Bone

Question 1

(msc) stem like activity, found deep in the CT covering of the bone and on the inner surface of bone that faces the central bone marrow

Answer 1

osteoprogenitor cells

Question 2

deposit osteoid, arise from “osteoprogenitor” cells in outer periosteum CT

Answer 2

osteoblasts

Question 3

fully differentiated from osteoblast trapped with lacunae deep in the mineralized bone marrow

Answer 3

osteocytes

Question 4

(hsc) reabsorb/breakdown bone matrix
inhibited by calcitonin and bisphosphorates
digest collagen and osteoid

Answer 4

osteoclasts

Question 5

high in type I collagen
35% of dry weight
has some PGs and GPs
low diffusion

Answer 5

organic (osteoid)

Question 6

contain hydroxyapite
65% of dry weight
very low diffusion

Answer 6

inorganic (mineralized)

Question 7

covers external surface of bone
contains 2 layers (outer fibrous layer with dense irregular CT and inner layer contains osteoprogenitor cells drived from mesenchymal stem cells)

Answer 7

periosteum

Question 8

made of spiracles/trabaculae that are in contact with bone marrow
shallow lacunae, can be filled in by osteoid deposited by osteoblasts

Answer 8

spongy bone

Question 9

structural units formed by concentric layers of dense bone tissue that form a cylinder with a central Haversian canal

Answer 9

compact bone

Question 10

contains blood vessels that run the length of the ostean

Answer 10

Haversian Canals

Question 11

tunnels that run perpendicular to and connect the Haversian canals

Answer 11

Volkmann’s Canals

Question 12

forms directly in mesenchyme, condenses and generates osteoprogenitor cells which differentiate and lay down bone matrix

Answer 12

intramembranous bone formation

Question 13

forms within pre-formed cartilage
the central ossification center is the ‘diaphysis’, oute ossification centres are the ‘epiphysis’
growth plate –>cartilage gradually ossifies/becomes bone

Answer 13

endochondral bone formation