1. Bones and Skeletal Tissues

2. Location of Bones and Cartilages
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Location of Bones and Cartilages

3. Types of Skeletal Cartilages
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Types of Skeletal Cartilages
Three types
1. Hyaline cartilage
Provides support, flexibility, and resilience
Collagen fibers only; most abundant type
Articular skeleton, costal (ribs), respiratory, nasal cartilage
2. Elastic cartilage
Similar to hyaline cartilage, but contains elastic fibers
External ear and epiglottis
3. Fibrocartilage
Thick collagen fibers—has great tensile strength
Menisci of knee; vertebral discs

4. © 2013 Pearson Education, Inc.
Important Point!
cartilage is not "turned into" bone, it is replaced by bone in a complicated process
**hyaline cartilage forms the model for the bones in a developing embryo.
Growth and reshaping occurs in two ways: interstitial growth and appositional growth.

5. Growth of Cartilage Appositional growth: Interstitial growth
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Growth of Cartilage
Appositional growth:
takes place "at the edge" of the cartilage mass
Interstitial growth
takes “in the middle" of the mass of cartilage.
Calcification of cartilage- Depositing calcium
Occurs during normal bone growth
Youth and old age
Hardens, but cacified cartilage is not bone!

7. Review Questions: pg 196 M.C 3, 4, 10, Short Answer: 15, 18,
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Review Questions: pg 196
M.C 3, 4, 10, Short Answer: 15, 18,

8. Classification of Bones
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206 named bones in Adult skeleton
Divided into two groups: See fig. 7.1
Axial skeleton and Appendicular skeleton

9. Classification of Bones by Shape
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Classification of Bones by Shape
Long bones
Longer than they are wide
Limb, wrist, ankle bones
Short bones
Cube-shaped bones (in wrist and ankle)
Sesamoid bones (within tendons, e.g., Patella)
Vary in size and number in different individuals
Flat bones
Thin, flat, slightly curved
Sternum, scapulae, ribs, most skull bones
Irregular bones
Complicated shapes
Vertebrae, coxal bones

10. Figure 6.2 Classification of bones on the basis of shape.
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Flat bone (sternum)
Long bone
(humerus)
Irregular bone (vertebra),
right lateral view
Short bone (talus)

11. Functions of Bones 1. Support: Standing upright, sitting
2. Protection: soft organs
3. Movement: muscles attached
4. Storage: fat, calcium, phosphorus
5. Blood Cell Formation: hematopoiesis
6. Hormone production
Osteocalcin
Regulates bone formation

12. Bones Are organs Three levels of structure
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Bones
Are organs
Contain different types of tissues
Bone (osseous) tissue, nervous tissue, cartilage, fibrous connective tissue, muscle and epithelial cells in its blood vessels
Three levels of structure
Gross anatomy
Microscopic
Chemical

13. Gross Anatomy: Bone Texture
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Gross Anatomy: Bone Texture
Compact and Spongy bone
Compact
Dense outer layer; smooth and solid
Spongy: also called trabecular
Less dense- open spaces

14. Structure of Short, Irregular, and Flat Bones
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Structure of Short, Irregular, and Flat Bones
Thin plates of spongy bone covered by compact bone
Plates sandwiched between connective tissue membranes
Periosteum (outer layer) and endosteum (inner layer)
No shaft or epiphyses
Bone marrow throughout spongy bone; no marrow cavity

15. Long Bones Epiphyses Bone ends
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Long Bones
Epiphyses
Bone ends
External compact bone; internal spongy bone
Articular cartilage covers articular surfaces
Between is epiphyseal line
Remnant of childhood bone growth at
epiphyseal plate Diaphysis
Tubular shaft forms long axis
Compact bone surrounding medullary cavity

16. © 2013 Pearson Education, Inc.
Bone Membranes:
Endosteum
Periosteum

17. © 2013 Pearson Education, Inc.
Review Questions:
# 5, 21, 22

18. Hematopoietic Tissue in Bones
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Hematopoietic Tissue in Bones
Red marrow
Found within trabecular cavities of spongy bone and in flat bones (e.g., sternum)
In medullary cavities and spongy bone of newborns
Adult long bones have little red marrow
Heads of femur and humerus only
Yellow marrow can convert to red, if necessary

19. Table 6.1 Bone Markings (1 of 2)
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20. Table 6.1 Bone Markings (2 of 2)
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21. © 2013 Pearson Education, Inc.
Cells of Bone Tissue

23. Anatomy of Compact Bone
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Osteon or Haversian system
Structural unit of compact bone
Hollow tubes of bone matrix called lamellae
Collagen fibers in adjacent rings run in different directions
Withstands stress – resist twisting

24. Figure 6.7 Microscopic anatomy of compact bone.
Spongy bone
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Central
(Haversian) canal
Perforating
(Volkmann’s) canal
Endosteum lining bony canals
and covering trabeculae
Osteon
(Haversian system)
Circumferential
lamellae
Perforating (Sharpey’s) fibers
Lamellae
Periosteal blood vessel
Periosteum
Nerve
Vein
Lamellae
Artery
Central
canal
Canaliculi
Osteocyte
in a lacuna
Lacunae
Interstitial
lamella
Lacuna
(with osteocyte)

25. Chemical Composition of Bone: Inorganic Components
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Chemical Composition of Bone: Inorganic Components
Hydroxyapatites (mineral salts)
65% of bone by mass
Mainly of tiny calcium phosphate crystals in and around collagen fibers
Responsible for hardness and resistance to compression

26. Bone Fun Facts Half as strong as steel in resisting compression
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Bone Fun Facts
Half as strong as steel in resisting compression
As strong as steel in resisting tension
Last long after death because of mineral composition
Reveal information about ancient people
Can display growth arrest lines
Horizontal lines on bones
Proof of illness - when bones stop growing so nutrients can help fight disease