1. Ch. 6 Bone Tissue & The Skeletal System

2. Appendicular Skeleton
Introduction
206 bones
Parts: bones, cartilage, joints
Divisions
Axial Skeleton
Appendicular Skeleton
Figure 6.1

3. 6.1 The Functions of The Skeletal System
Objectives
List and describe the functions of the Skeletal System 1. 2. 3. 4.
5. Minerals

4. 6. 2 Bone Classification by Shape. See Table on p
6.2 Bone Classification by Shape * See Table on p. 217 for general functions of each
(e) Sesamoid bone
Figure 5.1

5. 6.3 Bone Structure A. Arrangement of Bone Tissue B. Gross Anatomy–
1. Compact Bone
2. Spongy Bone- Diploë
B. Gross Anatomy–
1. Long Bone

6. a) Epiphysis = Type bone” Epiphysial plate Epiphyseal line
1. Long Bone …
a) Epiphysis =
Type bone”
Epiphysial plate
Epiphyseal line
b) Diaphysis =
Type bone:
Medullary cavity:
Child:
Adult

7. Structure of a Long Bone … c) Periosteum =
Composition: Overall Function:
Nutrient foramen
d) Endosteum =
e) Articular Cartilage

8. 2. Flat Bones 3. Bone Markings * see Table p. 212 Articulations
6.3 Bone Structure …
2. Flat Bones
Spongy bone: Location
Compact bone: Location
3. Bone Markings
* see Table p. 212
Articulations
Projections
Holes
Figure 5.2b

9. Gross Anatomy … 3. Bone Markings …
Table 6.1

10. Bone Structure … C. Bone Cells and Tissue– Microscopic Anatomy
Composition of Bone:
1. Cells of Bone Tissue
Osteogennic cells =
Turn into:
Osteoblasts – make:

11. Bone Structure … C. Bone Cells and Tissue– Microscopic Anatomy …
Osteocytes
Location:
Function:
Communicate:
Can sense stress in bone, then:
Osteoclasts (derived from WBCs)

12. C. Bone Cells and Tissue …
2. Bone Tissue
a) Compact Bone
Function
Osteons = Haversian System
Central Canal
Perforating Canals
Lacuna
Canaliculi
Osteon

13. a) Compact Bone … Osteons …
Lamella
In Osteon
Interstitial lamellae:
Circumferential lamellae:
Osteon
Figure 6.6a

14. C. Bone Cells and Tissue … 2. Bone Tissue …
Spongy Bone
Trabeculae
Function

15. 6.4 Bone Formation and Development
A. Introduction
1. Embryo: Skeleton is
Ossification:
Two Methods (Pathways
Intramembraneous–
Endochondral–
2. Baby Childhood  Early Adulthood
Postnatal Bone Growth
Remodeling
3. Adulthood  Old Age

16. 6.4 … B. Intramembranous Ossification Types of Bones:
1. Ossification Center appears
Mesenchyme cells:
They differentiate into:
Osteoblasts forms an Ossification Center
Figure 6.7.1

17. Intramembranous Ossification …
2. Osteoid is secreted
Osteoblasts secrete osteoid
Minerals
Osteoblasts
Osteogennic  Osteoblasts
Figure 6.7.2

18. Intramembranous Ossification …
3. Early Bone and Periosteum Forms
Osteoid around blood vessels:
Osteoblasts:
Figure 6.7.3

19. Intramembranous Ossification …
4. Mature Bone Formed
Osteoblasts:
Certain blood vessels:
At Birth:
Function:
Last Bones to Ossify:
Figure 6.7.4

20. Figure 6.8 Endochondral ossification in a long bone.
Slide 7
Week 9
Month 3
Birth
Childhood to
adolescence
Articular
cartilage
Secondary
ossification
center
Epiphyseal
plate
cartilage
Hyaline
cartilage
Spongy
bone
formation
Medullary
cavity
Primary
ossification
center 3
Figure 6.8 Endochondral ossification in a long bone.
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21. 6.4 Bone Formation and Development …
C. Endochondral Ossification
Bones:
Overall:
Cartilage:
1. Mesenchymal Cells Differentiate into Chondrocytes
Chondrocytes form:
2. Perichondrium forms
3. Primary Ossification Center forms
(fetus month 3)
Cartilage Matrix:
Chondrocytes:
Blood Vessels:

22. Mesenchymal cells of Periosteum: Bone Collar– Osteoblasts:
C. Endochondral Ossification …
Primary Ossification Center forms …
3. Primary Ossification Center forms …
Mesenchymal cells of Periosteum:
Bone Collar– Osteoblasts:
Primary Ossification Center: (fetus month 2-3)
4. Cartilage Model continues to grow at epiphyses
Cavities form: in middle of diaphysis

23. 5. Spongy Bone Forms Periosteal Bud: Early Spongy Bone: Month 3 Spongy
Slide 4
Month 3
5. Spongy Bone Forms
Periosteal Bud:
Early Spongy Bone:
Spongy
bone
formation
Blood
vessel of
periosteal
bud

24. Figure 6.8 Endochondral ossification in a long bone.
Slide 5
Birth
Epiphyseal
blood vessel
Secondary
ossification
center
6. Secondary Ossification Centers Form (after Birth)
Medullary Cavity:
Hyaline model grows:
Ossification:
Medullary
cavity
Figure 6.8 Endochondral ossification in a long bone.
© 2013 Pearson Education, Inc.

25. Figure 6.8 Endochondral ossification in a long bone.
Childhood to
Adolescence
Slide 6
Articular
cartilage
7. Ossification Ends
Epiphyseal Plate
Skeleton:
Cartilage in 2 places
Long Bone: (SEE “D” NEXT)
Epiphyseal Line
Growth:
Spongy
bone
Epiphyseal
plate
cartilage
Figure 6.8 Endochondral ossification in a long bone.
© 2013 Pearson Education, Inc.

26. Plate  Epiphyseal line
Bone
Plate  Epiphyseal line

27. 5 Functional Zones in Long Bone Growth
D. How Bones Grow In Length
Occurs at
Ossification:
4 Zones:
(5 zones if include Reserve)
Growth ends:
5 Functional Zones in Long Bone Growth

28. 5 Functional Zones in Long Bone Growth
Reserve (Resting zone) =
Proliferation-Growth zone – cartilage cells:
(produce cells on either side)
Maturation and Hypertrophic zone:
Calcified Matrix (Calcification zone) - the matrix becomes:
Zone of Ossification (Osteogenic zone):
(later eroded by osteoclasts to form medullary cavity)

29. Modeling: occurs during a bone’s growth
6.4 … E. Growth in Width
Modeling: occurs during a bone’s growth
1. Appositional Growth--in diameter:
2. Osteoclasts of Endosteum
3. Proportions:
WIDTH GROWTH
Shape before Appositional Growth 3. 1. 2.

30. Figure 6.11 Long bone growth and remodeling during youth.
Bone growth--width
Bone remodeling
Bone growth--Length
Articular cartilage
Cartilage
grows here.
Bone
replaces cartilage
here.
Epiphyseal plate
2. Bone that was
here has been
resorbed.
Cartilage
grows here.
1. Appositional
growth adds
bone here.
Bone replaces
cartilage here.
3. Bone that was
here has been
resorbed.
© 2013 Pearson Education, Inc.

31. - 5-10% annually in an adult Function: 1) 2) - Importance of Calcium
6.4 … E. Bone Remodeling When: primarily during Bone Growth - Also during adult life
- 5-10% annually in an adult
Function: 1) 2)
- Importance of Calcium
Nerve
Muscle
Blood Clotting
Cell division

32. END Continue to PPT #2

33. Review Question
3. Impact resistance is provided by _________ bone while the mass of a bone is lightened by ____________ bone without jeopardizing strength. Bone, in general, helps to store ___________and fat.
Compact …. Spongy …... Minerals

34. Review Question
4. Bones are covered with a layer of dens connective tissue known as the _____________ and is 65% ______________________. Bone cells include stem cells known as ______________, bone makers called ____________, and bone breakers called ____________.
periosteum
hydroxyapatites
osteogenic cells
osteoblasts
osteoclasts

35. Participating…
5. Blood vessels deliver nutrients to bone through long ___________ canals running through the middle of each osteon and sideways _____________ canals. Bone cells trapped inside lacunae receive nourishment via ______________ that radiate from the central canal and __________ fibers provide resistance to stress due to their arrangement within _____________
central
perforating
canaliculi
collagen
lamellae

36. Review Questions
6. Intermembranous ossification forms the clavicles and most _______ bones of the skull. Endochondral ossification occurs when hyaline ___________ is replaced by bone. __________ ossification centers typically become ___________ cavities in long bones, but secondary ossification centers remain what type of bone?
flat
cartilage
Primary
medullary
spongy
Hyaline
cartilage
Epiphyseal
blood vessel
plate
Medullary
cavity
Articular
Bone collar 1 2 3 4 5

37. Cartilage Perichondrium: Tissue Functions resists outward expansion
forms new chondrocytes,
feeds cartilage
Three types– REVIEW
STUDENTS DO

38. Growth of Cartilage Not in Mature Cartilage Types:
Appositional – from perichondrium
Interstitial – inside cartilage
Epiphysial Plate:

39. Bone Structure … Chemical Composition of Bone
Organic
Cells
Ground Substance
Proteoglycans & glycoproteins
Collagen Fibers
Osteoid = newly secreted Ground &
Collagen
Inorganic
Ca-Phosphate = hydroxyapatites = 65%

40. Figure 6.8 Endochondral ossification in a long bone.
Slide 2
Week 9
Hyaline
cartilage
Bone collar
Primary
ossification
center
Bone collar forms around the
diaphysis of the hyaline cartilage
model. 1
© 2013 Pearson Education, Inc.

41. Figure 6.8 Endochondral ossification in a long bone.
Slide 3
Area of deteriorating
cartilage matrix
Chondrocytes in shaft Hypertrophy
In middle:
Cartilage matrix calcifies
Chondrocytes die
Calcified matrix deteriorates
Rest of cartilage alive and mitotic
Cartilage in the center
of the diaphysis calcifies
and then develops cavities. 2
© 2013 Pearson Education, Inc.

42. Figure 6.8 Endochondral ossification in a long bone.
Slide 7
Week 9
Month 3
Birth
Childhood to
adolescence
Articular
cartilage
Secondary
ossification
center
Spongy
bone
Epiphyseal
blood vessel
Area of
deteriorating
cartilage matrix
Epiphyseal
plate
cartilage
Hyaline
cartilage
Spongy
bone
formation
Medullary
cavity
Bone collar
Blood
vessel of
periosteal
bud
Primary
ossification
center
Bone collar
forms around the
diaphysis of the
hyaline cartilage
model. 1
Cartilage in the
center of the
diaphysis calcifies
and then develops
cavities. 2
The periosteal
bud invades the
internal cavities
and spongy bone
forms. 3
The diaphysis
elongates and a
medullary cavity
forms. Secondary
ossification
centers appear in
the epiphyses. 4
The epiphyses
ossify. When
completed, hyaline
cartilage remains
only in the
epiphyseal plates
and articular
cartilages. 5
© 2013 Pearson Education, Inc.