What are the functions and the structure of bone?

Functions of Bones (textbook pages 176 & 177)

Bone Structure (textbook pages 179 – 184)

Skeletal System Phenomenon

Figure 6-18 The Effects of Osteoporosis on Spongy Bone

SEM × 25

Normal spongy bone

Spongy bone in osteoNormal spongy bone

porosis

SEM × 21

Label the following structures on the long bone

Learning Target 4f

4

A

​

I

​

H

​

J

L

K

D

B

C

​

Diaphysis

Proximal Epiphysis

Distal Epiphysis

Spongy bone

Compact bone

Medullary cavity

Epiphyseal line

Periosteum

Endosteum

Articular cartilage

​

Learning Target

4. I can describe the ANATOMY of the skeletal system.

e. I can name, identify (by microscopic observation), and describe the tissue types composing the skeleton.

f. I can label and describe the gross anatomy of a long bone.

5

Learning Target

4. I can describe the ANATOMY of the skeletal system.

g. I can describe the microscopic anatomy of compact bone and distinguish it from spongy bone.

h. I can identify the organic and inorganic components of bone and describe the contributions they make to bone.

​

6

Which of the following choices is NOT a FUNCTION of the skeletal system?

​

1. Blood cell formation
2. Movement
3. Protection
4. Triglyceride (fat) storage
5. Heat production

Learning Target 5b

7

What are the functions of bones?�(textbook pages 176 & 177, and RG for Chapter 6, page 7; #13)

• Support
• For body and soft organs

​

• Protection
• For brain, spinal cord, and vital organs

​

• Movement
• Levers for muscle action

​

• Mineral and growth factor storage
• Calcium and phosphorus, and growth factors reservoir

​

​

Learning Target 5b

8

What are the functions of bones?�(textbook pages 176 & 177, and RG for Chapter 6, page 7; #13)

• Blood cell formation (hematopoiesis) in red marrow cavities of certain bones

​

• Triglyceride (fat) storage in bone cavities
• Energy source

​

• Hormone production
• Osteocalcin
• Regulates bone formation
• Protects against obesity, glucose intolerance, diabetes mellitus

Learning Target 5b

9

What are bones?�(textbook page 177)

• 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

Learning Target 4

10

Where is compact bone located on the long bone?�

1. The inner lining of the bone
2. Outer layer of bone
3. Only on the epiphysis
4. Only in the diaphysis

How does the structure of compact bone differ from that of spongy bone? (textbook page 177)

• Compact bone
• Dense outer (superficial) layer of every bone
• Looks smooth and solid to naked eye

Learning Target 4g

12

Where is spongy bone found?

1. Surrounds to compact bone
2. Only found in children
3. Internal to compact bone
4. Outer layer of bone

​

​

What is the function of spongy bone?

How does the structure of compact bone differ from that of spongy bone? (textbook page 177)

• Spongy bone
• Internal (deep) to compact bone
• A honeycomb of small-needle-like or flat pieces called trabeculae (“little beams”)
• Open spaces between trabeculae filled with red or yellow marrow
• has blood vessels
• Forms red blood cells
• And supplies nutrients to osteocytes

​

​

Learning Target 4g

14

What is the structure of a long bone? (textbook pages 177 – 179)

• All long bones have the same general structure:
• a shaft,
• bone ends, and
• membranes.

Learning Target 4f

15

What is yellow marrow?

1. The location of blood cell production
2. Adipose tissue
3. A route for nerve supply
4. A protective covering of bone

Figure 6.4 The structure of a long bone.�(textbook page 180)

• Yellow Marrow
• adipose tissue
• can revert to red marrow when enhanced red blood cell production is needed

Learning Target 4f

17

G

D

E

​

F

​

Figure 6.4 The structure of a long bone.�(textbook page 180)

Learning Target 4f

18

E

​

D

​

F

G

H

D

Which structure is connective tissue covering on the outside of the diaphysis?

1. Articular cartilage
2. Endosteum
3. Periosteum
4. Sharpey’s fibers

​

​

What type of tissue is it made up of?

​

Figure 6.4 The structure of a long bone.�(textbook page 180)

• Periosteum
• double-layer membrane
• outer fibrous layer made of dense irregular connective tissue
• What do you think the function of this outer layer is? (Recall what DICT does.)

​

​

​

​

​

Learning Target 4f

20

G

D

E

​

F

​

Functions:

​

• Provides structural strength
• Resists pulling forces in many directions

​

​

​

​

​

​

Learning Target 4f

Figure 6.4 The structure of a long bone.�(textbook page 180)

• Periosteum
• double-layer membrane
• outer fibrous layer made of dense irregular connective tissue
• What do you think the function of this outer layer is? (Recall what DICT does.)
• inner layer consists of osteogenic cells
• stem cells that differentiate into osteoblasts, bone-forming cells
• Sharpey’s Fibers- anchor periosteum

Learning Target 4f & 5e

22

G

E

​

F

​

Figure 6.4 The structure of a long bone.�(textbook page 180)

• Periosteum
• Functions:
• Isolates bone from surrounding tissues
• Provides a route for circulatory and nervous supply
• Participates in bone growth and repair

​

Learning Target 4f & 5e

23

G

E

​

F

​

Figure 6.4 The structure of a long bone.�(textbook page 180)

• Endosteum
• lines internal bone surfaces
• lines the canals that pass through compact bone
• covers trabeculae of spongy bone
• contains osteogenic cells
• stem cells that differentiate into osteoblasts and osteoclasts, bone-forming cells and bone destroying cells

Learning Target 4f & 5e

24

G

Figure 6.4 The structure of a long bone.�(textbook page 180)

Learning Target 4f

25

I

​

H

​

J

L

K

Figure 6.4 The structure of a long bone.�(textbook page 180)

Learning Target 4f & g

26

​

​

trabeculae

(strut or thin plate of bone)

Where are blood cells produced?

1. Yellow bone marrow
2. The medullary cavity
3. Periosteum
4. Endosteum
5. Red bone marrow

Where is red marrow found?

1. Within the diaphysis
2. In spongy bone
3. In both compact and spongy bone
4. Within the medullary cavity

Figure 6.4 The structure of a long bone.�(textbook page 180)

• Red Marrow
• Typically, found in trabecular cavities of spongy bone
• In adults, red blood cell production occurs only in heads of the femur and humerus

​

​

• Functions in blood cell formation (hematopoiesis)

Learning Target 4f, g & 5d

29

trabecular cavities

Bone Marrow Transplants�(MedlinePlus, Bone marrow transplant)

• Red marrow in diploë (spongy bone) of flat bones and in some irregular bones (such as hip bone) is much more active in hematopoiesis.
• Red marrow is taken from these sites for transplantation.
• A bone marrow transplant is a procedure to replace damaged or destroyed bone marrow with healthy bone marrow stem cells.

Learning Target 8

30

Learning Target 8

31

Learning Target 8

32

Learning Target 8

33

Learning Target 8

34

An area made up of hyaline cartilage until growth ceases is called?

1. Articular cartilage
2. Epiphyseal plate
3. Epiphyseal line
4. Epiphyseal cartilage

Figure 6.4 The structure of a long bone.�(textbook page 180)

• Epiphyseal Line
• remnant of epiphyseal plate
• a disc of hyaline cartilage that grows during childhood to lengthen the bone

Learning Target 4f & 5c

36

L

K

Figure 6-11a Bone Growth at an Epiphyseal Cartilage

An x-ray of growing epiphyseal

cartilages (arrows)

Figure 6-11b Bone Growth at an Epiphyseal Cartilage

Epiphyseal lines in an

adult (arrows)

Which type of cartilage is found on the ends (epiphyses) of long bones?

1. Hyaline cartilage
2. Elastic cartilage
3. Fibrocartilage

​

Figure 6.4 The structure of a long bone.�(textbook page 180)

• Articular cartilage
• hyaline cartilage
• covers the bone ends at moveable joints

Learning Target 4f

40

L

Figure 6.7 Microscopic anatomy of compact bone. (textbook page 183)

• Osteon
• AKA, Haversian System
• structural unit of compact bone
• tiny weight-bearing pillar
• group of hollow tubes of bone matrix, one outside the next
• each matrix tube is a lamella

Learning Target 4g

41

A

B

B

C

C

Figure 6.7 Microscopic anatomy of compact bone. (textbook page 183)

• Central (Haversian) canal and Perforating (Volkmann’s) canals
• contain small blood vessels and nerve fibers
• serve the needs of the osteon’s cells

–Central – runs through the core of each osteon (parallel to the long axis of bone)

–Volkmann’s –runs perpendicular to the long axis of the bone

​

Learning Target 4g

42

C

C

Figure 6.7 Microscopic anatomy of compact bone. (textbook page 183)

• Osteocytes
• mature bone cells
• occupy lacunae (little hollows or spaces between lamellae)

​

Learning Target 4g & 5e

43

C

A

​

​

B

D

Microscopic Structure of Bone: Compact Bone

Figure 6.6a, b

Figure 6.7 Microscopic anatomy of compact bone. (textbook page 183)

• Osteocytes
• mature bone cells
• occupy lacunae at the junctions of lamellae
• Lamellae are:

•Tubes or layers of bone matrix

•maintain bone matrix

•sense bone deformation and damage

​

Learning Target 4g & 5e

45

C

D

Figure 6.7 Microscopic anatomy of compact bone. (textbook page 183)

• Canaliculi
• connect the lacunae to each other and to central canal
• tie all osteocytes in an osteon together
• permit nutrients and wastes to be relayed from one osteocyte to the next

Learning Target 4g & 5e

47

D

Microscopic Structure of Bone: Compact Bone

Figure 6.6a, b

Figure 6.7 Microscopic anatomy of compact bone. (textbook page 183)

Learning Target 4e & g

49

A

B

​

C

Description:

Hard, calcified matrix

Collagen fibers

Osteocytes in lacunae

Well vascularized

​

Function:

Supports & protects

Allows for movement

(provides levers for

muscles to act on)

Stores calcium & other

minerals and fat

Site of hematopoiesis

​

Location:

Bones

(textbook pages 137 & 138)

Learning Target 4e & g

A

​

B

​

C

​

What is the chemical composition of bone? (textbook pages 179 – 181 & 183)

• Bone has both organic and inorganic components
• Organic components include
• Cells
• osteoblasts – immature bone-building cells; make liquid and collagen fibers of matrix; “bone-building cells”
• osteocytes – mature bone cells; maintain bone matrix and sense bone deformation or damage
• osteoclasts – bone-destroying cells

Learning Target 4h & 5e

51

Bone (Osseous) Tissue

Homeostasis

Bone building (by ?) and bone recycling (by ?) must balance

• More breakdown than building, bones become weak
• Exercise, particularly weight-bearing exercise, causes osteoblasts to build bone
• What does this tell us about treatment of bone injuries?

What is the chemical composition of bone? (textbook pages 179 – 181 & 183)

• Organic components include
• Matrix – area of a tissue outside of cells
• A thick, liquid-like substance and
• Collagen fibers
• contributes to a bone’s flexibility
• great tensile strength allows the bone to resist stretch and twisting

Learning Target 4h

53

Figure 6-5b The Structure of Compact Bone

The orientation of collagen

fibers in adjacent lamellae

Collagen

fiber

orientation

What is the chemical composition of bone? (textbook pages 179 – 181 & 183)

• Inorganic components include mineral salts
• Calcium phosphates
• tiny crystals packed in and around collagen fibers
• account for bones’ (1) hardness and (2) ability to resist compression

Learning Target 4h

55

Chemical Composition of Bone�(READING GUIDE AND DATA SHEET for Overview of the Skeleton, page 5)

​

• READ page 84 of lab handout.

​

• RESPOND to #14a & b.

Learning Target 8

56

Chemical Composition of Bone�(READING GUIDE AND DATA SHEET for Overview of the Skeleton, page 5)

15. What happens to the HEATED bone when GENTLE pressure is applied?

​

• The bone breaks and small pieces crumble off.

​

• What happens to the bone TREATED WITH ACID when GENTLE pressure is applied?

Learning Target 8

57

Chemical Composition of Bone�(READING GUIDE AND DATA SHEET for Overview of the Skeleton, page 5)

17. Refer back to your answers to 14. What effect does HEAT appear to have on the chemical composition of bone that caused it to behave as described in 15?

​

• Refer back to your answers to 14. What effect does ACID appear to have on the chemical composition of bone that caused it to behave as described in 16?

Learning Target 8

58

Chemical Composition of Bone�(READING GUIDE AND DATA SHEET for Overview of the Skeleton, page 5)

19. Which demonstration specimen, heat- or acid-treated, best models the bones of a child with RICKETS? Research rickets and justify your answer. (textbook page 192) (LT 5i)

​

• Which demonstration specimen, heat- or acid-treated, best models the bones of a child with OSTEOPOROSIS? Research rickets and justify your answer. (textbook pages 192 & 193) (LT 5i)

Learning Target 5i

59

Long Bone Growth and Remodeling

Figure 6.10

• During infancy and childhood, epiphyseal plate activity is stimulated by growth hormone
• During puberty, testosterone and estrogens:
• Initially promote adolescent growth spurts
• Cause masculinization and feminization of specific parts of the skeleton
• Later induce epiphyseal plate closure, ending longitudinal bone growth

There are some cases in which the epiphyseal plate can close too early. What might the cause of this be?

Hormonal Regulation of Bone Growth During Youth

Figure 6-18 The Effects of Osteoporosis on Spongy Bone

SEM × 25

Normal spongy bone

Spongy bone in osteoporosis

SEM × 21

What are the structural and functional properties of the three types of cartilage?

Skeletal Cartilages (textbook pages 173 & 174)

Cartilage (textbook pages 132, & 134 – 136)

Learning Targets

4. I can describe the ANATOMY of the skeletal system.

e. I can name, identify (by microscopic observation), and describe the tissue types composing the skeleton (osseous, hyaline cartilage, elastic cartilage, and fibrocartilage).

5. I can explain the PHYSIOLOGY of the skeletal system.

b. I can describe the functions of cartilage and bone (osseous) tissues.

​

64

What are the structures and functions of the three types of cartilage?�(textbook pages 132, 173 & 174)

• Cartilage tissue
• consists primarily of water
• accounts for its resilience (ability to spring back)
• contains no nerves or blood vessels
• surrounded by perichondrium
• composed of dense irregular connective tissue
• What is the function of dense irregular connective tissue?

65

Learning Target 4e

66

Functions:

​

• Provides structural strength
• Resists pulling forces in many directions

​

​

​

​

​

​

Learning Target 4e

What are the structures and functions of the three types of cartilage?�(textbook pages 132, 173 & 174)

• Cartilage tissue
• consists primarily of water
• accounts for its resilience (ability to spring back)
• contains no nerves or blood vessels
• surrounded by perichondrium
• composed of dense irregular connective tissue
• resists outward expansion when the cartilage is compressed
• contains blood vessels from which nutrients diffuse to cartilage cells

​

67

Learning Target 4e

What are the structures and functions of the three types of cartilage?�(textbook pages 173, 174, 134 & 135)

• Types of Cartilage

​

• Hyaline, Elastic, Fibrocartilage

​

• Basic components
• cells called chondrocytes (cartilage cells)
• chondrocytes encased in lacunae (small cavities)
• non-living, jellylike extracellular matrix surrounds/separates chondrocytes in their lacunae

68

Learning Target 4e

Figure 6.1 The bones and cartilages of the human skeleton (textbook page, 175)

69

Learning Target 4e

70

Description:

Firm matrix

Collagen fibers

(imperceptible)

Chondrocytes in lacunae

Not vascularized

​

Function:

Supports & reinforces

Cushions

Resists compression

​

Location:

Embryonic skeleton

Articular cartilages of

bones at moveable joints

Costal cartilages of ribs

Nose, trachea, larynx

(textbook pages 134 & 135)

Learning Target 4e & 5b

71

Description:

Similar to hyaline

cartilage

More elastic fibers in

matrix

​

Function:

Maintains structure and

shape

Allows great flexibility

​

Location:

External ear

Epiglottis

(textbook pages 134 & 135)

Learning Target 4e & 5b

72

Description:

Similar to hyaline

cartilage with less

firm matrix

Thick collagen fibers

​

Function:

Resists stretching

(great tensile

strength)

Absorbs compressive

shock

​

Location:

Intervertebral discs

(menisci)

Pubic symphysis

Discs of knee joints

(textbook pages 134 & 136)

Learning Target 4e & 5b

1. Which of the following is a basic component of cartilages?

1. periosteum
2. osteocyte
3. endosteum
4. chondrocyte

73

Learning Target 4e

2. Which of the following types of cartilage is/are correctly matched to their descriptions?

1. elastic – firm matrix with imperceptible collagen fibers
2. fibrocartilage - less firm matrix with thick collagen fibers
3. hyaline – firm matrix with elastic fibers

74

Learning Target 4e

3. Which of the following photomicrographs shows ELASTIC cartilage?

75

Learning Target 4e

4. Which of the following types of cartilage is correctly paired with where it is located?

1. elastic – epiglottis
2. fibrocartilage – discs (menisci) of knees
3. hyaline – external ear

76

Learning Target 4e

5. The pubic symphysis is comprised of which of the following types of cartilage?

77

Learning Target 4e

Bone Homeostasis:�Remodeling and Repair

Learning Target 5h. I can classify fractures and describe the physiology of fracture repair.

(textbook pages 187 – 193)

Which of the following statements accurately describes bone remodeling?

​

1. Bone deposit and bone resorption occur at the surfaces of the periosteum and endosteum.

​

• Osteclasts deposit bone.

​

• Osteoblasts resorb bone.

​

• Remodeling is regulated by the homeostatic control of blood levels of calcium and mechanical and gravitational forces.

READING GUIDE for Bone Homeostasis,

page 1; #3, 4 & 7

Bone Homeostasis: Bone Remodeling�(textbook pages 187 – 191)

• Bone remodeling – process involving bone formation and destruction in response to hormonal and mechanical factors

​

• Consists of both bone deposit and bone resorption

​

• Occurs at surfaces of both periosteum and endosteum

​

• Remodeling units – Adjacent osteoblasts and osteoclasts

​

READING GUIDE for Bone Homeostasis,

page 1; #3 & 4

Bone Deposit�(textbook page 187)

• Occurs wherever bone is injured or added bone strength is required

​

• Is the function of osteoblasts

© 2013 Pearson Education, Inc.

READING GUIDE for Bone Homeostasis,

page 1; #4 a & 5a

Bone Resorption�(textbook page 187)

• Is the function of osteoclasts
• Dig depressions or grooves as break down matrix
• Secrete lysosomal enzymes that digest matrix
• Acidity converts calcium salts to soluble forms

​

• Osteoclasts also
• Phagocytize demineralized matrix and dead osteocytes
• Once resorption complete, osteoclasts undergo apoptosis

​

• Osteoclast activation involves PTH

READING GUIDE for Bone Homeostasis,

page 1; #6

1. Which of the following statements accurately describes bone remodeling?

​

1. Bone deposit and bone resorption occur at the surfaces of the periosteum and endosteum.

​

• Osteclasts deposit bone.

​

• Osteoblasts resorb bone.

​

• Remodeling is regulated by the homeostatic control of blood levels of calcium and mechanical and gravitational forces.

READING GUIDE for Bone Homeostasis,

page 1; #3, 4 & 7

2. Which of the following statements about the hormonal control of blood calcium levels is TRUE?

​

1. Calcium makes bones hard and able to resist compression.

​

• Calcium is absorbed from the intestine under the control of vitamin D.

​

• Regulation of blood calcium levels is a negative feedback mechanism.

​

• Parathyroid hormone (PTH) released in response to low calcium levels signals osteoclasts to break down bone and to release calcium into the blood.

READING GUIDE for Bone Homeostasis,

page 2; #8, 10 – 12

Control of Remodeling�(textbook pages 187 - 192)

• Occurs continuously but regulated by genetic factors and two control loops
• Negative feedback hormonal loop for Ca²⁺ homeostasis
• Controls blood Ca²⁺ levels; NOT skeleton’s strength or well-being
• Recall, mineral and growth factor storage is one function of bones
• Responses to mechanical and gravitational forces

​

READING GUIDE for Bone Homeostasis,

page 1; #7

Importance of Calcium�(textbook page 187)

• Functions in
• Nerve impulse transmission
• Muscle contraction
• Blood coagulation
• Secretion by glands and nerve cells
• Cell division
• 1200 – 1400 grams of calcium in body
• 99% as bone minerals
• Amount in blood tightly regulated (9-11 mg/dl)
• Intestinal absorption requires Vitamin D metabolites
• Dietary intake required

READING GUIDE for Bone Homeostasis,

page 2; #8 – 10

Hormonal Control of Blood Ca^2+�(textbook pages 187 & 188)

• Parathyroid hormone (PTH)
• Produced by parathyroid glands
• Removes calcium from bone regardless of bone integrity (strength/well-being)

​

• Calcitonin may be involved
• In high doses lowers blood calcium levels temporarily

​

READING GUIDE for Bone Homeostasis,

page 2; #11

Negative Feedback Hormonal Loop for blood Ca²⁺ Homeostasis�(textbook pages 187 & 188)

Controlled by parathyroid hormone (PTH)

↓ Blood Ca²+ levels

↓

PTH release

↓

PTH stimulates osteoclasts to degrade bone matrix, releasing Ca²⁺

↓

• Blood Ca²⁺ levels

↓

PTH release ends

READING GUIDE for Bone Homeostasis,

page 2; #12

2. Which of the following statements about the hormonal control of blood calcium levels is TRUE?

​

1. Calcium makes bones hard and able to resist compression.

​

• Calcium is absorbed from the intestine under the control of vitamin D.

​

• Regulation of blood calcium levels is a negative feedback mechanism.

​

• Parathyroid hormone (PTH) released in response to low calcium levels signals osteoclasts to break down bone and to release calcium into the blood.

READING GUIDE for Bone Homeostasis,

page 2; #8, 10 – 12

Calcium Homeostasis�(textbook page 188)

• Even minute changes in blood calcium dangerous
• Severe neuromuscular problems
• Hyperexcitability (levels too low)
• Nonresponsiveness (levels too high)
• Hypercalcemia
• Sustained high blood calcium levels
• Deposits of calcium salts in blood vessels, kidneys can interfere with function

Bone Homeostasis: Response to Mechanical Stress

• Bones reflect stresses they encounter
• Long bones thickest midway along diaphysis where bending stresses greatest
• Bones stressed when weight bears on them or muscles pull on them
• Usually off center so tends to bend bones
• Bending compresses on one side; stretches on other

READING GUIDE for Bone Homeostasis,

page 2; #13

Figure 6.13 Bone anatomy and bending stress.

Load here

(body weight)

Head of

femur

Compression

here

Point of

no stress

Tension

here

Results of Mechanical Stressors: Wolff's Law

• Bones grow or remodel in response to demands placed on it
• Explains
• Handedness (right or left handed) results in thicker and stronger bone of that upper limb
• Curved bones thickest where most likely to buckle
• Trabeculae form trusses along lines of stress
• Large, bony projections occur where heavy, active muscles attach
• Bones of fetus and bedridden featureless

READING GUIDE for Bone Homeostasis,

page 2; #13

What do you think?

• Using Wolff’s Law …..what would you say?

Your mother is concerned about osteoporosis in her future so the doctor tells her to begin exercising daily. What type of exercise would you recommend?

• Weight Training?
• Swimming?
• Jogging?

​

How Mechanical Stress Causes Remodeling�(textbook pages 188 – 191)

• Electrical signals produced by deforming bone may cause remodeling
• Compressed and stretched regions oppositely charged
• Fluid flows within canaliculi appear to provide remodeling stimulus

READING GUIDE for Bone Homeostasis,

page 2; #14

Results of Hormonal and� Mechanical Influences�(textbook page 189)

• Hormonal controls determine whether and when remodeling occurs to changing blood calcium levels
• Mechanical stress determines where remodeling occurs

Bone Repair�(textbook pages 191 & 192)

• Fractures – breaks
• Youth
• Most result from trauma
• Old age
• Most result of weakness from bone thinning

READING GUIDE for Bone Homeostasis,

page 3; #15 & 16

Classify the fracture below.�(textbook pages 190 & 191)

• Displaced or Nondisplaced?
• nondisplaced
• Complete or Incomplete?
• complete
• Linear, Oblique, or Transverse?
• oblique
• Compound or Simple?
• simple
• Fracture Type?
• comminuted

Classify the fracture below.�(textbook pages 190 & 191)

• Displaced or Nondisplaced?
• nondisplaced
• Complete or Incomplete?
• complete
• Linear, Oblique, or Transverse?
• oblique/transverse
• Compound or Simple?
• simple
• Fracture Type?
• compression

Classify the fracture below.�(textbook pages 190 & 191)

• Displaced or Nondisplaced?
• nondisplaced
• Complete or Incomplete?
• complete
• Linear, Oblique, or Transverse?
• oblique
• Compound or Simple?
• simple
• Fracture Type?
• spiral

Classify the fracture below.�(textbook pages 190 & 191)

• Displaced or Nondisplaced?
• displaced
• Complete or Incomplete?
• complete
• Linear, Oblique, or Transverse?
• transverse
• Compound or Simple?
• simple
• Fracture Type?
• epiphyseal

Classify the fracture below.�(textbook pages 190 & 191)

• Displaced or Nondisplaced?
• displaced
• Complete or Incomplete?
• complete
• Linear, Oblique, or Transverse?
• ?
• Compound or Simple?
• simple
• Fracture Type?
• depression

Classify the fracture below.�(textbook pages 190 & 191)

• Displaced or Nondisplaced?
• nondisplaced
• Complete or Incomplete?
• incomplete
• Linear, Oblique, or Transverse?
• oblique
• Compound or Simple?
• simple
• Fracture Type?
• greenstick

Bone Repair – Stages in the Healing of a Bone Fracture�(textbook pages 191 – 192)

Stage 1 – Hematoma Formation

Bone Repair Stage 1

Stage 2 – Fibrocartilaginous Callus Formation

Stage 2 – Fibrocartilaginous Callus Formation�VOCABULARY

• Callus – a localized thickening

​

• Granulation tissue
• tissue that forms at the site of injury
• contains capillaries that grow in from near by areas

Stage 2 – Fibrocartilaginous Callus Formation�VOCABULARY

• Phagocytes – cells (derived from white blood cells) that remove cellular debris and attack and remove foreign compounds or pathogens by phagocytosis

Stage 2 – Fibrocartilaginous Callus Formation�VOCABULARY

• Fibroblast – young actively dividing cell that forms connective tissue
• (bone repair) dense irregular connective tissue of periosteum and endosteum involved
• collagen fibers are produced

Bone Repair Stage 2

Stage 3 – Bony Callus Formation

Bone Repair Stage 3

Stage 4 – Bone Remodeling

Bone Repair Stage 4

Please get out a piece of notebook paper

3. Arrange the following stages in the healing of a bone fracture in order from first to last to occur.

1. Bony callus formation
2. Bone remodeling
3. Fibrocartilaginous callus formation
4. Hematoma formation

1. 1, 2, 3, 4
2. 3, 1, 2, 4
3. 4, 1, 3, 2
4. 4, 3, 1, 2

READING GUIDE for Bone Homeostasis, page 4; #19

4. Arrange the following figures of the stages in the healing of a bone fracture in order from first to last to occur.

1. 1, 3, 2, 4
2. 1, 2, 4, 3
3. 2, 4, 3, 1
4. 2, 3, 4, 1

READING GUIDE for Bone Homeostasis, page 4; #19

1.

4.

3.

2.

5. Which of the following figures of the stages in the healing of a bone fracture is correctly labeled?

READING GUIDE for Bone Homeostasis, page 4; #19

A. Fibrocartilaginous callus formation

D. Hematoma formation

C. Bone remodeling

B. Bony callus formation

6. Which of the following stages in the healing of a bone fracture is correctly paired with its description?

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1. Hematoma formation – excess material on exterior and interior is removed; compact bone reconstructs shaft walls

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• Fibrocartilaginous callus formation – capillaries grow into the hematoma and phagocytic cells clean up debris; collagen and spongy bone begin to be produced

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• Bony callus formation – blood vessels tear and hemorrhage causing a blood clot; site becomes swollen, painful, and inflamed

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• Bone remodeling – bone trabeculae begin to appear; firm union forms in about two months

READING GUIDE for Bone Homeostasis, page 4; #19

7. Arrange the following EVENTS of HEMATOMA FORMATION in order from first to last to occur.

1. Blood vessels tear and hemorrhage
2. Hematoma (mass of clotted blood) forms
3. Bone cells die
4. Swelling, pain, and inflammation occur

1. 1, 2, 3, 4
2. 3, 1, 2, 4
3. 4, 1, 3, 2
4. 4, 3, 1, 2

READING GUIDE for Bone Homeostasis, page 4; #19

8. Arrange the following EVENTS of FIBROCARTILAGINOUS CALLUS FORMATION in order from first to last to occur.

1. Capillaries grow into hematoma
2. Collagen fibers span the break and connect the broken bone ends
3. Phagocytes clean up debris
4. Osteoblasts form spongy bone
5. Splint formed

1. 1, 2, 3, 4, 5
2. 1, 3, 2, 4, 5
3. 3, 1, 2, 4, 5
4. 3, 1, 2, 5, 4

READING GUIDE for Bone Homeostasis, page 4; #19

9. Arrange the following EVENTS of BONY CALLUS FORMATION in order from first to last to occur.

1. Fibrocartilaginous callus converted to bony callus
2. Firm union between bone ends forms within two months
3. Trabeculae form

1. 1, 2, 3
2. 1, 3, 2
3. 3, 2, 1,
4. 3, 1, 2

READING GUIDE for Bone Homeostasis, page 4; #19

10. Arrange the following EVENTS of BONE REMODELING in order from first to last to occur.

1. Compact bone reconstructs shaft walls
2. Excess bone material removed from exterior and interior of diaphysis
3. Mechanical stressors mold bony region

1. 1, 2, 3
2. 1, 3, 2
3. 2, 1, 3,
4. 2, 3, 1

READING GUIDE for Bone Homeostasis, page 4; #19

Answers for # – 10

Fracture Treatment and Repair

• Treatment
• Reduction
• Realignment of broken bone ends
• Closed reduction – physician manipulates to correct position
• Open reduction – surgical pins or wires secure ends
• Immobilization by cast or traction for healing
• Depends on break severity, bone broken, and age of patient

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READING GUIDE for Bone Homeostasis,

page 3; #18

Homeostatic Imbalances

• Rickets
• Bones of children are inadequately mineralized causing softened, weakened bones
• Bowed legs and deformities of the pelvis, skull, and rib cage are common
• Caused by insufficient calcium in the diet, or by vitamin D deficiency

Homeostatic Imbalances

• Osteoporosis
• Group of diseases in which bone reabsorption outpaces bone deposit
• Spongy bone of the spine is most vulnerable
• Occurs most often in postmenopausal women
• Bones become so fragile that sneezing or stepping off a curb can cause fractures

Osteoporosis: Treatment

• Calcium and vitamin D supplements
• Increased weight-bearing exercise
• Hormone (estrogen) replacement therapy (HRT) slows bone loss
• Natural progesterone cream prompts new bone growth