Week 3 OR Biology 1 part 2 Flashcards
we deal with stochastic when..
taking dental xrays
we deal with deterministic dosage with this profession
oncologist.
cancer
scientists have good understanding of these effects..
because:
however, it does not occur in dental radiology because
on deterministic effefcts
cell death is easy to measure and generally occurs within a short time after exposure
because dose is below threshold
there are no super accurate studies on low dose radiation because..
radiation increases this
there isnt anything to
no mutations are radiation specfific. there is no specific kind of cancer because you had an xray
incidence of cellular mutation, but number of cellular mutations that become cancer is unknown
cancer risk %
rely on…
high background rate 40%
cant differentiate small number of cancers that may have been caused by radiation from background risk
extrapolation from data at high doses
most significant example of high dose radiology:
a bomb
hereditary stochastic effects are easily measured by
no signficant increase in genetic related diseases in…
transmission of condition to offspring
children of a bomb survivors
radiosensitivity:
susceptibility to be effected by radiation
radiosensitivity depends on:
radiation factors: dose, dose rate, LET
cell factors: cell cycle stage at the time of exposure. laws of bergonie and tribondeau
environment: o2 conc, presence of radioprotectors and radio sensitizers
diagnostic x-rays have…but…
have low dose, but are in higher dose rate. relative to background radiation
xrays have this LET(linear energy transfer)
low LET. least damaging ex:xrays.
high LET: most damaging, alpha particles
cell cycles are most sensitive in…but least sensitive in..because…
most s in mitosis
least s in Late S
because there are checkmarks and repair mechanisms at late Sphase
