1. Chapter 6 Osseous Tissue & Bone Structure

2. 6-1: Skeletal System Functions
Skeletal system includes bones, cartilages, ligaments, connective tissues
Functions: support, store minerals, produce blood cells, protection, leverage

3. 6-2: Bone Classification
Bone Shapes
Sutural vs. irregular vs. short vs. flat vs. long vs. sesamoid bones
Bone Markings
External & internal features (Table 6-1)
Bone Structure
Diaphysis vs. epiphysis; compact bone vs. spongy bone

6. 6-3: Bone Composition Bone Matrix Bone Cells
Ca3(PO4)2 & collagen fibers
Bone Cells
Osteocytes arranged in layers (lamallae); canaliculi connect lamallae
Osteoblasts vs. osteoclasts
Osteogenesis vs. osteolysis

7. 6-4: Compact & Spongy Bone
Compact Bone
Osteocytes arrange in layers around a central canal to form an osteon
Spongy Bone
Matrix forms a mesh of fibers
Location of red & yellow bone marrow
Periosteum vs. Endosteum

10. 6-5: Bone Formation Endochondral Ossification
Bones begin as hyaline cartilage; are replaced by bone
Examine steps in Figure 6-10
Primary vs. secondary ossification centers
Epiphyseal cartilages (growth plates)

11. Intramembranous Ossification
Mesenchymal cells form flat bones
Examine steps in Figure 6-12
Spongy bone becomes more compact

12. 6-6: Bone Growth & Development
Osteoblasts & osteoclasts continually remove & replace osteons
Rate of formation & destruction is usually equal

13. 6-7: Exercise & Hormones Effects of Exercise on Bone
Stresses to bone promote osteoblast activity
Hormonal & Nutritional Effects
Normal bone growth depends on calcium, vitamins (esp. C), growth hormone, estrogens & androgens

14. 6-8: Calcium & Bone Physiol.
Calcium is needed for neuron & muscle cell activity
Hormones & Calcium Balance
Parathyroid hormone (PTH) stimulates osteoclasts; increases blood calcium
Calcitonin inhibits osteoclasts; decreases blood calcium

15. 6-9: Fractures Bone blood clot forms after break
External callus forms over internal callus
Osteoblasts replace calluses; osteoblasts & osteoclasts continue to remodel bone

16. 6-10: Osteopenia
Osteopenia—inadequate ossification (loss of bone mass)
Osteoporosis—loss of bone mass compromises normal function