Chapter 6

BONES AND BONE TISSUE


 

 

 


I.                    Skeletal Cartilage

 

·        The architecture of our skeleton is initially set up and composed of                          and                                                  ; although most of these early support structures are soon replaced by bone, some remain in regions that require more flexible, or resilient tissue.

 

A.     Basic Structure, Types and Locations

1. Characteristics of cartilage

 

a. perichondrium

 

b. chondrocyte

 

2. 3 types of cartilage

 

a.

 

b.

 

c.

 

1.      Growth of Cartilage

 

1.      Occurs in 2 ways

 

1.       

 

2.       

 

2.      Calcification of cartilage matrix

II.   Bone Functions

 

A.

 

B.

 

C.

 

D.

 

E.

 

III.  Classification of Bone

 

A.     Type

 

1.

 

2.

 

B.     Shape

 

1.

 

2.

 

a.sesamoid bones-

 

3.

 

4.

 

IV.  Bone Structure

 

1.      Gross Anatomy of a long bone

1. Diaphysis

 

 

2. Epiphysis

 

 

3. Articular cartilage

 

 

4. Epiphyseal plate/line

 

 

5. Periosteium

 

 

6. Osteoblasts

 

 

7. Osteoclasts

 

 

8. Endosteum

 

 

B. Typical Short, Irregular and Flat

 

1.      Share a simple design

 

 

2.      Diploë

 

 

C. Location of Hematopoietic Tissue in Bone

 

a.

 

 

b.

 

D. Microscopic Structure of Bone

 

1.      Compact bone

 

a. osteon or Haversian system

 

b. lamellae

 

c. central canal

 

d. volkmann’s canals

 

e. osteocytes

 

f. lacunae

 

g. canaliculi

 

 

2.      Spongy bone

 

a. trabeculae

 

E. Chemical Composition of Bone

 

1.      Organic components

 

a.

 

b.

 

2.      Inorganic components-

 

 

F.      Bone markings

 

 

V.     Bone Development

 

·        Osteogenesis or Ossification; defined as

 

 

 

A.     Formation of the Bony Skeleton

 

1. Intramembranous ossification

 

a.                                                  membranes serve as initial framework

 

b.      Steps involved:

 

(1)

 

(2)

 

(3)

 

(4)

c.       Final product??

 

2. Endochondral ossification

 

a.       Pattern established by                                    .

 

 

b.      Long bone, example

 

·        Set-up: involves 2 events

 

1.

 

2.

 

·        next, ossification occurs

 

1.

 

2.

 

3.

 

4.

 

5.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

B.     Bone Growth

 

1.      Longitudinal growth (bone length)

 

a.       Process occurring in epiphyseal plate:

 

1.

 

2.

 

3.

 

4.

 

 

b.      Epiphyseal plate closure

 

2.      Appositional growth (bone width)

 

a.       Process involves:

 

(1)

 

(2)

 

3.      Hormonal Regulation of Bone Growth

 

a.

 

b.

 

c.

 

 

VI.  Bone Homeostasis: Remodeling and Repair

 

A.     Bone Remodeling

 

1.      Basic process involves:

 

a.

 

b.

 

2. Control of Remodeling

 

a. Hormonal control

 

(1)

 

(2)

 

b. Mechanical stress

 

 

 

 

 

 

 

B.     Repair of Fractures

 

1.      Phases of Repair

 

a.

 

 

b.

 

 

c.

 

 

d.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

VII.  Homeostatic Bone Imbalances

 

1.      Osteoporosis

 

 

 

 

 

2.      Osteomalacia and Rickets

 

 

 

 

 

3.      Paget's Disease