Lab 3

Question 1

chondroblast

Answer 1

cells that secrete the major component of the cartilage

Question 2

chondrocyte

Answer 2

a cell occupying a lacuna in the extracellular matrix of the cartilage

Question 3

proteoglycan

Answer 3

a compound consisting of a protein bonded to glycosaminoglycan groups, present especially in connective tissue

Question 4

perichondrium

Answer 4

a dense layer of fibrous connective tissue that covers the surface of most cartilage in the body

Question 5

appositional growth

Answer 5

occurs at the endosteal and periosteal surfaces, increases width/diameter of growing bones

Question 6

interstitial growth

Answer 6

the process of growth that occurs through the addition of new cells within the existing tissue

Question 7

periosteum

Answer 7

a dense layer of vascular connective tissue enveloping the bones except at the surfaces of the joints

Question 8

cortical (or compact) bone

Answer 8

dense and solid and surrounds the marrow space

Question 9

trabecular (or spongy or cancellous) bone

Answer 9

composed of a honeycomb-like network of trabecular plates and rods interspersed in the bone marrow compartment

Question 10

woven bone

Answer 10

formed when there is very rapid new bone formation, as occurs in the repair of a fracture

Question 11

lamellar bone

Answer 11

alignment of the collagen fibers and mineral phase

Question 12

modeling

Answer 12

the process whereby bones are shaped or reshaped by the independent action of osteoblast and osteoclasts

Question 13

remodeling

Answer 13

consists of 3 consecutive phases: resorption, during which osteoclasts digest old bone; reversal, when mononuclear cells appear on the bone surface; and formation, when osteoblasts lay down new bone until the resorbed bone is completely replaced

Question 14

Sox9

Answer 14

a protein and a major negative regulator of cartilage vascularization, bone marrow formation and endochondral ossification

Question 15

Runx2

Answer 15

a master transcription factor of osteoblast differentiation

Question 16

osteoblast

Answer 16

cells that form new bones and grow and heal existing bones

Question 17

osteocyte

Answer 17

cells inside mature bone tissue

Question 18

osteoclast

Answer 18

cells that degrade bone to initiate normal bone remodeling and mediate bone loss in pathologic conditions by increasing their resorptive activity

Question 19

endosteum

Answer 19

a membrane lining the inner surface of the bony wall also identified as the lining of the bone marrow cavity

Question 20

osteoid

Answer 20

unmineralized bone tissue and is a key structure in the development of mature mineralized bone