Bone formation Flashcards Preview

Year 1 Cell Biology > Bone formation > Flashcards

Flashcards in Bone formation Deck (18):
1

What are the two mechanisms of bone formation?

1. Intramembranous ossification2. Endochondral ossification

2

In intramembranous ossification, where does bone form?

Directly within a membrane of highly vascular mesenchyme

3

What bones are formed by intramembranous ossification?

Flat bones - skull, face, mandible, clavicle, etc.

4

The highly vascular connective tissue surrounding bone spicules and trabeculae differentiates into ____________

Bone marrow

5

What bones are formed by endochondral ossification?

Long bones - limbs, vertebrae

6

Where is the primary ossification center located?

Diaphysis

7

What makes up the periosteal bud?

Blood vessels, osteoprogenitor cells, HSCs

8

Where is the secondary ossification center located?

Epiphysis

9

How does long bone growth occur in length?

Endochondral bone formation in epiphyseal plates

10

What are characteristics of the Zone of Reserve Cartilage?

1. Typically hyaline cartilage2. Mitotically active

11

What are characteristics of the Zone of Proliferation?

1. Intense mitosis2. New organic matrix (interstitial cartilage growth)

12

What are characteristics of the Zone of Hypertrophy?

1. Chondrocytes accumulate glycogen and become vacuolated2. Cells and lacunae enlarge at expense of matrix

13

What are characteristics of the Zone of Calcified Cartilage?

1. Lacunae coalesce2. Calcification of cartilage matrix3. Chondrocytes die

14

What are characteristics of the Zone of Resorption and Ossification?

1. Calcified cartilage remnants form long spicules in direction of diaphysis2. Blood vessels bringing osteoprogenitor cells invade3. Osteoprogenitor cells emigrate to calciied cartilage matrix area, differentiate into osteoblasts

15

What color does calcified cartilage remnants stain?

Blue (hematoxylin)

16

What color does newly formed bone stain?

Pink (eosin)

17

How does bone grow in width?

Appositional growth

18

What are three mechanisms of bone repair?

1. Intramembranous bone formation2. Cartilage formation3. Endochondral bone formation