1. 2 Support and Movement Fundamentals of Anatomy & Physiology Unit
Frederic H. Martini
PowerPoint® Lecture Slides prepared by Professor Albia Dugger, Miami–Dade College, Miami, FL
Professor Robert R. Speed, Ph.D., Wallace Community College, Dothan, AL
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings

2. Chapter 6: Osseous Tissue and Bone Structure

3. The Skeletal System Skeletal system includes: bones of the skeleton
cartilages, ligaments, and connective tissues

4. What are the functions of the skeletal system?

5. Functions of the Skeletal System
Support
Storage of minerals (calcium)
Storage of lipids (yellow marrow)

6. Functions of the Skeletal System
Blood cell production (red marrow)
Protection
Leverage (force of motion)

7. How are bones classified?

8. Classification of Bones
Bones are identified by:
shape
internal tissues
bone markings

9. Bone Shapes Long bones Flat bones Sutural bones Irregular bones
Short bones
Sesamoid bones

10. Long Bones
Figure 6–1a

11. Long Bones Are long and thin
Are found in arms, legs, hands, feet, fingers, and toes

12. Flat Bones
Figure 6–1b

13. Flat Bones Are thin with parallel surfaces
Are found in the skull, sternum, ribs, and scapula

14. Sutural Bones
Figure 6–1c

15. Sutural Bones Are small, irregular bones
Are found between the flat bones of the skull

16. Irregular Bones
Figure 6–1d

17. Irregular Bones Have complex shapes Examples: spinal vertebrae
pelvic bones

18. Short Bones
Figure 6–1e

19. Short Bones
Are small and thick
Examples:
ankle
wrist bones

20. Sesamoid Bones
Figure 6–1f

21. Sesamoid Bones Are small and flat
Develop inside tendons near joints of knees, hands, and feet

22. Bone Markings Depressions or grooves: Projections: Tunnels:
along bone surface
Projections:
where tendons and ligaments attach
at articulations with other bones
Tunnels:
where blood and nerves enter bone

23. Bone Markings
Table 6–1 (1 of 2)

24. Bone Markings
Table 6–1 (2 of 2)

25. Long Bones
The femur
Figure 6–2a

26. Long Bones Diaphysis: Epiphysis: Metaphysis: the shaft
wide part at each end
articulation with other bones
Metaphysis:
where diaphysis and epiphysis meet

27. The Diaphysis A heavy wall of compact bone, or dense bone
A central space called marrow cavity

28. The Epiphysis Mostly spongy (cancellous) bone
Covered with compact bone (cortex)

29. Flat Bones
The parietal bone of the skull
Figure 6–2b

30. Flat Bones Resembles a sandwich of spongy bone
Between 2 layers of compact bone

31. What are the types and functions of bone cells?

32. Bone (Osseous) Tissue Dense, supportive connective tissue
Contains specialized cells
Produces solid matrix of calcium salt deposits
Around collagen fibers

33. Characteristics of Bone Tissue
Dense matrix, containing:
deposits of calcium salts
bone cells within lacunae organized around blood vessels

34. Characteristics of Bone Tissue
Canaliculi:
form pathways for blood vessels
exchange nutrients and wastes

35. Characteristics of Bone Tissue
Periosteum:
covers outer surfaces of bones
consist of outer fibrous and inner cellular layers

36. Matrix Minerals 2/3 of bone matrix is calcium phosphate, Ca3(PO4)2:
reacts with calcium hydroxide, Ca(OH)2
to form crystals of hydroxyapatite, Ca10(PO4)6(OH)2
which incorporates other calcium salts and ions

37. Matrix Proteins
1/3 of bone matrix is protein fibers (collagen)

38. Bone Cells Make up only 2% of bone mass: osteocytes osteoblasts
osteoprogenitor cells
osteoclasts

39. Osteocytes Mature bone cells that maintain the bone matrix
Figure 6–3 (1 of 4)

40. Osteocytes Live in lacunae Are between layers (lamellae) of matrix
Connect by cytoplasmic extensions through canaliculi in lamellae
Do not divide

41. Osteocyte Functions To maintain protein and mineral content of matrix
To help repair damaged bone

42. Osteoblasts
Immature bone cells that secrete matrix compounds (osteogenesis)
Figure 6–3 (2 of 4)

43. Osteoid
Matrix produced by osteoblasts, but not yet calcified to form bone
Osteoblasts surrounded by bone become osteocytes

44. Osteoprogenitor Cells
Mesenchymal stem cells that divide to produce osteoblasts
Figure 6–3 (3 of 4)

45. Osteoprogenitor Cells
Are located in inner, cellular layer of periosteum (endosteum)
The endosteum is a thin layer of connective tissue which lines the surface of the bony tissue that forms the medullary cavity of long bones.
This endosteal surface is usually resorbed during long periods of malnutrition
Assist in fracture repair

46. Osteoclasts Secrete acids and protein-digesting enzymes
Figure 6–3 (4 of 4)

47. Osteoclasts Giant, mutlinucleate cells
Dissolve bone matrix and release stored minerals (osteolysis)
Are derived from stem cells that produce macrophages

48. Homeostasis
Bone building (by osteoblasts) and bone recycling (by osteoclasts) must balance:
more breakdown than building, bones become weak
exercise causes osteocytes to build bone

49. What is the difference between compact bone and spongy bone?

50. Compact Bone
Figure 6–5

51. Osteon The basic (smallest) unit of mature compact bone
Osteocytes are arranged in concentric lamellae
Around a central canal containing blood vessels

52. Perforating Canals Perpendicular to the central canal
Carry blood vessels into bone and marrow

53. Circumferential Lamellae
Lamellae wrapped around the long bone
Binds osteons together

54. Spongy Bone
Figure 6–6

55. Spongy Bone Does not have osteons
The matrix forms an open network of trabeculae
Trabeculae have no blood vessels

56. Red Marrow
The space between trabeculae is filled with red bone marrow:
which has blood vessels
forms red blood cells
and supplies nutrients to osteocytes

57. Yellow Marrow In some bones, spongy bone holds yellow bone marrow:
is yellow because it stores fat

58. Weight–Bearing Bones
Figure 6–7

59. Weight–Bearing Bones
The femur transfers weight from hip joint to knee joint:
causing tension on the lateral side of the shaft
and compression on the medial side

60. Periosteum and Endosteum
Compact bone is covered with membrane:
periosteum on the outside
endosteum on the inside

61. Periosteum
Figure 6–8a

62. Periosteum Covers all bones: It is made up of:
except parts enclosed in joint capsules
It is made up of:
an outer, fibrous layer
and an inner, cellular layer

63. Perforating Fibers Collagen fibers of the periosteum:
connect with collagen fibers in bone
and with fibers of joint capsules, attached tendons, and ligaments

64. Functions of Periosteum
Isolate bone from surrounding tissues
Provide a route for circulatory and nervous supply
Participate in bone growth and repair

65. Endosteum
Figure 6–8b

66. Endosteum An incomplete cellular layer: lines the marrow cavity
covers trabeculae of spongy bone
lines central canals

67. Endosteum Contains osteoblasts, osteoprogenitor cells, and osteoclasts
Is active in bone growth and repair

68. What is the difference between intramembranous ossification and endochondral ossification?

69. Bone Development Human bones grow until about age 25 Osteogenesis:
bone formation
Ossification:
the process of replacing other tissues with bone

70. Calcification The process of depositing calcium salts
Occurs during bone ossification and in other tissues

71. Ossification The 2 main forms of ossification are:
intramembranous ossification
endochondral ossification

72. Intramembranous Ossification
Also called dermal ossification:
because it occurs in the dermis
produces dermal bones such as mandible and clavicle
There are 3 main steps in intramembranous ossification

73. Intramembranous Ossification: Step 1
Figure 6–11 (Step 1)

74. Intramembranous Ossification: Step 1
Mesenchymal cells aggregate:
differentiate into osteoblasts
begin ossification at the ossification center
develop projections called spicules

75. Intramembranous Ossification: Step 2
Figure 6–11 (Step 2)

76. Intramembranous Ossification: Step 2
Blood vessels grow into the area:
to supply the osteoblasts
Spicules connect:
trapping blood vessels inside bone

77. Intramembranous Ossification: Step 3
Figure 6–11 (Step 3)

78. Intramembranous Ossification: Step 3
Spongy bone develops and is remodeled into:
osteons of compact bone
periosteum
or marrow cavities

79. Endochondral Ossification
Ossifies bones that originate as hyaline cartilage
Most bones originate as hyaline cartilage

80. How does bone form and grow?

81. Endochondral Ossification
Growth and ossification of long bones occurs in 6 steps

82. Endochondral Ossification: Step 1
Chondrocytes in the center of hyaline cartilage:
enlarge
form struts and calcify
die, leaving cavities in cartilage
Figure 6–9 (Step 1)

83. Endochondral Ossification: Step 2
Figure 6–9 (Step 2)

84. Endochondral Ossification: Step 2
Blood vessels grow around the edges of the cartilage
Cells in the perichondrium change to osteoblasts:
producing a layer of superficial bone around the shaft which will continue to grow and become compact bone (appositional growth)

85. Endochondral Ossification: Step 3
Blood vessels enter the cartilage:
bringing fibroblasts that become osteoblasts
spongy bone develops at the primary ossification center
Figure 6–9 (Step 3)

86. Endochondral Ossification: Step 4
Remodeling creates a marrow cavity:
bone replaces cartilage at the metaphyses
Figure 6–9 (Step 4)

87. Endochondral Ossification: Step 5
Capillaries and osteoblasts enter the epiphyses:
creating secondary ossification centers
Figure 6–9 (Step 5)

88. Endochondral Ossification: Step 6
Figure 6–9 (Step 6)

89. Endochondral Ossification: Step 6
Epiphyses fill with spongy bone:
cartilage within the joint cavity is articulation cartilage
cartilage at the metaphysis is epiphyseal cartilage

90. Endochondral Ossification
Appositional growth:
compact bone thickens and strengthens long bone with layers of circumferential lamellae
PLAY
Endochondral Ossification
Figure 6–9 (Step 2)

91. What are the characteristics of adult bones?

92. Epiphyseal Lines
Figure 6–10

93. Epiphyseal Lines When long bone stops growing, after puberty:
epiphyseal cartilage disappears
is visible on X-rays as an epiphyseal line

94. Mature Bones As long bone matures: osteoclasts enlarge marrow cavity
osteons form around blood vessels in compact bone

95. Blood Supply of Mature Bones
3 major sets of blood vessels develop
Figure 6–12

96. Blood Vessels of Mature Bones
Nutrient artery and vein:
a single pair of large blood vessels
enter the diaphysis through the nutrient foramen
femur has more than 1 pair

97. Blood Vessels of Mature Bones
Metaphyseal vessels:
supply the epiphyseal cartilage
where bone growth occurs

98. Blood Vessels of Mature Bones
Periosteal vessels provide:
blood to superficial osteons
secondary ossification centers

99. Lymph and Nerves The periosteum also contains:
networks of lymphatic vessels
sensory nerves

100. How does the skeletal system remodel and maintain homeostasis, and what are the effects of nutrition, hormones, exercise, and aging on bone?

101. Remodeling The adult skeleton: Remodeling: maintains itself
replaces mineral reserves
Remodeling:
recycles and renews bone matrix
involves osteocytes, osteoblasts, and osteoclasts

102. KEY CONCEPTS Bone continually remodels, recycles, and replaces
Turnover rate varies
If deposition is greater than removal, bones get stronger
If removal is faster than replacement, bones get weaker

103. Effects of Exercise on Bone
Mineral recycling allows bones to adapt to stress
Heavily stressed bones become thicker and stronger

104. Bone Degeneration Bone degenerates quickly
Up to 1/3 of bone mass can be lost in a few weeks of inactivity

105. KEY CONCEPTS What you don’t use, you lose
Stresses applied to bones during physical activity are essential to maintain bone strength and mass

106. Effects of Hormones and Nutrition on Bone
Normal bone growth and maintenance requires nutritional and hormonal factors

107. Minerals A dietary source of calcium and phosphate salts:
plus small amounts of magnesium, fluoride, iron, and manganese

108. Calcitriol The hormone calcitriol: is made in the kidneys
helps absorb calcium and phosphorus from digestive tract
synthesis requires vitamin D3 (cholecalciferol)

109. Vitamins
Vitamin C is required for collagen synthesis, and stimulates osteoblast differentiation
Vitamin A stimulates osteoblast activity
Vitamins K and B12 help synthesize bone proteins

110. Other Hormones Growth hormone and thyroxine stimulate bone growth
Estrogens and androgens stimulate osteoblasts
Calcitonin and parathyroid hormone regulate calcium and phosphate levels

111. Hormones for Bone Growth and Maintenance
Table 6–2

112. The Skeleton as Calcium Reserve
Bones store calcium and other minerals
Calcium is the most abundant mineral in the body

113. Chemical Composition of Bone
Figure 6–13

114. Functions of Calcium Calcium ions are vital to: membranes neurons
muscle cells, especially heart cells

115. Calcium Regulation Calcium ions in body fluids:
must be closely regulated
Homeostasis is maintained:
by calcitonin and parathyroid hormone
which control storage, absorption, and excretion

116. Calcitonin and Parathyroid Hormone Control
Bones:
where calcium is stored
Digestive tract:
where calcium is absorbed
Kidneys:
where calcium is excreted

117. Parathyroid Hormone (PTH)
Figure 6–14a

118. Parathyroid Hormone (PTH)
Produced by parathyroid glands in neck
Increases calcium ion levels by:
stimulating osteoclasts
increasing intestinal absorption of calcium
decreases calcium excretion at kidneys

119. Calcitonin
Figure 6–14b

120. Calcitonin Secreted by C cells (parafollicular cells) in thyroid
Decreases calcium ion levels by:
inhibiting osteoclast activity
increasing calcium excretion at kidneys

121. KEY CONCEPTS Calcium and phosphate ions in blood are lost in urine
Ions must be replaced to maintain homeostasis
If not obtained from diet, ions are removed from the skeleton, weakening bones
Exercise and nutrition keep bones strong

122. What are the types of fractures, and how do they heal?

123. Fractures Fractures: Fractures are repaired in 4 steps
cracks or breaks in bones
caused by physical stress
Fractures are repaired in 4 steps

124. Fracture Repair: Step 1
Figure 6–15 (Step 1)

125. Fracture Repair: Step 1 Bleeding: Bone cells in the area die
produces a clot (fracture hematoma)
establishes a fibrous network
Bone cells in the area die

126. Fracture Repair: Step 2
Figure 6–15 (Step 2)

127. Fracture Repair: Step 2 Cells of the endosteum and periosteum:
Divide and migrate into fracture zone
Calluses stabilize the break:
external callus of cartilage and bone surrounds break
internal callus develops in marrow cavity

128. Fracture Repair: Step 3
Figure 6–15 (Step 3)

129. Fracture Repair: Step 3 Osteoblasts:
replace central cartilage of external callus
with spongy bone

130. Fracture Repair: Step 4
Figure 6–15 (Step 4)

131. Fracture Repair: Step 4
Osteoblasts and osteocytes remodel the fracture for up to a year:
reducing bone calluses
PLAY
Steps in the Repair of a Fracture

132. The Major Types of Fractures
Pott’s fracture
Figure 6–16 (1 of 9)

133. The Major Types of Fractures
Comminuted fractures
Figure 6–16 (2 of 9)

134. The Major Types of Fractures
Transverse fractures
Figure 6–16 (3 of 9)

135. The Major Types of Fractures
Spiral fractures
Figure 6–16 (4 of 9)

136. The Major Types of Fractures
Displaced fractures
Figure 6–16 (5 of 9)

137. The Major Types of Fractures
Colles’ fracture
Figure 6–16 (6 of 9)

138. The Major Types of Fractures
Greenstick fracture
Figure 6–16 (7 of 9)

139. The Major Types of Fractures
Epiphyseal fractures
Figure 6–16 (8 of 9)

140. The Major Types of Fractures
Compression fractures
Figure 6–16 (9 of 9)

141. What are the effects of aging on the skeletal system?

142. Age and Bones Bones become thinner and weaker with age
Osteopenia begins between ages 30 and 40
Women lose 8% of bone mass per decade, men 3%

143. Effects of Bone Loss
The epiphyses, vertebrae, and jaws are most affected:
resulting in fragile limbs
reduction in height
tooth loss

144. Osteoporosis Severe bone loss Affects normal function
Over age 45, occurs in:
29% of women
18% of men

145. Hormones and Bone Loss Estrogens and androgens help maintain bone mass
Bone loss in women accelerates after menopause

146. Cancer and Bone Loss
Cancerous tissues release osteoclast-activating factor:
that stimulates osteoclasts
and produces severe osteoporosis

147. SUMMARY (1 of 5) Bone shapes, markings, and structure
The matrix of osseous tissue
Types of bone cells

148. SUMMARY (2 of 5) The structures of compact bone
The structures of spongy bone
The periosteum and endosteum

149. SUMMARY (3 of 5) Ossification and calcification
Intramembranous ossification
Endochondrial ossification

150. SUMMARY (4 of 5) Blood and nerve supplies
Bone minerals, recycling, and remodeling
The effects of exercise

151. SUMMARY (5 of 5) Hormones and nutrition Calcium storage
Fracture repair
The effects of aging