Basic Science Flashcards
Changes associated with aging cartilage
Less chondrocytes, large chondrocytes less water less proteoglycan less chondroitin sulphate more keratin sulphate increased elasticity
Changes associated with OA in cartilage
Increased water increased collagen, becomes disorganzied increased proteoglycan turnover, decreased amount decreased elasticity increased lytic enzymes
Types of lubrication: elastohydrodynamic
deformation of cartilage with thin lining
principle mode of lubrication
types of lubrication: Boundry
nondeformable surface with only partial separation
types of lubrication: Boosted
lubrication pools
higher coefficient of friction
hydrodynamic lubrication
fluid separation
Weeping
fluids shifts toward load baring surfaces
Collagen 1
bone skin tendon anulus meniscus
Collagen 2
articular cartilage
nucleus pulposus
Collagen 3
Skin
Blood vessels
Collagen 4
Basement memebrane
What is titanium biologically inert
forms a stable oxide coating
Protein responsible for chemo resistance
P-gylcoprotein
Bacterostastic agent used in ortho
clindamycin
How to determine the number of aneuploid cell in a malignant tumor
flow cytometry
Number one contributor to backside volumetric wear
motion
Function of carbonic anhydrase
resorb bone at the ruffled border
structure of proteoglycans
multiple glycosaminoglycans bound to core protein, bound to hyaluronate via link protein
Greatest proportion of mechanoreceptors in the meniscus
posterior horn
Affect of scurvey on bone
decreased chondroitin sulphate loss of type I collagen deficient metaphysis wide growth plate junction (white line of frankyl) weak metaphyseal bone with spurs ringed epiphysies
anisotropic material
different strain when loading different directions
cephalosporin action
inhibit cell wall synthesis
Quinolone action
inhibit DNA gyrase
cipro
Aminoglycan action
inhibit protein synthesis
Rifampin action
inhibits RNA synthesis
viscoelastic material
different rates of loading
strength of early physis growth
node of ranvier
greatest tensile strength applied with bending force
periosteal membrane
Function of nitrogen containing bisphosphonates
bind to HA to prevent protein prenylation
aldendronate, risendronate
Function of non-nitrogen containing bisphophonates
replace the terminal phosphate of ATP leading to apoptosis of the osteoclast
Most important hormone for peak bone mass
estrogen
Elastic properties of ligaments
toe region - high deformation, low force
Linear region - slippage of the collagen can occur
Failure region
PTH signalling molecule
adenylate cyclase
apportionment
degree of disability that several injuries will cause
Which layer of the hypertrophic zone is most suseptible to injury
zone of provisional calcification
most common reason for liability
OA
which chemical is used to activate PRP prior to centrifugation
calcium chloride
yeild strength
when a substance undergoes plastic deformation
sclerotome of the somites forms
axial skeleton
SOX-9 is the master switch of what lineage
chondrocytes
Rituximab targets which interluekin
CD20
which molecule released during surgery promotes DVT
thromboplastin
RF targets
IgG
virchows triad
endothelial injury
venous stasis
hypercoagulability
what gives cartilage it’s strength
high water content
incompressability of water
structural organization of proteoglycan and water
proteoglycan with hydrophilic behaviour
aggrecan
superficial cartilage
parallel collagen
sparse proteoglycans
cartliage cell precursors
intermediate cartilage
random collagen
abundant proteoglycans
deep cartilage
perpedicular collagen
most amount of proteoglycans
initiator of PMMA
Benzoyl peroxide
Bisophosphonate reduction of vertebral fracture
60% in one year
40% in the next 3 years
cbaf1/runx2
osteoblast differentiation
component of bone most responsible for compressive strength
proteoglycans
component of bone most responsible for tensile strength
collagen
Ca and Vit D recommendations
Age 1-3yrs - 500mg/d Age 4-8yrs - 800mg/d Age 9-18yrs - 1000 to 1500mg/d Age >50 yrs- 1200 to 1500 mg/d calcium 800-1,000 IUs Vit. D
finite element analysis
breaking up a complex geometric form to understand it better
mechanisms of anticoagulants
warfarin - vit K, needed for gamma-carboxylation Heparin - antithrombin Fondaparineu - indirect Xa rivaroxiban - direct Xa dabigatron - direct thrombin
Function of transexamic acid
inhibit bleeding
activates plasminogen with competative binding to lysine site
effect size
magnitude of difference between control and experiement group
t2, 13
rhabomyosarcoma
X, 18
synovial sarcoma
11, 22
ewings
12, 16
mxyoid liposarcoma
9, 22
chondrosarcoma
epigenetics
changes in heritable characteristics that do not invovle DNA mutation
transgenes
artifically introduced
how do osteocytes communicate
canniculi