Axial Skeleton

Ch. 7

Skull

• 22 bones• Cranial (8)– Frontal, parietal (2), temporal (2), occipital,

sphenoid, ethmoid• Facial (14)– Nasal (2), maxillae (2), zygomatic (2), mandible,

lacrimal (2), palatine (2), inferior nasal conchae (2), vomer

Cranial Bones

Facial Bones

Fontanelles

• Dense connective tissue filled space between skull bones at birth

Sutures

• Immovable joint found between skull bones• Begin to ossify between age 20-30• Sutures– Coronal – between frontal bone and 2 parietal bones– Sagittal – between two parietal bones– Lambdoid – between parietal bones and occipital

bone– Squamous – between parietal bones and temporal

bones

Sutures

Vertebral Column

• 26 vertebrae• Numbered by region– C-1, T-5, L-3, etc.

• 5 regions– Cervical (neck) – 7– Thoracic (chest) – 12– Lumbar (lower back) – 5– Sacrum – 5 fused– Coccyx – 4 fused

Vertebral Column

• Spinal curvatures – one for each region

Vertebrae

• C-1 – atlas; C-2 – axis

Rib Cage

• 1-7 are true ribs – attached to sternum• 8-12 are false ribs – not attached to sternum• 11-12 are floating ribs – not attached to

anything• Intercostal space – space between ribs

Rib Cage and Sternum

• Clavicle• Xyphoid

process• Sternum