Bone pt 1

Question 1

Inorganic matrix

Answer 1

~65% of dry wt.

hydroxyapatite crystals, Ca phosphate, other minerals

Question 2

Organic Matrix

Answer 2

~35% of dry wt.
aka Osteoid.
Primarily type I collagen

Question 3

Sulfated GAGs

Answer 3

primarily chondroitin keratin sulfates

Question 4

Nonsulfated GAG

Answer 4

Hyaluronic acid.

small amounts so there are small amounts of water.

Question 5

Glycoproteins

Answer 5

binding proteins. minerals to collagen

Question 6

Sialoprotein

Answer 6

proteins that bind matrix components to cells

Question 7

Children have a higher percentage of organic or inorganic matrix?

Answer 7

organic. that results in more flexibility and possibly more greenstick fractures

Question 8

aka for osteoprogenitor cells

Answer 8

osteogenic cell

Question 9

Location of osteoprogenitor cells

Answer 9

endosteum and periosteum

Question 10

osteoprogenitor cells are derived from

Answer 10

mesenchyme and possibly chondrogenic

Question 11

osteoprogenitor cells function to supply

Answer 11

osteoblast

Question 12

Do osteoprogenitor cells divide

Answer 12

yes

Question 13

Location of osteoblast

Answer 13

endosteum and periosteum

Question 14

Osteoblast are derived from

Answer 14

osteoprogenitor cells

Question 15

Functions of osteoblast

Answer 15

1. produce osteoid
2. produce minerals that initiates calcification of newely produced matrix
3. respond to PTH

Question 16

Osteoblast responses to PTH

Answer 16

1. secrete OPGL which initiate creation of more osteoblasts
2. secrete osteoclast stimulating factor
3. produce enzymes to condition the bone surface for osteoclast

Question 17

do osteoblast divide

Answer 17

no

Question 18

Appearance of osteocytes

Answer 18

conforms to lacuna

Question 19

osteocytes are derived from

Answer 19

osteoblast

Question 20

functions of osteocytes

Answer 20

1. maintain and monitor the matrix
2. release factors to influence osteoblast activities
3. release factors to cause the creation of more osteoclast
4. sense mechanical stresses
5. Ca homeostasis

Question 21

do osteocytes divide

Answer 21

no

Question 22

Location of osteocytes

Answer 22

the matrix

Question 23

location of bone-lining cell

Answer 23

endosteum

Question 24

bone-lining cells are usually derived from

Answer 24

osteoblast. and possibly osteocytes

Question 25

function of bone-lining cells

Answer 25

usually a resting osteoblast

Question 26

can bone-lining cells divide

Answer 26

no

Question 27

location of osteoclasts

Answer 27

endosteum and periosteum

Question 28

osteoclast are derived from

Answer 28

granulocyte- macrophage progenitor cell with OPGL in bone

Question 29

osteoclast are related to

Answer 29

monocytes

Question 30

function of osteoclast

Answer 30

to resorb bone

Question 31

Mechanism of bone resorption occurs in

Answer 31

subosteoclastic compartment

Question 32

First, inorganics are dissolved using

Answer 32

acids

Question 33

second, organics are broken down using

Answer 33

lysomal enzymes

Question 34

PTH and osteoclast activity

Answer 34

will increase osteoclast activity by causing osteoblast to secrete osteoclast stimulating factor.

Question 35

Calcitonin and osteoclast activity

Answer 35

decreases osteoclast activity