1. Osseous Tissue (Histology)

2. Review: Bone is a type of connective tissue 2 Parts: 1. Cells (living)
2. Matrix (nonliving substance released by cells)
A. Fiber
B. Ground Substance

3. 1. Cells 2. Matrix Osteocytes— mature bone cells
Osteoblasts— bone-forming cells (germ cells or “bud” cells)
Osteoclasts —bone-destroying cells (“breakers”)
A. primarily collagen fibers
flexibility
tensile strength (the strength to endure stretching forces)
B. calcium salts (hardness)
contain calcium and phosphorus
great compressional strength (the strength to endure squeezing forces)
2. Matrix

4. Classification of Bone by Tissue Type
Two basic types of Tissue
1. Compact bone
Homogeneous
Looks “smooth”
2. Spongy bone
Small needle-like pieces of bone
Many open spaces
(like sponge)
Keep bones light
Figure 5.2b

5. Microscopic Anatomy of Bone
Figure 5.3a

6. Microscopic Anatomy of Bone
Osteon (Haversian system)
A unit of bone containing central canal and matrix rings
Central (Haversian) canal
Opening in the center of an osteon
Carries blood vessels and nerves
Perforating (Volkman’s) canal
Canal perpendicular to the central canal

7. Microscopic Anatomy of Bone
Lacunae
Cavities containing bone cells (osteocytes)
Arranged in concentric rings
Lamellae
Rings around the central canal
Sites of lacunae

8. Microscopic Anatomy of Bone
Canaliculi
Tiny canals
Radiate from the central canal to lacunae
Form a transport system connecting all bone cells to a nutrient supply

9. Microscopic Anatomy of Bone
Figure 5.3b–c