Fig. 7.2

7-3

Posterior View of Skull • Hard palate-roof of mouth – Palatine – Maxilla

Occipital -back of head

Modified from Fig. 7.3 7-4

Lateral View of Skull • Temporal bone External auditory meatus-earhole • Zygomatic bonearch of cheek

• Mandible- Jawbone • Sphenoid bone- at temple Modified from Fig. 7.4

7-5

Frontal View of Skull • Zygomatic bones • Nasal bones-top of nose

• Inferior nasal concha-inside nose • Maxilla-moustache bone

Modified from Fig. 7.6 7-6

Bones and Openings of Right Orbit • Ethmoid bone • Lacrimal bone • Sphenoid bone

Modified from Fig. 7.8

7-7

Inferior View of Skull • Foramen magnum • Occipital condyles • Styloid processes

Modified from Fig. 7.12

7-8

Hyoid Bone and Auditory Ossicles • Hyoid bone – Unpaired – No direct bony attachment to skull – Attachment point for some tongue muscles – Attachment point for neck muscles that elevate larynx during speech and swallowing

• Auditory ossicles Fig. 7.14

– Malleus, incus and stapes 7-9

Vertebra • Parts – – – –

Body Vertebral foramen Vertebral arch Superior and inferior articular processes and facets – Transverse process – Articular facets for rib – Spinous process Modified from Fig. 7.19 7-10

Vertebral Column • Regions – – – – –

Cervical (7 vertebrae) Thoracic (12 vertebrae) Lumbar (5 vertebrae) Sacral bone (1) Coccygeal bone (1)

Fig. 7.15 7-11

Cervical Vertebrae • Atlas – First vertebra

• Axis – Second vertebra – Dens or odontoid process

Modified from Fig. 7.22

7-12

Thoracic and Lumbar Vertebrae

Modified from Fig. 7.23

Modified from Fig. 7.24 7-13

Sacrum and Coccyx

Modified from Fig. 7.25

7-14

Thoracic or Rib Cage and Sternum

Modified from Fig. 7.26

Parts •Thoracic vertebrae •Ribs (12 pair) •True or Vertebrosternal •False •floating •Sternum (manubrium, body, Xiphoid process •) 7-15