1. Chapter 5 The Skeletal System

2. The Skeletal System Parts of the skeletal system  Bones (skeleton)  Joints  Cartilages  Ligaments Divided into 2 divisions  Axial skeleton  Appendicular skeleton

3. Functions of Bones  Support body  Protect soft organs  Movement due to attached skeletal muscles  Storage of minerals and fats  Blood cell formation

4. Bones of the Human Body The skeleton has 206 bones Two types of bone tissue  Compact bone - Homogeneous  Spongy bone - Small needle-like pieces of bone - Many open spaces

5. Classification of Bones on the Basis of Shape 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 - Ex: Femur, - humerus

7. Classification of Bones Short bones  Generally cube-shape  mostly spongy bone - Ex: Carpals, tarsals

8. Classification of Bones Flat bones  Thin and flattened  Usually curved  Thin layers of compact bone around a layer of spongy bone -Ex: Skull, ribs, sternum

9. Classification of Bones Irregular bones  Irregular shape  Don’t fit into other classification categories -Ex: Vertebrae and hip

10. Axial Skeleton - Axial Skeleton - longitudinal part of the body Three parts  Skull  Vertebral column  Bony thorax

11. The Skull  Two sets of bones - Cranium - Facial bones  Bones are joined by sutures  Only the mandible is attached by a freely movable joint

12. Bones of the Skull

13. Human Skull, Superior View

14. Human Skull, Inferior View

15. Paranasal Sinuses  Hollow parts of bones surrounding nasal cavity  Functions: -Lighten the skull -Resonate and amplify voice

16. The Hyoid Bone  Only bone that doesn’t articulate with another bone  Moveable base for tongue

17. The Bony Thorax  Forms cage to protect major organs  3 parts - Sternum - Ribs - Thoracic vertebrae

18. The Vertebral Column  separated by intervertebral discs  normal curvature  named based on location

19. Structure of a Typical Vertebrae

20. Characteristics of Cervical Vertebrae

21. Characteristics of Thoracic & Lumbar Vertebrae

22. Plate Test – know these structures! Atlas (C1) lamina Axis (spinous process – C2) Body of cervical vertebra Body of lumbar vertebra Body of sternum Body of thoracic vertebra Cervical vertebra Chondral end Coccyx Coronal suture (Frontal) Costal cartilage Demifacet Ethmoid bone Facet (articulating process) False rib Floating rib Foramen magnum Head (facets for vertebra) Intervertebral disc (annulus fibrosous)

23. Lacrimal Lamina Lamina (lumbar vert) Ligament in vertebra Lumbar Vertebra (Spinous process) Mandible Mastoid process (temporal bone) Maxilla Nasal bones Nerve in vertebra Occipital bone Occipital condyle Palatine Parietal bone Pedicle Sacrum Sagittal suture Spinous process Styloid process (temporal bone) Thoracic vertebra Transverse process True Rib Vertebral foramen Vomer Xiphoid process (sternum) Zygomatic bone