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Flashcards in Bone Deck (53)
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1
Q

Bone is what kind of tissue? is is avascular?

A

connective tissue. vascular living tissue

2
Q

functions of bone tissue are…..

A

movement and support of body by spine

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

3
Q

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

A

hematopoiesis

4
Q

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

A

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

5
Q

what are the 2 types of bone

A

compact (outsides of bones)

cancellous (spongy) trabeculae

6
Q

lamellar are…

A

mature bone

7
Q

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

A

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

8
Q

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

A

hyaline

9
Q

long bone has what 2 types of bone

A

compact and spongy (trabeculae)

10
Q

the joint between bones is what kind of cartilage?

in between the cartilage is what?

A

articular hyaline cartilage

articular cavity

11
Q

the periosteium is ______ tissue. what does it contain.

A

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

12
Q

what is the functional/anatomical unit of bone

A

osteons-haversian systems

13
Q

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

A

concentric arrays of lamellae w/ osteocytes (mature cells)

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

14
Q

long bone has what kind of CT?

A

fibrous ct

15
Q

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

A

perpendicular

16
Q

what volkmann’s canals do to the blood

A

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

17
Q

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

A

lamellae-rings of CT matrix

btwn the lamellae are lacunae for osteocytes

18
Q

what are in between the rings of lamellae

A

osteocytes in lacunae

19
Q

what is the central haversian canal for?

A

blood supply

20
Q

what are canaliculi

A

small canals off of lacuna

21
Q

what does the canaliculi do?

A

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

*cancellous bone is not in this arrangement

22
Q

how many lamella rings can you have in an osteon

A

up to 8

23
Q

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

A

osteocytes

24
Q

what synthesize and secrete osteoids?

-organic matrix in bone becomes mineralized by endoenzymes

A

osteoblasts

25
Q

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

A

osteoclasts

26
Q

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

A

osteoprogenitors

27
Q

which cells are trapped int heir matrix

A

osteocytes

28
Q

osteocyte in lacuna:

  • ____ RER
  • ____ protein synthesis
  • ______ chromatin
  • ______ active
A

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

29
Q

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

A

gap junctions

30
Q

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

A
  • 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
31
Q

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

A

osteocytes

immature progenitor cells

32
Q

for osteoblasts, the side facing the bone is very___

A

active

-highly polarized cells

33
Q

osteoblasts synthsize and secrete ____ and ____ to mineralize the matrix

A

osteoids and extoenzymes

34
Q

what are depresoins for the osteoclats?

A

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

35
Q

what do osteoclasts use to dissolve mineral matrix with?

what do they use to dissolve organic matrix? what does this respond to?

A

organic acids

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

36
Q

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?

A

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
37
Q

where is the active site located in osteoclasts

A

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

38
Q

why is bone broken down

A

in reponse to low serum calcium

39
Q

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

A

parathormone from parathyroid

40
Q

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

A

ruffled membrane

41
Q

what stimulates resorbtion ?

what is the opposite of this

A

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

42
Q

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

A
  1. endochondral (from cartilage matrix in long bones, MAIN)

2. intermembranous (mesencyme to osteoblasts, short and irregular bones during development)

43
Q

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

A

rickets

-matrix doesnt mineralize and bone is weak

44
Q

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

A

osteoporosis

-diminishes matrix (both mineral and organic)

45
Q

what is the calcificatoin of articular cartilage (hyaline)

A

arthritis

-calcification by invastion of blood vessels and mineralization of hyaline

46
Q

what is the progessive thickening of bone

A

paget’s

-excessive bone formation folllwoing a break in bone

47
Q

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
A
  1. hyaline
  2. final bone
  3. periosteum
    - osteoblasts
  4. proliferation and calcification
  5. osteoprogenitors
    - osteoclasts
  6. secondary
  7. calcium
48
Q

which zone?

contains hyaline cartilage and no proliferation

A

zone of reserved cartilage

49
Q

which zone?

condrocytes in columns, divide and synthesize matrix

A

zone of proliferation

50
Q

which zone?

cell division stops, enlarge, start matrix calcificatoin

A

zone of maturation

51
Q

which zone?

large spaces, movement of osteoblasts. deposit collage type 1

A

zone of hypertrophy

52
Q

which zone?

cells die, matrix calcifies, progeneration and capillaries invade lacunae

A

zone of cartliage degeneration

53
Q

which zone?

osteoblasts form from progenitors

A

osteogenic zone