Review for Test 2 (Bone and cartilage)

Question 1

Perichondrium contains

Answer 1

types 1 and 3 collagen and proteoglycans

Question 2

cartilage matrix consists of

Answer 2

type 2 collagen and proteoglycans

Question 3

Type 2 collagen is most abundant, also prevalent are

Answer 3

types: 6, 9, 11

Question 4

Explain aggrgan , hyaluronan and sulfates

Answer 4

aggrecan binds to hyaluronan and kertain and chondroitin sulfates bind to aggrecan

Question 5

Articular cartilage has no

Answer 5

perichondrium , but a periosteum

Question 6

Small molecules and devices to give for OA management

Answer 6

GAG, CS

Hyaluronic Acid ( long molecules that aggrcan binds to, is considered a device)

MMP inhibitors ( MMP breaks down aggrecan and proteins)

Question 7

Fibrocartilage contains

Answer 7

Type 1 collagen

Question 8

Bone matrix contains

Answer 8

Type 1 collagen

Question 9

Nutrient artery supplies the

Answer 9

diaphysis

Question 10

Metaphyseal artery supplies the

Answer 10

metaphysis

Question 11

Epiphyseal artery

Answer 11

epiphysis

Question 12

Which cells produce Macrophage colony stimulating factor

Answer 12

Osteoblasts

Question 13

M-CSF binds to what on what

Answer 13

receptor on monocytes

Question 14

Which cells express RANK-receptor

Answer 14

The differentiated macrophage

Question 15

Which cells synthesize RANK -Ligand

Answer 15

Osteoblast

Question 16

Osteoclasts final differentiation forms when

Answer 16

RANK L ( secreted by osteoblasts) binds to RANK -receptor secreted by the macrophage.

Question 17

Which cells secrete osteoprotegrin

Answer 17

osteoblasts

Question 18

Osteoprotegrin binds to what

Answer 18

RANK ligand with greater affinity than rank receptor

Question 19

Intramembranous bone formation

Answer 19

Mesenchyme condenses and density increases that forms bone blastema.

Osteoblasts lay down osteoid and keep laying down bone (appositional growth)

Osteocytes are formed

Question 20

Mesenchymal cells directly differentiate into

Answer 20

osteoblasts

Question 21

Endochondrial bone formation

Answer 21

starts out as undifferentiated mesenchymal cells , these cells proliferate and differentiate into chondrocytes rather than osteoblasts.

Perichondrium becomes vascularized and will secrete regulatory factors.

Chondrocytes than hypertrophy and mineralize the matrix and secrete factors that will cause vascularization to come into the bone.

Once the matrix has been mineralized and vascularization comes into the bone , the these hypertrophic cells die.

Then the osteoprogenitor cells come in either from the perichondrium or the cells coming in with the vascularization and lay down bone matrix and remodel the cartilage to bone. This starts in the center and is called the primary center of ossification which spreads end to end.

Question 22

Stimulates chondrocyte proliferation in the growth plate and prevents chondrocyte hypertrophy

Answer 22

IHH

Question 23

Longitudinal growth =

Answer 23

proliferation + hypertrophic differentiation +ECM

Question 24

Activating mutation in PTH/PTHrP

Answer 24

Jansen type metaphysical chondroplasia

**cartilage doesnt turn to bone. No hypertrophic differentiation.

Question 25

Inactivating mutation

Answer 25

Blomstrand lethal chondrolasia

accelerated hypertrophic differentiation.

** As soon as cartilage is formed, hypertrophy happens and ribs are constricted.

Question 26

Local Growth factors

Answer 26

FGF and PTHrP

Question 27

Repair: distraction Osteogenesis

Answer 27

Intramembranous model