3. Skeleton Divided into sections Axial Appendicular Made of 206 bones

4. Provides a framework that supports and protects organs in the dorsal and ventral body cavities Joints are rigid and have limited movement but are very strong Made of 80 bones

5. Skull and Associated Bones Occipital bone (1) Parietal Bones (2) Frontal Bone Temporal Bone (2) Sphenoid Bone Ethmoid bone

8. Skull and Associated Bones Protect and guards entrance to the digestive and respiratory tract Cranial bones- enclose the cranial cavity, a fluid filled chamber that cushions and supports the brain Inner surface has blood vessels, nerves, and membranes that stabilize the brain Outer surface provides area for attachment of muscle that move eyes, jaws, and head

9. Sutures of the skull Connections between the skull bones are immovable joints called sutures (connection of mandible is an exception)

10. Skull Sutures Lamboidal suture- arches across the posterior surface of the skull. Separates the occipital bone from the parietal bones. Coronal Suture- arches across the top of the skull. Separates the frontal bone from the parietal bones.

11. Sutures cont. Sagittal Suture- goes between the lamboidal and coronal sutures splitting the 2 parietal bones Squamous Sutures (2) - one on each side of the head between the parietal and temporal bones

13. Facial Bones (14) Maxillary bones Palatine bones Nasal bones Vomer (1) Inferior nasal conchae Zygomatic bones Lacrimal bones Mandible (1)

15. Infant Skull Bone growth is attempting to keep up with brain development, so at birth bones haven’t fused together yet At approx. age 5 brain stops growing so does the skull, and the cranial sutures develop

16. Fontanels Fontanel- large fibrous areas between skull bones Anterior, Occipital, Sphenoidal, and Mastoid Fontanels Occipital, sphenoidal, and mastoid fontanels disappear 1-2 months after birth, and the anterior fontanel persists until age 2