This chapter should help the student to:

• Describe bone as a connective tissue in terms of its cells, fibers, and ground substance.
  
• Compare bone cell types in terms of their origin, structure, and primary functions.
  
• Relate the physical properties of bone tissue to specific tissue components.
  
• List the bone tissue types and name the sites where each may be found.
  
• Compare the two processes of bone histogenesis in terms of embryonic tissue of origin, intermediate steps, structure of the mature tissue, and location in the body.
  
• Compare the steps of bone histogenesis with those of fracture repair.
  
• Know the alterations in tissue structure that occur during bone growth and remodeling.
  
• Explain the effects of nutrients and hormones on bone tissue structure and function.
  
• Identify bone types, cell types, and named structures in micrographs of bone tissue.
  
• List the types of joints and compare them in terms of their structure, mobility, and location.

1. List the functions of bone (I.B).

2. Describe two methods of preparing bone for microscopy that are necessitated by its hardness (III.A). Which method resembles a step in bone resorption (III.A.1.d. and D.1.a)?

3. List the functions of osteoblasts and the organelle(s) associated with each function (III.A.1.b).

4. Describe osteoblast cytoplasmic staining and name the cell components stained (III.A.1.b).

5. Describe the relationships among osteoprogenitor cells, osteoblasts, and osteocytes (III.A.1.a–c).

6. Compare osteocytes (III.A.1.c) with osteoblasts (III.A.1.b) in terms of their shape, filopodia, amount of RER, location, and rate of matrix synthesis.

7. How can osteocytes located far from capillaries survive when nutrients, oxygen, and wastes cannot diffuse through calcified bone matrix (III.A.1.c)?

8. Describe osteoclasts (III.A.1.d) in terms of:

1. 
   

   Size

   
   
2. 
   

   Number of nuclei

   
   
3. 
   

   Precursor cells

   
   
4. 
   

   Staining properties

   
   
5. 
   

   Organelles present

   
   
6. 
   

   Major function

   
   
7. 
   

   Substances secreted

   
   
8. 
   

   Location and function of ruffled border

   
   
9. 
   

   Reaction to parathyroid hormone

   
   
10. 
    

    Reaction to calcitonin

9. List the inorganic components of bone matrix. Which two are most abundant (III.A.2.b)?

10. Describe the composition of the organic matter (osteoid) of bone matrix (III.A.2.a.[1] and [2]).

11. Compare endosteum and periosteum in terms of location, thickness, number of layers, and cell types present (II.B).

12. Compare compact and spongy bone in terms of the presence of cavities and trabeculae, histologic structure under high-power magnification, and location (III.B.1 and 2).

13. Compare primary and secondary bone (III.C.1 and 2) in terms of:

1. 
   

   Relative permanence

   
   
2. 
   

   Type prevalent in adults

   
   
3. 
   

   Orientation of collagen fibers

   
   
4. 
   

   Cellularity (cell-to-matrix ratio)

   
   
5. 
   

   Presence of lamellae

   
   
6. 
   

   Relative mineral content

14. Sketch an osteon (haversian system) in cross-section (III.C.2.b; Fig. 8–1) and label the following:

1. 
   

   Haversian canal

   
   
2. 
   

   Endosteum

   
   
3. 
   

   Blood vessel

   
   
4. 
   

   Nerve

   
   
5. 
   

   Lymphatic vessel

   
   
6. 
   

   Lamellae

   
   
7. 
   

   Lacunae

   
   
8. 
   

   Osteocytes

   
   
9. 
   

   Filopodia

   
   
10. 
    

    Canaliculi

15. Compare haversian and Volkmann’s canals in terms of contents, orientation, and encirclement by bony lamellae (III.C.2.b).

16. Beginning with mesenchyme, list the steps in intramembranous bone formation (III.C.1.a).

17. Beginning with mesenchyme, list the steps in endochondral bone formation (III.C.1.b).

18. Compare your answers to questions 16 and 17. At what point do the two processes diverge? At what point do they reconverge? What is the major difference between the two types?

19. Beginning with the zone of resting cartilage and ending with the zone of ossification, name in order the zones of endochondral bone formation seen in longitudinal section of an epiphyseal plate (III.C.1.b.[1].[c]–[f]).

20. Compare the locations and staining properties of calcified cartilage matrix and bone matrix (III.C.1.c).

21. How do long bones grow in length and width (III.C.3)?

22. Describe the steps in long bone fracture repair (III.C.4). Compare this with your answer to question 17.

23. Using what you have learned about the mechanisms of bone growth and remodeling, describe the cellular events that must occur in the bony alveolus (socket) of a tooth to allow a permanent reorientation of that tooth through the application of braces (III.C.1.a and 2.a).

24. Describe the effects of the following on bone tissue:

1. 
   

   Increased circulating parathyroid hormone (III.D.1.a)

   
   
2. 
   

   Increased circulating calcitonin (III.D.1.b and 3.b)

   
   
3. 
   

   High and low levels of calcium in the blood (III.D.1.a&b)

   
   
4. 
   

   Dietary deficiency of protein and vitamin C (III.D.3.a and f)

   
   
5. 
   

   Vitamin D deficiency (III.D.3.c)

   
   
6. 
   

   Vitamin A deficiency and excess (III.D.3.d&e)

   
   
7. 
   

   Insufficient and excess growth hormone in children and adults (III.D.4.b)

25. Compare osteomalacia (III.D.3.b) and osteoporosis (III.D.2) in terms of etiology and effect on the mineral-to-matrix ratio in bone.

26. Compare synarthroses and diarthroses in terms of the movement they permit (IV.A and B).

27. Compare synostoses, synchondroses, and syndesmoses in terms of the tissue between the bones. Give examples of body sites where each occurs (IV.A).

28. Draw a schematic diagram of a diarthrosis (Fig. 8–2) and label the following: