Chapters 3-4: Radiation Biology & Radiation Protection Flashcards
Radiation Injury, Radiation Protection, Radiation Safety (86 cards)
Define the term: ionizing radiation
radiation capable of producing ions
Which theory of radiation injury is the least likely to occur in dental imaging?
direct theory
What are stochastic effects of radiation?
- biologic effects of radiation that occur as a direct function of dose
- the probability of occurence increases with increasing absorbed dose; however, the severity of effects does not depend on the magnitude of absorbed dose
Define the term: free radical
an uncharged, neutral atom or molecule that exists with a dingle, unpaired electron in its outermost shell
Define the term: image receptor
a recording medium (ex: PSP plates or digital sensors)
How is the response of a cell to radiation exposure determined?
- mitotic activity
- cell differentiation
- cell metabolism
Define the term: somatic cells
all cells in the body, with the exception of reproductive cells
Which type of radiation effect is not applicable in dentistry?
short-term effects
Define the term: diagnostic image
a dental image that allows for the identifying and monitoring of diseases or injuries
Cataract formation, decreased fertility and radiation sickness are all examples of whihc type of radiation effect?
nonstochastic effects
What is the ALARA concept?
a concept of radiation protection that states all exposure to radiation must be kept to a minimum, or “as low as reasonably achievable”
Define the term: sievert (Sv)
a unit of measurement for dose equivalent
Define the term: genetic effects
effects of radiation that are not seen in the person irradiated but are passed on to future generations through genetic cells
Define the term: coulomb (C)
- a unit of electrical charge
- the quantity of electrical charge transferred by 1 ampere in 1 second
List the two types of radiation effects on human tissue.
- stochastic effects
- nonstochastic effects
What are nonstochastic effects of radiation?
effects of radiation that have a threshold and increase in severity with increasing absorbed dose
Define the term: critical organ
an organ that, if damaged, diminishes the quality of an individual’s life
What determines the length of the latent period in radiation injury?
the total dose of radiation or the rate/total time of radiation
Define the term: maximum permissible dose (MPD)
the maximum dose equivalent that a body is permitted to receive within a specific period of time
What is the greatest source of background radiation in the United States?
radon gas in the soil
Define the term: cell differentiation
the individual characteristics of a cell that determine the response of a cell to radiation exposure
Define the term: cumulative occupational dose
the accumulated occupational dose for occupationally-exposed workers
Define the term: somatic effects
radiation injuries that produce changes in somatic cells and produce poor health in the irradiated individual
What are the three quantiites of measurement in radiation?
- exposure
- dose
- dose equivalent