Osseous Tissue (Histology)
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
1. Cells
•
•
•
Osteocytes— mature bone cells
Osteoblasts— bone-forming cells (germ cells or “bud” cells)
Osteoclasts —bone-destroying cells (“breakers”)
2. Matrix
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)
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
Microscopic Anatomy of Bone
Figure 5.3a
http://www.youtube.com/watch?v=4qTiw8lyYbs&NR=1
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
– Carries blood vessels and nerves
Microscopic Anatomy of Bone
• Lacunae
– Cavities containing bone cells (osteocytes)
– Arranged in concentric rings
• Lamellae
– Rings around the central canal
– Sites of lacunae
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
Microscopic Anatomy of Bone
Figure 5.3b–c