Bone

Question 1

Bone is what kind of tissue? is is avascular?

Answer 1

connective tissue. vascular living tissue

Question 2

functions of bone tissue are…..

Answer 2

movement and support of body by spine

storage and release of calcium and PO4 ions (homeostatic mechanism, uses when ca lvls too low)

Question 3

blood cell formation occurs in bone marrow, what is it called

Answer 3

hematopoiesis

Question 4

what is the composition:
inorganic salts ____%
ground substance_____ %

Answer 4

65-75% (ca hydroxyapaptite)
30-35% (organic part)
-10% proteoglycans and 90% type 1

Question 5

what are the 2 types of bone

Answer 5

compact (outsides of bones)

cancellous (spongy) trabeculae

Question 6

lamellar are…

Answer 6

mature bone

Question 7

parts of bone are:
diaphysis is……
metaphysis is….
epiphysis is…..

Answer 7

main part of bone
growth plate btwn epiphysis and metaphysis (bone that is still growing)
end part

Question 8

articular cartilage on the end is _____ cartilage for cushioning ends of bone

Answer 8

hyaline

Question 9

long bone has what 2 types of bone

Answer 9

compact and spongy (trabeculae)

Question 10

the joint between bones is what kind of cartilage?

in between the cartilage is what?

Answer 10

articular hyaline cartilage

articular cavity

Question 11

the periosteium is ______ tissue. what does it contain.

Answer 11

immature tissue. it contains immature bone cells that cna repair bone or during development make the mature bone

Question 12

what is the functional/anatomical unit of bone

Answer 12

osteons-haversian systems

Question 13

what are osteons ? what do they have in the center?

Answer 13

concentric arrays of lamellae w/ osteocytes (mature cells)

in the center they have the haversian (central) canal that contains vessels, nerve, lymphatic

Question 14

long bone has what kind of CT?

Answer 14

fibrous ct

Question 15

volkmann’s canal (perforating canals) run ____ to haversian canals

Answer 15

perpendicular

Question 16

what volkmann’s canals do to the blood

Answer 16

bring blood horizontally and then run vertially to be the haversian canals

Question 17

volkmann’s cananls are central canals surrounded by _______ .
what are between them?

Answer 17

lamellae-rings of CT matrix

btwn the lamellae are lacunae for osteocytes

Question 18

what are in between the rings of lamellae

Answer 18

osteocytes in lacunae

Question 19

what is the central haversian canal for?

Answer 19

blood supply

Question 20

what are canaliculi

Answer 20

small canals off of lacuna

Question 21

what does the canaliculi do?

Answer 21

connects all lacuna and central canal which is bringning in oxygen for the osteocytes

*cancellous bone is not in this arrangement

Question 22

how many lamella rings can you have in an osteon

Answer 22

up to 8

Question 23

what are mature differentiated cells in lacunae that synthesize and secrete matrix?

Answer 23

osteocytes

Question 24

what synthesize and secrete osteoids?

-organic matrix in bone becomes mineralized by endoenzymes

Answer 24

osteoblasts

Question 25

what cell are multinucleate in the bone and function in reabsorption and bone remodling

Answer 25

osteoclasts

Question 26

what cells are in the periosteum (outer bone) and endosteum (inner bone) and divide and proliferate

Answer 26

osteoprogenitors

Question 27

which cells are trapped int heir matrix

Answer 27

osteocytes

Question 28

osteocyte in lacuna: - ____ RER - ____ protein synthesis - ______ chromatin - ______ active

Answer 28

little low condensed -not very active cells-shut down once it becomes trapped in its mineral matrix (calcified)

Question 29

the movement of molecutes from central canal to canaliculi and from one cell to another is through....

Answer 29

gap junctions

Question 30

osteoblasts: - ____ and ____ cells - contains ____ RER and golgi - on the ____ of developing bone - what shapeof cells? - lay down _____ proior to mineralization - process _____ cells by ____ junctions

Answer 30

- large and basophilic (lots of RER) cells - a lot of RER and golgi-active protein synthesis - surface - cuboid or polygonal - osteoid - interconnecting cells by gap junctions

Question 31

osteoblasts can become what if the matrix becomes mineralized? if this doesn't happen what can they revert back to?

Answer 31

osteocytes | immature progenitor cells

Question 32

for osteoblasts, the side facing the bone is very___

Answer 32

active -highly polarized cells

Question 33

osteoblasts synthsize and secrete ____ and ____ to mineralize the matrix

Answer 33

osteoids and extoenzymes

Question 34

what are depresoins for the osteoclats?

Answer 34

howship's lacunae. cells are sealed in this lacunae to ensure they are remodeling in the correct area

Question 35

what do osteoclasts use to dissolve mineral matrix with? | what do they use to dissolve organic matrix? what does this respond to?

Answer 35

organic acids | lysosomes -respond to calcitonin (inhibits resorbtion) and parathromone (stimulates resorbtion)

Question 36

waht does the sealing zone do what does it have a lot of in the zone? what are realsed to form hydrochloric acid to break down mineral matrix?

Answer 36

seals active side of cell off from other tissue. prevents acids and enzymes from breaking down tissue beyond it - has a lot of actin in the zone - hydroxide ions, chloride ions

Question 37

where is the active site located in osteoclasts

Answer 37

near edges where they are working on to break down the matrix

Question 38

why is bone broken down

Answer 38

in reponse to low serum calcium

Question 39

what is released to stimulate osteoclasts to release enzymes to break down the bone matrix to get calcium out of the matrix

Answer 39

parathormone from parathyroid

Question 40

what acts to increase surface aresa to secrete more enzymes and acid to breakdown the matrix

Answer 40

ruffled membrane

Question 41

what stimulates resorbtion ? | what is the opposite of this

Answer 41

parathromone. stimulates activity of osteoclasts and increase blood calcium in parathyroid gland - calcitonin is the opposite => decrease blood ca if the levels are too high in the thyroid gland

Question 42

what are the 2 types of bone formatoin? where do they occur? which is the main one?

Answer 42

1. endochondral (from cartilage matrix in long bones, MAIN) | 2. intermembranous (mesencyme to osteoblasts, short and irregular bones during development)

Question 43

what is the disease that is a dietary deficiency of calcium or vitamin D

Answer 43

rickets | -matrix doesnt mineralize and bone is weak

Question 44

what is the disease that resorbtion by osteoclasts is greater than deposition by osteoblasts

Answer 44

osteoporosis | -diminishes matrix (both mineral and organic)

Question 45

what is the calcificatoin of articular cartilage (hyaline)

Answer 45

arthritis | -calcification by invastion of blood vessels and mineralization of hyaline

Question 46

what is the progessive thickening of bone

Answer 46

paget's | -excessive bone formation folllwoing a break in bone

Question 47

bone formation: 1. ___ cartilage formed from mesenchyme 2. assume shape of ____ 3. still all cartilage-periochondirum goes into .... - osteogrogenitors start developing into .... 4. cartilage ___ and _____ - triggers blood vessel invation 5. ____ migrate w/ vessels into calcified cartilage, become osteoblasts, deposit osteoid. ____ removes dead chondrocytes 6. _____ ossification centers set up 7. continued ____ absored, BONE FINALLY PRODUCED FK

Answer 47

1. hyaline 2. final bone 3. periosteum - osteoblasts 4. proliferation and calcification 5. osteoprogenitors - osteoclasts 6. secondary 7. calcium

Question 48

which zone? | contains hyaline cartilage and no proliferation

Answer 48

zone of reserved cartilage

Question 49

which zone? | condrocytes in columns, divide and synthesize matrix

Answer 49

zone of proliferation

Question 50

which zone? | cell division stops, enlarge, start matrix calcificatoin

Answer 50

zone of maturation

Question 51

which zone? | large spaces, movement of osteoblasts. deposit collage type 1

Answer 51

zone of hypertrophy

Question 52

which zone? | cells die, matrix calcifies, progeneration and capillaries invade lacunae

Answer 52

zone of cartliage degeneration

Question 53

which zone? | osteoblasts form from progenitors

Answer 53

osteogenic zone