The skeletal system chapter discusses the classification and structure of bones. The major bone classifications include long bones, short bones, flat bones, and irregular bones. A long bone has an epiphysis, diaphysis, and other parts. Compact and spongy bone have different microscopic structures. The skeletal system is divided into the axial skeleton and appendicular skeleton. The axial skeleton includes the vertebral column, ribs, and skull. The appendicular skeleton includes the upper and lower limbs attached to the pectoral and pelvic girdles.

1. Chapter 7 Skeletal System

2. Bone Classification Long Bones Short Bones Flat Bones Irregular Bones Sesamoid Bones

3. Parts of a Long Bone epiphysis distal proximal articular cartilage diaphysis periosteum compact bone spongy bone medullary cavity endosteum marrow red yellow

4. Compact and Spongy Bone

5. Microscopic Structure of Compact Bone osteocyte bone cell osteon central canal w/ blood vessels w/ nerves perforating canal w/ blood vessels w/ nerves

6. Skeletal Organization Axial Skeleton head neck trunk Appendicular Skeleton upper limbs lower limbs pectoral girdle pelvic girdle

7. The only ‘floating’ bone

8. Vertebral Column cervical vertebrae (7) thoracic vertebrae (12) lumbar vertebrae (5) sacrum (5 fused) coccyx (tailbone)

9. Cervical Vertebrae Atlas – 1 st ; supports head Axis – 2 nd ; dens pivots to turn head

10. Thoracic Vertebrae long spinous processes rib facets

11. Lumbar Vertebrae large bodies thick, short spinous processes

12. Sacrum five fused vertebrae posterior wall of pelvic cavity

13. Coccyx tailbone four fused vertebrae

14. Thoracic Cage Protects viscera Role in breathing Ribs True ribs (7) False ribs (5) floating (2) Costal cartilages Sternum Manubrium Body Xiphoid process Thoracic vertebrae

15. Facial Skeleton Frontal (1) Parietal (2) Temporal (2) Occipital (1) Maxillary (2) Mandible (1) Zygomatic (2) Lacrimal (2) Nasal (2) Sphenoid (1) Ethmoid (1)

16. Facial Skeleton Frontal (1) Parietal (2) Temporal (2) Occipital (1) Maxillary (2) Mandible (1) Zygomatic (2) Lacrimal (2) Nasal (2) Sphenoid (1) Ethmoid (1) Vomer (1)

17. Skull Sphenoid (1) Ethmoid (1)

18. Infantile Skull Fontanels – fibrous membranes; “soft spots”

19. Pectoral Girdle shoulder girdle clavicles scapulae supports upper limbs

20. Upper Limb Humerus Radius Ulna Olecranon process Ulnar nerve Carpals Metacarpals Phalanges

21. Wrist and Hand Carpals (16) trapezium trapezoid capitate scaphoid pisiform triquetrum hamate lunate Metacarpals (10) Phalanges (28) proximal phalanx middle phalanx distal phalanx

22. Pelvic Girdle Coxae (2) supports trunk of body protects viscera

23. Coxae hip bones acetabulum ilium ischium ischial tuberosity pubis

24. Male and Female Pelvis Female iliac bones more flared broader hips pubic arch angle greater sacral curvature shorter and flatter lighter bones

25. Lower Limb Femur Longest bone of body Patella Tibia Medial malleolus Fibula Bears no weight Lateral malleolus Tarsals Metatarsals Phalanges

26. Ankle and Foot Tarsals (14) calcaneus* talus* navicular cuboid lateral cuneiform intermediate cuneiform medial cuneiform Metatarsals (10) Phalanges (28) proximal middle distal

27. Ankle and Foot

28. Bone Development Intramembranous Ossification bones originate within sheetlike layers of connective tissues broad, flat bones  skull bones (except mandible) Endochondral Ossification bones begin as hyaline cartilage most bones of the skeleton

29. Endochondral Ossification

30. Homeostasis of Bone Tissue Bone Resorption – action of osteoclasts Bone Deposition – action of osteo b lasts; “bone b uilders”

31. Bone Function Support and Protection gives shape to head, etc. supports body’s weight protects lungs, etc. Body Movement interacts with muscles bones act as rigid bar of a lever Blood Cell Formation hematopoiesis red marrow Inorganic Salt Storage calcium phosphate magnesium sodium potassium