1. The Skeletal System

2. Functions of Bones Support of the body Protection of soft organs
Movement due to attached skeletal muscles
Storage of minerals and fats
Blood cell formation

3. The Skeletal System Parts of the skeletal system
Bones (skeleton)
Joints
Cartilages
Ligaments
Divided into two divisions
Axial skeleton
Appendicular skeleton

4. Bones of the Human Body The adult skeleton has 206 bones
Two basic types of bone tissue
Compact bone
Spongy bone
Figure 5.2b

5. Classifications of Bones
Page 144
Figure 5.1

6. Classification of Bones
Long bones
Typically longer than wide
Have a shaft with heads at both ends
Contain mostly compact bone
Examples: Femur, humerus

7. Long Bone Anatomy Diaphysis Epiphysis Shaft
Composed mostly of compact bone
Epiphysis
Ends of the bone
Composed mostly of spongy bone
Page 145
Figure 5.2a

8. Long Bone Anatomy Periosteum Outside covering of the diaphysis
Fibrous connective tissue membrane
Endosteum
Lines the inner marrow cavity
Red marrow
Yellow marrow
Figure 5.2c

9. Classification of Bones
Short bones
Generally cube-shaped
Contain mostly spongy bone
Examples: Carpals, tarsals

10. Classification of Bones
Flat bones
Thin and flattened
Usually curved
Thin layers of compact bone around a layer of spongy bone
Examples: Skull, ribs, sternum

11. Classification of Bones
Irregular bones
Irregular shape
Do not fit into other bone classification categories
Example: Vertebrae and hip

12. Skeletal Divisions Axial Skeleton Appendicular Skeleton
Bones of the skull and cranium
Bones of the Vertebral Column
Bones of the ribs and sturnum
Appendicular Skeleton
Bones of the appendages and pectoral and pelvic girdles

13. The Axial Skeleton Forms the longitudinal part of the body
Skull: 8 cranial bones, 14 facial
Vertebral column
Thorax

14. The Cranium Frontal Bone
Forms the forehead and superior surface of each eye socket (orbital)
Frontal sinuses are air filled pockets that produce mucus that cleans and moistens the nasal cavities

15. The Cranium Parietal Bones
Posterior to the frontal bones, located on each side
Forms the roof and superior walls of the cranium

16. The Cranium Occipital Bone
Posterior and inferior portions of the cranium
Surrounds the foramen magnum (opening that connects the cranial cavity
with the spinal cavity)

17. The Cranium Temporal Bones
Lie below the parietal bones and contribute to the sides and base of the cranium

18. The Cranium Sphenoid Bone Forms part of the floor of the cranium
Unites the cranial and facial bones
“Bat” shaped
Contains sphenoidal sinuses

19. The Cranium Ethmoid Bone Consists of two “honeycombed” masses of bone
Forms part of the cranial floor
Two projections
Superior conchae
Middle conchae

20. The Skull Zygomatic Bones Found on both sides of the face
Bone curves laterally to form the cheek bone
Forms lateral walls of the orbits
Figure 6-14

21. The Skull Mandible Bone of the lower jaw
Articulates with the temporal bone at the mandibular fossa
Mobile

22. The Skull Maxillary Bone
Articulates will all bones of the face, except the mandible
Forms:
The floor and medial portions of the rims of the orbits
The walls of the nasal cavity
The anterior roof of the mouth
Figure 6-14

23. The Skull Nasal Articulate with the frontal bone and maxillary bone
Form a bridge midway between the orbits
Figure 6-14

24. The Skull Lacrimal Bones
Located within the orbits, on the medial surfaces
Articulate with the frontal, ethmoid, and maxillary bones
Provide a passageway for the lacrimal (tear) ducts
Figure 6-14

25. The Skull Palatine Bone Paired bones of the bony (hard) palate
Roof of the mouth
Contribute to the floor of the nasal cavity
Figure 6-14

26. The Skull Foramen Magnum
Connects the cranial cavity with the spinal cavity
The spinal cord passes through this opening and connects to the inferior portion of the brain
Figure 6-14

27. Review…
Figure 5.7

28. Review…
Figure 5.11

29. Review…
Figure 5.9