exam 3: bone Flashcards
formed as a result of attachment of the PDL fibers and passage of vessels and nerves into and out of the PDL
cribiform plate
(alveolar bone proper)
this term refers to that bone in which sharpey’s fibers(PDL) are embedded
bundle bone
immature bone in which the colagen fiber matrix is randomly oriented.
this type of bone is generally newly formed or deals with healing wounds
woven bone
3 things that make woven bone better than mature bone:
more cells per unit area
greater volume of non-collagenous protein
forms more rapidly than mature bone
trabecular bone that lies between the cortical plates and within the marrow spaces
spongiosa (aka cancellous)
supporting alveolar bone:
facial and lingual cortical plates:
lamellar bone
haversian bone
interstitial bone
bone is ____% inorganic and ___% organic
67% inorganic
33% organic
inorganic portion of bone
ca hydroxyapatite
organic portions of bone:
28% collagen and 5% oestocalcin, sialoprotein, phosphoprotein, osteonectin, BMP
cells associated with bone:
1
2
3
4
5
6
- osteoblast
- osteocytes
- bone lining cells
- chondroblasts
- chondrocytes
- mesenchymal cells
osteoblast that has been entrapped by it’s own osteoid matrix
osteocyte
radiate in all directions and allow diffusion of substances throughout bone
canaliculi
processes of the osteocytes travel within the _____ and connect to other osteocytes/osteoblasts allowing cell-to-cell communication. may have some mechanoreception properties as well
canaliculi
dense connective tissue, bound to bone by sharpey’s fibers that contains blood vessels, nerves, and three cell layers
periosteum
periosteum
-peripheral cell layer of:
-intermediate cell layer of:
-proximal cell layer of:
-peripheral cell layer of: fibroblasts
-intermediate cell layer of: undifferentiated mesenchymal cells
-proximal cell layer of: osteoblasts
lines the meduallary cavity and cancellous bone(trabeculae).
thinner than periosteum
endosteum
(collagen proteins associated with bone)
fibrillar: ubiquitous in distribution
type I
(collagen proteins associated with bone)
fibrillar: primarily a cartilage protein
type II
(collagen proteins associated with bone)
fibrillar: granulation and mesenchymal tissues
type III
(collagen proteins associated with bone)
fibrillar: stromal connective tissue and promotes celllular attachment and migration
type V
(collagen proteins associated with bone)
growth plate: facilitates conversion of cartilage to bone
type X
non collagenous proteins associated with bone matrix:
(like 11 answers)
osteonectin
osteopontin
osteocalcin
sialoprotein
phosphoprotein
glycoprotein
proteoglycan
bone specific protein
bone morphogenetic protein (BMP)
carboxyglutamic acid containing protein
the non-collagenous matrix proteins of bone are characterized by their:
highly acidic nature
high aggregation tendencies
calcium binding properties
process of osteoclast resorption and bone replacement by osteoblast activity.
mostly see in areas of alveolar bone affected by orthodontics
in-situ remodeling
bone formation within or between connective tissue membranes consisting of Type I collagen.
bone does NOT replace cartilage as does endochondral bone
intramembranous bone formation
bone formation within hyaline cartilage that involves a concomitant replacement of the cartilage framework by bone
endochondral bone formation
this type of bone formation is found in the inner SPONGY layers of bone, as well as sutures. It is an extremely rapid and disorganized method of bone deposition and allows for growth of the tissues surrounding it
intramembranous -bone formation
this is an example of intramembranous bone growth
woven bone
these cells secrete matrix vesicles that mineralize surrounding collagen fibers.
they usually become trapped themselves, becoming osteocytes.
osteoblasts
5 contents of matrix vesicles:
pyrophosphatase
alkaline phosphatase!!!!!!!!
glycoproteins
phosphoproteins
phospholipids
this bone formation is mostly seen in the vertebrae, long bones, base of skill, and head of mandible
endochondral
these cells make the general outline of the final bone shape.
these cells differentiate into cartilage cells (chondroblasts)
mesenchymal cells
mesenchymal cells differentiate into _____ cells which increase in size, secrete collagen and mineralize it with matrix vesicles
chondroblasts (cartilage cells)
during endochondral -bone formation
(bone formation-endochondral)
newly formed chondrocytes eventually die. vascular tissue from the surrounding _____ invades the cartilage, allowing chondrocytes and mesenchymal cells to enter the area.
_____ cells eat away cartilage and newly differentiated osteoblasts deposit _____ onto the cartilage. this is mineralized by osteocytes and bone is made.
the growth of these bones is dependant on the growth of the _____ and stops once the cartilage has been:
perichondrium
chondrocytes
osteoids
cartilage
removed
zones of cellular activity:
1
2
3
4
5
6
reserve or resting chondrocytes
proliferation
maturation
hypertrophy and calcification
cartilage degeneration
osteogenesis
bone metabolism is controlled systemically by:
locally by:
systemically: hormones
locally: mechanical factors, growth factors, cytokines
hormones important to bone metabolism include:
1
2
3
4
5
PTH
1,25-dihydroxyvitamin D
calcitonin
estrogen
glucocorticoids
IL-1
IL-6
BMP-2 and BMP-7
TGF
IGF-1
I and IGF-II
platelet-derived growth factor (PDGF)
fibroblast growth factor-betaFGF
cytokines and growth factors important to bone metabolism
under conditions that favor bone resorption, osteoblasts can be stimulated by cytokines and hormones to produce____ which in turn promotes differentiation of osteoclasts.
examples of stimulating cytokines include:
IL-6
IL-II
TNF (tumor necrosis factor-alpha)
prostaglandins E2 (PGE2)
parathyroid hormone PTH
1,25-dihydroxyvitamin D
osteoclastic resorption of bone involves the creation of a localized acidic pH to demineralize ______ and a variety of enzymes that degrade the organic bone matrix.
1
2
3
4
5
6
7`
hydroxyapatite
(osteoclast mediated resorption)
lactic acid
citric acid
free protons (H+)
acid phosphatase
arycl sulfatase
collagenase MMP
gelatinase MMP
CO2 + H2O -> HCO3- + H+
reaction is catalyzed by
carbonic anhyrase
architecture (shape) of the tooth-associated FACIAL AND LINGUAL cortical bone is dictate by:
1
2
3
4
facial-lingual alignment of teeth
mesial to distal contour of the CEJ
facial-lingual width of teeth
presence of enamel pearls or cervical enamel projections
architecture (shape) of the INTERPROXIMAL alveolar bone is dictated by:
1
2
3
4
5
facial to lingual contour of the CEJ
mesial or distal tilt of the tooth
root proximity
presence of enamel pearls
state of tooth eruption
an isolated “port-hole” in the cortical bone that allows exposure of the underlying root surface
fenestration
denuded area of cortical bone that extends through the marginal bone creating a “cleft-like” defect
dehiscence
area of bone formation that exceeds the average for a given anatomical area. the term is generally used in reference to the maxillary facial and lingual and mandibular facial
exostosis
an area of bone formation that exceeds the average for a given anatomical area. the term is used in reference to the mandibular lingual or midline of the palate
torus/tori
asymptomatic-causing painless expansion of bone
single lesion either multi or unilocular
(often confused with ameloblastoma or periapical granuloma or periapical cyst)
giant cell tumor
histology characterized by presence of numerous multinucleated giant cells in a stroma of ovoid and spindle shaped mesenchymal cells
giant cell tumor
malignancy of plasma cell origin that accounts for nearly 50% of all malignancies involving bone
multiple myeloma
in multiple myeloma, the abnormal plasma cells are typically
monoclonal (arise from a single cell)
patients with this suffer kidney failure due to overload of circulating light chain protein (bence jones protein!!) produced by the abnormal plasma cells
multiple myeloma
histology of this shows monotonous sheets of neoplastic, variably differentiated, plasmacytoid cells that invade and replace normal host tissue
multiple myeloma
“punched out” areas in the cranium
such areas are filled with the neoplastic plasmacytoid cells
multiple myeloma
malignancy of mesenchymal cells that have the ability to produce osteoid or immature bone
osteogenic sarcoma
radiographic findings vary from dense sclerosis to a mixed sclerotic-radiolucent lesion.
about 25% of lesions exhibit a sunburst pattern
osteogenic sarcoma
enbryonic origin of
enamel
dentin
cementum
bone
enamel- ectoderm
dentin- mesenchyme and ectosenchyme
cementum- mesenchyme and ectomesenchyme
bone- mesenchyme and ectomesenchyme
matrix forming cell
enamel
dentin
cementum
bone
ameloblast
odontoblast
cementoblast
osteoblast
mechanism of growth
enamel
dentin
cementum
bone
appositional
bone- appositional and interstitial
% mineral
enamel
dentin
cementum
bone
enamel 96%
dentin 65-70%
cementum 45-50%
bone 60-67%
blood supply
enamel
dentin
cementum
bone
all none but bone yes
innervation
enamel
dentin
cementum
bone
all none but bone yes
intercellular space
enamel
dentin
cementum
bone
enamel- none
dentin- dentinal tubules
cementum- lacunae and canaliculi
bone- lacunae and canaliculi
