chapter 8 part 2

Question 1

what can osteoclasts do?

Answer 1

decrease calcitonin

Question 2

endochondral

Answer 2

cartilage

Question 3

intramembranous oss

Answer 3

-mesenchyme becomes blasts when proginator has trans factor
-basophilic cytoplasm
-appotional growth
-matrix leads to woven bone
-starts when the mesenchyme arrives at the site of the future bone

Question 4

endochondral steps

Answer 4

-type 2 collagen will become CHONDROBLAST (NOT OSTEOBLAST)
-bone appears, no more chon produces
-perichondrium becomes periosteum which has an osteogenic layer and a bone ring
-at 12 weeks
-chon become hypertrophic and calcify and die from lack of nutrients
-primary center= 1st site of bone

Question 5

cartilage

Answer 5

basophilic

Question 6

bone

Answer 6

eosinophilic

Question 7

second center

Answer 7

epiphysis

Question 8

epiphyseal zones

Answer 8

-reserve (no matrix)
-proliferation
-hypertrophy
-calcified cartilage
-resorption

Question 9

proliferation

Answer 9

toward diaphysis

Question 10

calcified

Answer 10

chon suicides after matrix calcifies

Question 11

resorption

Answer 11

the zone closes to the diaphysis and b.v. invade it

Question 12

where do osteon develop?

Answer 12

compact bone
-process= internal remodelling

Question 13

resorption cavity

Answer 13

-clasts tunnel through the compact bone
-starts the process of making osteon

Question 14

making osteon

Answer 14

-remodelling unit (cutting cone and closing cone)
-canal = 200
-fill w osteoid/ matrix
-llamelae mineralize and a second mineralization happens later

Question 15

mineralization

Answer 15

happens in the matrix on the collagen and ground substance
-there can not be any ca or po4
-exocytosis happens (release)
-crystallization

Question 16

what does pth do?

Answer 16

increase calcium levels and bone growth

Question 17

what happens during injury?

Answer 17

neutrophils arrive, then macrophage
-granulation tissue forms (c.t.)
-thin becomes dense c.t.
-soft callus forms from c.t. and cartilage
-proginator cells become blasts and bone forms over the callus
-endochondreal oss happens
-spongy bone becomes compact bone