Sayner Intramembranous vs Endochondral Bone Formation Flashcards
1
Q
made of specialized CT (cells and ECM)
A
bone
2
Q
what matrix is calcified
A
bone
3
Q
where do RBC’s develop in the bone
A
bone marrow (in diaphysis)
4
Q
what two ions does bone act as a reservoir for
A
calcium and phosphate
5
Q
what do you do to increase serum calcium
A
break down bone
6
Q
looks like honeycomb; inside bone
A
trabeculae
7
Q
part of bone that has Haversian systems (osteons)
A
cortical bone
8
Q
surrounded by lamellae
A
osteon
9
Q
sheets of collagen
A
lamellae
10
Q
pink in H + E stain
A
collagen
11
Q
composed of protein fibers (collagen) and it’s mineralized
A
extracellular matrix of bone
12
Q
specialized cells that come from mesenchymal lineage
A
osteoprogenitor
13
Q
mesenchymal stem cells exposed to bone morphogenic proteins (BMPs) differentiate into what cells
A
osteoprogenitor cells
14
Q
reside on surface of bone tissue and undergo mitotic division and can differentiate into osteoblasts
A
osteoprogenitor cells
15
Q
cells that secrete matrix and calcify matrix
A
osteoblasts
16
Q
bone matrix that is secreted from osteoblast but NOT calcified
A
osteoid
17
Q
osteoblasts only secrete matrix where
A
on existing bone tissue
18
Q
growth from the outside that allows for thickness of bone to increase (deals with bone only)
A
appositional growth
19
Q
happens when cells within matrix secrete more layers (not for bone)
A
interstitial growth
20
Q
osteoblasts that no longer secrete matrix
A
bone lining cells
21
Q
2 main types of bone lining cells
A
periosteal and endosteal
22
Q
cells that lie on surface of bone
A
periosteal cells
23
Q
cells that line internal surfaces of bone tissue
A
endosteal cells
24
Q
osteoblast that is surrounded by matrix
A
osteocyte
25
what protein do osteoblasts secret when they secrete matrix
alkaline phosphatase (AlkP)
26
an increase in serum what can sometimes mean osteoblast activity
alkaline phosphatase
27
in bone, these occupy lacunae
osteocytes
28
in cartilage, these occupy lacunae
chondrocytes
29
one osteocyte can communicate with other osteocytes through what
cytoplasmic projections and gap junctions
30
how do nutrients get to bone tissue (b/c it is calcified, makes it harder)
fluid around osteocytes
31
blood vessels occupy this
osteon
32
nutrients travel from ______ through tissue then through _______ and ________
osteon, canaculi and lacunae
33
arrows are pointing to
lacuna and canaculi
34
arrows pointing to
osteocyte in the middle
osteoblast on outside
35
this lineage deals with bone deposition
mesenchymal lineage
36
this lineage deals with bone resorption and remodeling
hematopoetic lineage
37
remove bone tissue and are important for bone remodeling
osteoclasts
38
these cells are large and multi-nucleated and derived from hematopoietic stem cell
osteoclasts
39
these will express RANK and RANKL; will resorb bone when active
mature osteoclasts
40
expressed by osteoclast precursors
RANK
41
expressed by stromal cells
RANKL
42
soluble form of RANKL can be activated when released by activated ______ due to inflammation
T lymphocytes
43
can lead to bone resorption
inflammation
44
_____ binds to RANKL and blocks osteoclast differentiation and activity
OPG
45
mutation in OPG (osteoprotegrin) can lead to this disease
Juvenile's Paget disease
46
this disease causes increase in osteoclast activity and bone turnover; weak bones and bone; hearing loss, retinopathy, and joint pain
Juvenile's Paget disease
47
patient with this disease has woven bone rather than mature bone
Juvenile's Paget Disease
48
osteoclasts secrete acid to release ____ and _____ from calcified bone tissue (osteolysis)
calcium and phosphate
49
process that involves ruffled border, acidification of matrix, digestive enzymes that end up forming Howship's lacuna
bone resorption
50
mutation in CLCN7 gene that encodes either chloride channel or ATP proton pump; defect in bone resorption
osteopetrosis
51
features include dense bones (affects bone marrow function) with frequent fractures, growth retardation and recurrent illnesses
osteopetrosis
52
patients with this suffer from anemia and recurrent infections due to abnormal bone marrow function
osteopetrosis
53
the 2 main channels in the ruffled border that is used during bone resorption
chloride channel and ATP dependent proton pump
54
acts on osteoblasts to regulate osteoclast activity by increasing expression of RANKL and decreasing OPG
PTH (parathyroid hormone)
55
if serum calcium levels are low, what can be released
PTH to increase serum Ca2+ by bone resorption
56
how PTH is used as therapy for osteoporosis?
intermittent PTH actually increases bone density (acts on gut to increase calcium)
57
stimulates OPG and inhibits osteoclast differentiation
estrogen
58
so if _____ levels decrease in postmenopausal women and/or in older men, what can happen
estrogen; osteoporosis
59
binds to receptor on osteoclasts and induces inactivation protecting maternal bones
Calcitonin
60
patients on ___________ for too long can lead to bone loss and dermal atrophy
glucocorticoids
61
secrete osteoid and regulate matrix mineralization
osteoblasts
62
fibrous component of ECM
collagen (type I)
63
abnormal collagen type I leading to (BITE)-affects bones, eyes, teeth, ears
osteogenesis imperfecta
64
this deals with a decrease in the amount of collagen type I, but still normal collagen produced
osteogenesis imperfecta type I
65
this leads to abnormal collagen molecules being produced
osteogenesis imperfecta type II-IV
66
vitamin C deficiency leads to this; Pro and Lys unable to hydroxylate alpha chain and crosslink
Scurvy
67
ecchymosis, bleeding gums, and weak joints features of
Scurvy
68
this part of ECM contains bone matrix proteins (proteoglycan macromolecules and multiadhesive glycoproteins)
ground substance
69
when both _____ and _____ increase, crystals form
calcium and phosphate
70
increase in hydroxyapatite crystals that co-allesce eventually form
mineralized matrix
71
facilitates calcium absorption in the gut
vitamin D
72
disease that deals with vitamin D deficiency in children
Rickets
73
disease that deals with vitamin D deficiency in adults
osteomalacia
74
bone formation
osteogenesis
75
type of bone formation dealing with direct mineralization of the matrix; facial bones; appositional growth
intramembranous ossification
76
type of bone formation dealing with replacement of hyaline cartilage; short and long bones
endochondral ossification
77
immature bone that is remodeled
mature bone
78
mesenchymal stem cells get patterning signals so facial bones know where to form; once differentiated from osteoprogenitors to osteoblasts, matrix secreted and eventually calcified form sequestered calcium from blood
intramembranous ossification
79
mutation in gene encoding patterning protein (TREACLE) for intramembranous ossification causes what (severe craniofacial defects)
Treacher Collins Syndrome
80
first 3 steps of this ossification includes:
1. hyaline cartilage model
2. boney collar forms in diaphysis
3. calcification of cartilage matrix
endochondral ossification
81
3 things that happen during the 3rd phase of endochondral ossification (calcification of cartilage matrix)
1. chondrocyte hypertrophy
2. alkaline phosphatase secretion (by osteoblasts); calcification of cartilage
3. chondrocyte apoptosis
82
PB – periosteal bone
HC – hypertrophic cartilage cells
CM – calcified matrix
C – hyaline cartilage
JC – joint cavity
83
4. formation of primary ossification center
5. endochondral ossification (mixed spicules)
last steps of endochondral ossification
84
happens after bony collar forms and cells die in the middle (forming spicules)
formation of primary ossification center
85
remnants of cartilage that osteoprogenitor cells attach to during endochondral ossification
spicules
86
PB – periosteal bone
Cav – marrow cavity, which is the primary ossification center
EB – endochondral bone
C – hyaline cartilage
JC – joint cavity
87
4 steps of endochondral ossification that happens after birth
1. secondary ossification center
2. loss of epiphyseal plate (distal)
3. loss of epiphyseal plate (proximal)
4. articular surfaces
88
how does bone grow in length
epiphyseal plates moving in opp. directions
89
when diaphysis becomes continuous w/ epiphysis
epiphyseal closure
90
important zone of epiphyseal plate formation that deals with bone growth in length
zone of proliferation
91
this zone deals with chondrocytes stacking up in rows and actively secreting hyaline cartilage
zone of proliferation
92
epiphyseal plate is made of what
hyaline cartilage
93
top to bottom:
zone of reserve chondrocytes
zone of proliferating chondrocytes
zone of hypertrophic chondrocytes
zone of calcification
zone of ossification
94
osteoprogenitor cells into osteoblasts and secrete bone matrix then forming mixed spicules happens in this zone
zone of ossification
95
chondrocyte proliferation regulated by:
GH (growth hormone)
IGF
FGFR3
96
overactivity of FGFR3 blunts chondrocyte proliferation and inhibits growth; early calcification and closure of epiphyseal plates
Achondroplasia
97
woven bone persists causing
Juvenile's Paget disease
98
(weak bone)
woven/primary bone
99
strong bone
mature/lamellar/secondary bone
100
these are found ONLY in cortical bone
haversian systems
101
has blood vessels surrounded by lamella and have adjacent canals connected by volkmann's canal
central canal/Haversion canal of osteon
102
left to right:
volkmann's canal
interstitial lamellae
osteon
103
left to right:
lacunae
canaliculi
Haversion canal
104
resorption and rebuilding of bone tissue
bone remodeling
105
2 parts of bone remodeling unit
1. cutting zone (osteoclasts)
2. closing zone (osteoblasts)
106
2 parts of cutting zone
osteoclasts and capillary loop
107
2 parts of closing zone
osteoprogenitors
osteoblasts that deposit lamella and enclose blood vessels and nerves
108
cortical bone on outside
trabecular on inside (spongy)
109
when bone resorption exceeds deposition
osteoporosis
110
diagnose this using bone density test and T-scores
osteoporosis
111
what part of bone is more susceptible to osteoporosis due to higher metabolic rate and larger surface area
trabecular bone
112
freely moving; stabilized by ligaments and tendons
synovial joint
113
inflammation and joint pain due to wear and tear
osteoarthritis
114
inflammation and joint pain due to systemic response
rheumatoid arthritis
115
formed by outer CT layer and synovium
joint capsule
116
secretes synovial fluid
inner synovial membrane
117
megakaryoctes produce what and are where
platelets and in bone marrow
118
cells that will be found right up against bone
osteoclasts
119
will have distinct red granules
mast cells
120
multiple chondrocytes in a lacunae
isogenous growth (a nest)
121
cells that look like a clockface
plasma cells
122
does not have perichondrium, so can't regenerate anything
fibrocartilage
