Osteochondrogenesis

Question 1

Bone histogenesis occurs by

Answer 1

intramembranous and endochondral bone formation (produce identical bones)

Question 2

the combination of bone formation and resorbtion is

Answer 2

bone remodeling (slower in secondary compared to primary bone)

Question 3

bone is a buffer for

Answer 3

calcium

Question 4

osteoclasts form an _ and then after 2 weeks they undergo apoptosis and osteoblasts start formation of new osteon (remodeling)

Answer 4

erosion tunnel

Question 5

when new bone is laid down on an eroded surface, a thin layer of _ is first produced

Answer 5

cementing substance (cementing or reversal line)

Question 6

process for flat bone formation (skull, clavicle, etc.)

Answer 6

intramembranous bone formation

Question 7

flat bone formation occurs in highly vascular

Answer 7

mesenchymal tissue

Question 8

mesenchymal cells condense into _, differentiate into osteoblasts, and then begin secreting _

Answer 8

primary ossification centers

osteoid collagen

Question 9

first bone formed is called

Answer 9

woven bone

Question 10

osteoblasts trapped in matrix become osteocytes with calficiation; small spicules of developing bone unite to form

Answer 10

trabeculae

Question 11

fusion of bony trabeculae produces _; blood vessels and other undifferentiated mesenchymal cells give rise to bone marrow

Answer 11

spongy bone

Question 12

areas of mesenchymal tissue that don’t ossify differentiate into

Answer 12

periosteum and endosteum

Question 13

woven bone initially formed from irregular osteoid collagen matrix will convert to _ in the outer layers; the inner layer remains as _

Answer 13

lamellar bone

spongy bone

Question 14

process of long bone formation

Answer 14

endochondral bone formation

Question 15

_ serves as a small model for the bone and as a scaffold for bone development (bone follows cartilage)

Answer 15

hyaline cartilage

Question 16

endochondral bone formation has 2 stages

Answer 16

development of primary and secondary stages of ossification

Question 17

primary center of ossificaiton develops at the _ of the cartilaginous model

Answer 17

midriff of the diaphysis

Question 18

vascularization of perichondrium at the primary site of ossification transforms _ to _; they then differentiate into osteoblasts; perichondrium is now called periosteum

Answer 18

chondrogenic cells

osteoprogenitor cells

Question 19

osteoblasts produce the _ on the surface of the cartilaginous model by _

Answer 19

subperiosteal bone collar

intramembranous bone formation

Question 20

the chondrocytes at the primary center of ossification secrete _; the cartilage matrix begins to calcify

Answer 20

collagen X

Question 21

osteoclasts create perforations in the bone collar to allow _ to enter the primitive marrow cavity in the C-model

Answer 21

periosteal buds (blood vessels, osteoprogenitor cells, and mesenchymal cells)

Question 22

primitive marrow cavity formed by lacunae becoming confluent due to

Answer 22

calcified cartilage matrix inhibiting nutrient diffusion and hypertrophied chondrocytes dying

Question 23

Bone matrix on the surface of the calcified cartilage forms a

Answer 23

calcified cartilage-calcified bone complex

Question 24

calcified cartilage stains _ while calcified bone stains _

Answer 24

basophilic

acidophilic

Question 25

_ begin to reabsorb the calcified cartilage-calcified bone complex enlarging the primitive marrow cavity

Answer 25

osteoclasts

Question 26

secondary centers of ossification develop at _

Answer 26

epiphyses

Question 27

when the epiphyses are filled with bone tissue, cartilage is found in 2 areas

Answer 27

articular surfaces and the epiphyseal plates

Question 28

3 steps of secondary centers of ossification

Answer 28

1) articular cartilage remains (does not contribute to bone formation) 2) epiphyseal plates continue to grow (add new cartilage to epiphyseal end while being replaced at diaphyseal end) 3) diaphyseal and epiphyseal bone becomes continuous (this connects the two epiphyseal marrow caviti

Question 29

5 epiphyseal plate zones

Answer 29

zone of reserve, proliferation, cell hypertrophy, calcification, and ossification (reabsorbtion)

Question 30

zone of reserve

Answer 30

inactive chondrocytes

Question 31

zone of proliferation

Answer 31

rapid mitotic divisions

Question 32

zone of cell hypertrophy

Answer 32

chondrocytes are enlarged

Question 33

zone of calcification

Answer 33

remnants of cartilage matrices become calcified and chondrocytes die

Question 34

zone of ossification (reabsorbtion)

Answer 34

bone is made upon the calcified cartilage followed by the reabsorbtion of the calcified bone calcified cartilage complex

Question 35

epiphysis enlarges by _ growth and _ replacement

Answer 35

cartilage | bone

Question 36

parathyroid hormone related protein (PTH-RP) stimulates _ chondrocytes to divide but also inhibits _ chrondrocyte hypertrophy

Answer 36

reserve zone | proliferative zone

Question 37

proliferation of _ from the periosteum and endosteum surrounding the fracture

Answer 37

osteoprogenitor cells

Question 38

a _ forms both internally and externally at a fracture site

Answer 38

callus

Question 39

during bone repair, endochondral bone formation replaces the cartilage with _ bone

Answer 39

primary (woven)

Question 40

the irregularly arranged trabeculae of primary bone joins the ends of the fractured bone forming a _

Answer 40

bony callus

Question 41

primary bone is eventually reabsorbed and replaced with

Answer 41

secondary lamellar bone

Question 42

hairline fracture heal via

Answer 42

intramembranous bone formation (occurs at the periosteal surface)

Question 43

immoveable joints composed of connective tissue, cartilage, or bone

Answer 43

synarthroses (unite the first rib to the sternum)

Question 44

joints with slight movements commonly found in IV disks

Answer 44

amphiarthroses

Question 45

permit maximum movement

Answer 45

diarthroses (also called synovial joints)

Question 46

diarthroses unite long bones. they are surrounded by a 2-layered _, encloses and seals the articular cavity, which contains _ a colorless viscous fluid rich in _ and proteins

Answer 46

capsule synovial fluid hyaluronic acid

Question 47

diathroses have a fibrous layer of dense connective tissue

Answer 47

external (fibrous) capsular layer

Question 48

diarthroses internal (synovial) capsular layer has two types of cells

Answer 48

A and B

Question 49

type A cells are

Answer 49

phagocytic with a well-developed Golgi complex and many lysosomes

Question 50

Type B cells

Answer 50

resemble fibroblasts with a well developed rER; probably secrete synovial fluid (nutrients diffuse to hyaline cartilage from synovial fluid)

Question 51

synovial tissue under the outer epithelial layers can consist primarily of

Answer 51

loose, dense irregular, or adipose tissue depending upon location

Question 52

hereditary disease with abnormal osteoclast function (no remodeling occurs)

Answer 52

osteopetrosis

Question 53

form of osteopetrosis

Answer 53

Albers-Schnoberg disease (marble bone disease)

Question 54

loss of bone mass (primary trabecular); usually has normal rate of resorbtion but decreased bone formation

Answer 54

osteoporosis

Question 55

rheumatoid arthritis starts as an inflammatory

Answer 55

reaction in synovial tissue