bones

Question 1

osseous tissue

Answer 1

bone, dense connective tissue

Question 2

osteoblast

Answer 2

mononucleate cell
from bone marrow to form new bone
immature bone cells
outer and inner surfaces of bone

Question 3

osteocyte

Answer 3

formation of bone and matric maintenance
act as pressure/stress receptors to regulate bone response
in lacuna

Question 4

osteoclast

Answer 4

bone-resorbing cell
multinucleated cells
dissolve bone

Question 5

inorganic composition of bone

Answer 5

enable bone to resist compression
2/3 of weight
makes bone hard and rigid

Question 6

organic composition of bone

Answer 6

1/3 of weight
contribute to tensile strength of bone
gives bone flexibility and toughness

Question 7

woven bone

Answer 7

mechanically weak
random fiber orientation
rapidly formed by osteoblasts
found in embryo and in fracture callus during healing

Question 8

lamellar bone

Answer 8

mechanically strong
replaces woven bone after fracture
forms on existing bone surfaces
parallel fiber alignment

Question 9

when osteoclasts reabsrorb bone they release …… and osteoblasts ——– it

Answer 9

minerals and osteoblasts absorb the minerals

Question 10

bone healing steps

Answer 10

fracture hematoma formation
fibrocartilaginous callus formation
bony callus formation
bone remodeling

Question 11

5 levels on bone microstructure

Answer 11

• cortical and cancellous bone
• osteons with haversian systems
• lamellae
• collagen fiber assemblies of collagen fibrils
• bone mineral crystals, collagen molecules and non-collagenous protiens

Question 12

material tissue density = papp

Answer 12

ratio of mass to volume of the actual bone tissue (excludes porosity)

Question 13

apparent density = papp

Answer 13

ratio of the mass of bone tissue to the bulk volume

Question 14

mineral crystal in bone

Answer 14

hydroxyapatite

Question 15

cortical / compact bone

Answer 15

cylindrical osteons and concentric lamellae
outer wall of bones
transversely anisotropic
asymmetric strength (compression)
aging reduces ultimate stress and strain

Question 16

spongy / trabecular

Answer 16

random arrangement of trabeculae
random structure with porosity
interior of bones
resist stress in different directions
non-uniform and isotropic material

Question 17

wolffs law

Answer 17

Bone remodels in response to the mechanical demands placed on
it; it is laid down where needed and resorbed where not needed

Question 18

as one ages a reduction in ………… bone and decrease in the ………… of ……… bone

Answer 18

cancellous bone
thickness of cortical

Question 19

cortical bone is strongest in

Answer 19

longitudinal compression

Question 20

trabecular bone when loaded then unloaded….

Answer 20

develops permanent residual strains