1. Skeletal System: General Osteology
Comparative Anatomy
Dr. Tony Serino
Biology Department
Misericordia Univ.

2. Skeletal System
Composed of mineralized CT and their supporting structures including: bone, cartilage, ligaments, tendons, and bursae
Functions: support, protection, homeostasis (specifically Ca++ regulation) and hempoiesis

3. General Osteology Composition
Cells –originate from mesechyme (undifferentiated mesodermal cells)
Extracellular Matrix
Ground substances: water, salts, cementing substances, glycoproteins
Fibers: collagen and elastin

4. Cartilage Avascular CT Appositional and interstitial growth possible
Perichondrium
Chondroblast
Lacuna
Chondrocyte
Matrix

5. Hyaline Cartilage

6. Elastic Cartilage

7. Fibrocartilage

8. Cartilage in Adult

9. Bone Heavily mineralized CT Highly vascular
Principle storage area of Calcium
Provides strength and structural support to body

10. Long Bone Anatomy

11. Flat Bone Anatomy
Trabeculae

12. Bone Histology

13. Haversian System Lamellae

14. Ossification Development of bony tissues
First bone to form is woven (premature) bone
This is eventually replace by mature bone (compact or spongy bone)
Two methods for creating bones:
Intramembraneous (bone replaces mesoderm membrane)
Endochondral (bone replaces an intervening cartilage model)

15. Intramembranous Ossification (Membrane bone formation)

16. Endochondral Ossification (Replacement Bone formation)

17. Epiphyseal (Growth) Plate
Reserve Cartilage (distal perichondrium)
Proliferating Cartilage (Growth zone)
Hypertrophic zone (Transforming zone)
Calcified matrix (Osteogenic zone)

19. Fracture Healing

20. Other Skeletal Tissue
Dentin –formed from odontoblasts; lay down dentin layer and retreat leaving small canaliculi (dentinal tubules); fond only in vertebrate teeth, and ganoid and placoid scales
Acellular bone (aspidin) –found in modern fish scales and cementum of teeth; from osteoblasts that create matrix and retreat without canaliculi
Enamel –secreted by ameloblasts; derived from ectoderm; secretes enameloid on dentin layer by enamel organ which dies when scale or tooth erupts through epidermis

21. Divisions of Skeletal System
Axial Skeleton
Fig. 7.1

22. Appendicular Skeleton
Fig. 7.21

23. Types of Bones

24. Sesamoid Bones

25. Wormian (Sutural) Bones
(Wormian Bone)

26. Articulations Functional Classifications Structural Classification
Synarthrotic (immovable)
Amphiarthrotic (slightly movable)
Diarthrotic (movable)
Structural Classification
Fibrous –held by fibrous tissue
Cartilaginous –held by cartilage
Synovial –synovial cavity within joint

27. Suture (synarthrotic, fibrous joint)
Found in bones of skull

28. Gomphosis (synarthrotic, fibrous)
Ligament cemented to tooth surface

29. Syndesmoses (amphiarthrotic, fibrous)

30. Synchondroses (Synarthrotic, cartilaginous)
Epiphyseal Plate

31. Synchondroses (synarthrotic, cartilaginous)

32. Symphyses (amphiarthrotic, cartilaginous)
Includes pubic symphysis

33. Synovial = diarthrotic joints
The synovial membrane filters the blood to create synovial fluid
This fluid lubricates and nourishes the joint
Some joints may have an additional wedge of cartilage within the joint (menisci)
Fig. 8.3

34. Knee (Anterior view)

35. Rotator Cuff of Shoulder

36. Bursae