Bone Formation

Question 1

Intramembranous ossification

Answer 1

replaces mesenchyme

Question 2

Endochondral ossification bone’s

Answer 2

preceded by cartilage model

Question 3

What type of bone is replaced before secondary bone in both intramembranous and endochondral ossification

Answer 3

Woven bone appears first

Question 4

Intramembranous bone formation is for what type of bone

Answer 4

Flat bones, pelvis, ribs, sternum, scapula

Question 5

What type of cells differentiate into osteoblasts Paraxial mesoderm

Answer 5

describe process of intrmembranous bone ossification mesenchyme cells differentiate into osteoblasts secreting osteoid at multiple ossification centers, osteoid calcifies, fusion of ossification centers

Question 6

Where do osteoblasts secrete osteoid

Answer 6

ossification centers

Question 7

what happens to the mesenchyme that do not form bone

Answer 7

these become the bone marrow and periosteum

Question 8

Compact bone surrounds_____

Answer 8

Spongy bone

Question 9

Endochondral ossification is for what types of bones

Answer 9

Most bones, long bones, vertebrae,

Question 10

Endochondral bone formation permits

Answer 10

Permits functional stress

Question 11

what type of cartilage makes the model to be replaced in endochondrlal ossification

Answer 11

hyaline type II cartilage???? not sure that this is correct

Question 12

Explain endochondrla ossification

Answer 12

Mesenchyme differentiates into cartilage surrounded by perichondrium, chondrocytes resorb cartilage which begins calcifying, chondrocytes die leaving hard matrix, Concurrently vessels are invading perichondrium. Progenitor cells differentiate into osteoblasts and perichondrium is now periosteum. Osteoblasts form periosteal bone collar. Primary ossification center forming with vessels and osteoblasts penetrating diaphysis, osteoid hardening and cartilage degenerating. Secondary ossification centers form in the epiphysis. Bone replaces cartilage via osetoblasts everywhere except articular surfaces & ends of diaphysis (epiphyseal growth plates). Bone inside diaphysis removed by osteoclasts forming medullary cavity.

Question 13

periosteum, what did it differentiate from

Answer 13

from perichondrium surrounding cartilage model

Question 14

What forms the periosteal bone collar

Answer 14

Osteoblasts

Question 15

what differentiated into osteoblasts

Answer 15

progenitor cells

Question 16

periosteal bone collar forms around forms around the ______

Answer 16

diaphysis in endochondral ossification

Question 17

Primary ossification center forming when

Answer 17

with vessels and osteoblasts penetrating diaphysis, osteoid hardening and cartilage degenerating this is formed

Question 18

where do secondary ossification centers form

Answer 18

in the epiphysis

Question 19

Bone replaces cartilage everywhere except

Answer 19

articular surfaces & ends of diaphysis

Question 20

medullary cavity is formed by

Answer 20

Bone inside diaphysis removed by osteoclasts forming this..

Question 21

Cartilage repair has rich capacity for repair T/F

Answer 21

False, poor capacity because of poor vascular supply

Question 22

In cartilage repair, why is the presence of the perichondrium important?

Answer 22

If this is present, then the precursor cells differentiate into chondroblasts producing more matrix

Question 23

Perichondrium

Answer 23

what first surrounds developing bone in beginning of endochondral bone growth before the bone collar and what eventually becomes the periosteum.

Question 24

what forms bony callus

Answer 24

osteoprogenitor cells laying new primary bone

Question 25

soft callus is a

Answer 25

fibrocartilage

Question 26

Epiphyseal growth plates composed of

Answer 26

hyaline cartilage type II

Question 27

How does longitudinal growth occur

Answer 27

epiphyseal growth plates, cartilage proliferates and replaced by bone

Question 28

What are the 5 zones of epiphyseal plate

Answer 28

Resting zone, proliferative zone, hypertrophic zone, calcified cartilage zone and ossification zone

Question 29

What zone is near the epiphyseal end? by diaphysis?

Answer 29

resting zone ossification zone

Question 30

Resting zone

Answer 30

Typical hyaline cartilage

Question 31

Proliferative zone

Answer 31

chondrocytes divide into columns

Question 32

hypertrophic zone

Answer 32

chondrocytes grow in size

Question 33

calcified cartilage zone

Answer 33

Cartilage calcifies, chondrocytes apoptosis

Question 34

Ossification zone

Answer 34

osteogenic cells & vessels invade, osteoblasts secrete osteoid over calcified cartilage and osteoclasts resorb cartilage

Question 35

during growth epiphyseal growth plate changes in thickness T/F

Answer 35

F, long bone grows in length only

Question 36

Eventually epiphyseal plate is replaced with bone T/F

Answer 36

True

Question 37

when is the epiphyseal plate eliminated

Answer 37

different time but usually 25yrs.

Question 38

Bone turnover involves

Answer 38

resorption & laying down new bone

Question 39

bone growth =

Answer 39

rate bone formation \> bone loss

Question 40

Why do bones have an excellent capacity for repair?

Answer 40

due to extensive vasculature and osteoprogenitor cells in endosteum, periosteum

Question 41

Endosteum

Answer 41

a thin vascular membrane of connective tissue that lines the surface of the bony tissue that forms the medullary cavity of long bones.

Question 42

Osteocytes lie within

Answer 42

Lacunae

Question 43

Process of fracture repairs

Answer 43

Blood clot forms, (hematoma), bones resorbed (osteoclasts), fibrocartilage-like soft callus formed, osteoprogenitor cells lay primary bone forming bony callus,

Question 44

blood clot in bone repair

Answer 44

hematome

Question 45

soft callus is formed from

Answer 45

bone resorption via osteoclasts into this