Bone

Question 1

inorganic component is composed of:
organic component is composed of:

Answer 1

hydrocyapatite

collagen, glycosaminoglycans, proteoglycans, water

Question 2

osteoclasts

Answer 2

bone resorption

Question 3

osteoblasts

Answer 3

form and create new bone

Question 4

osteocytes

Answer 4

trapped in ECM, regulate clast/blast activity

Question 5

cortical = ______ bone
trabecular = ________ bone

Answer 5

compact
cancellous, spongy

Question 6

cortical bone resists what?

Answer 6

compression, tension

Question 7

what is the fundamental unit of cortical bone

Answer 7

osteon

Question 8

What do you call the middle of cortical bone that has vessels and nerves

Answer 8

haversian canal

Question 9

lacunae contain

Answer 9

osteocytes

Question 10

what allows for communication between lacunae and ultimately reaches the haversian canals

Answer 10

canaliculi

Question 11

What are lamellae?

Answer 11

concentric rings that contain lacunae

Question 12

explain wolfe’s law

Answer 12

trabecular bone adapts and collagen organizes to adapt to magnitude and direction of stress

Question 13

Does trabecular/cancellous bone have haversian canals and osteons?

Answer 13

no

Question 14

What is the thin inner membrane called

Answer 14

the thin inner membrane called the endosteum

Question 15

what is the thin outer membrane called

Answer 15

periosteum

Question 16

is the periosteum present at articular surfaces

Answer 16

no

Question 17

Why is bone being highly vascular a good thing?

Answer 17

• very high healing potential
• very metabolically active

Question 18

cortical bone is stiff and brittle with a yield point ________ to ultimate strength

Answer 18

very close

Question 19

brittle means

Answer 19

little deformation before failure

Question 20

trabecular/cancellous bone is less stiff and is ductile, with a yield point ________ from ultimate strength

Answer 20

far

Question 21

ductile means

Answer 21

bone deforms greatly before failure

Question 22

___________ response means behavior of bone is dependent on rate load is applied

Answer 22

viscoelastic

Question 23

fast loads mean what? slow loads?

Answer 23

fast:
increase strength, stiffness, and less ductile
slow:
less strength, stiffness, and more ductile

Question 24

bending includes what forces? torsion?

Answer 24

bending: tension and compression
torsion: shear over entire material

Question 25

bone is anisotropic. What does that mean

Answer 25

strength is dependent on direction of load application

Question 26

bone is best suited for what forces?

Answer 26

compressive

Question 27

how does muscle force influence bone?

Answer 27

• give load to bone, stimulating remodeling
• may decrease load/change nature of force to prevent fracture

Question 28

what is the neutral axis of bone

Answer 28

location of bone with no stress (may result in less bone remodeling and weakness)

Question 29

in long bones, the further away from the neutral axis, the _______ the shear stresses and greater remodeling stimulus

Answer 29

larger

Question 30

why is mechanical loading good for bones?

Answer 30

it stimulates osteoblast activity to create new bone

Question 31

T or F: we have some bone remodeling happening at all times

Answer 31

t

Question 32

bone strain is greatest during ______ activities

Answer 32

dynamic

Question 33

without _________, osteoclast activity predominates and bone mass decreases

Answer 33

remodeling stimuli

Question 34

bone development begins with ____________ 6-7 weeks in utero

Answer 34

intramembranous ossification

Question 35

what is endochondral ossification

Answer 35

bone develops at secondary ossification centers by replacing cartilage. starts 6-8 weeks after conception and continues into adulthood