180quiz2typed

Card Set Information

Author:
Anonymous
ID:
172338
Filename:
180quiz2typed
Updated:
2012-09-21 02:09:52
Tags:
180quiz2typed
Folders:

Description:
180quiz2typed
Show Answers:

Home > Flashcards > Print Preview

The flashcards below were created by user Anonymous on FreezingBlue Flashcards. What would you like to do?


  1. Indirect Effect
    • previously mentioned
    • agents produce indirect effects because the damage is not caused by the
    • radiation but the indirect effect of the radiation.
  2. Effects on DNA
    •Single strand break

    • –Point mutation, commonly occur
    • with low LET

    indirect bc low LET

    •Easy type of damage to repair
  3. Target Theory
    • •Basically, the DNA molecule is the most
    • important molecule

    • •Therefore, if the DNA molecule is hit and
    • inactivated the cell will most likely die

    water 80% DNA 1%
  4. Cellular Effects of
    Irradiation
    •Instant death

    –1000 Gy in a few seconds

    • •Reproductive death at the cellular level
    • –10 Gy

    • •Apoptosis
    • –Cells die without attempting cell
    • division
  5. Cellular Effects of
    Irradiation
    •Loss of function

    • •Chromosome breakage
    • –Can lead to genetic effects
    • changes are passed down
  6. Mitotic death
    • Cell death occurs after cell
    • division
  7. Mitotic delay
    • Mitosis occurs after missing a
    • division cycle
  8. Cell sensitivity
    Immature cells

    • –Non-specialized and rapid cell
    • division

    • –Both conditions that encourage
    • radio-sensitivity
  9. Cells are radio sensitive in?
    mitosis
  10. immature cells more radiosensitivity than?
    cells
  11. Lethal Dose
    •Humans

    –300 – 400 rads, 3 – 4 grays

    • •Expressed as LD50/30
    • in most mammals or LD50/60 in humans

    • blood cell count problem;GI tract problem
    • –The first number is percentage of
    • effect (death) second number is how many days for the effect to occur
  12. Dose-Response Curves
    • •Linear or non-linear
    • •Threshold or non-threshold

    • Type of curve depends on the effect being
    • observed or reported
  13. Radiation Protection
    •Based on a linear non-threshold curve

    •Any radiation has the potential for problems

    •This is the most cautious curve.
  14. Early non-stochastic
    effects
    • •Occur within weeks of exposure
    • –Nausea
    • –Fatigue = no blood cell
    • –Erythema
    • –Epilation =hair loss
    • –Symptoms of these effects

    • •Generally, classified as Acute Radiation
    • Syndromes
  15. ARS
    •Stages

    • –Prodromal
    • Symptoms will be present

    • –Latent
    • Symptoms will resolve or be
    • dormant

    • –Manifest
    • You got problems
  16. ARS
    Acute radiation syndrome
  17. Types of ARS
    • Hematopoietic
    • 100 – 1000 rads

    • GI
    • 600 – 1000 rads

    • Cerebrovascular
    • Up to 5000 rads

    •Death in 2 to 3 days
  18. Late Non-stochastic
    Effects
    •Cataracts

    •Fibrosis

    • •Organ atrophy
    • Loss of parenchymal cells

    • •Decreased fertility
    • sterility
  19. Late Stochastic Effects
    •Cancer

    •Genetic defects
  20. Embryologic Effects
    • •Most sensitive during organogenesis
    • 10 days to 6 weeks
    • 2 weeks to 8 weeks
  21. Effective Dose Limiting
    System
    • The idea that exposure to radiation can/may
    • induce cancer.

    • The result is that radiation
    • protection guidelines are based on the possibility of getting cancer not some
    • other effect.

    minimize cancer
  22. Radiation Safety Program
    • •All facilities must have a radiation
    • protection/safety program in place.

    •Radiation Safety Committee

    –Radiation safety Officer (RSO)
  23. Effective Dose Limiting
    System
    • •Looks to establish the upper limit of
    • exposure to ionizing radiation resulting in a negligible risk of injury or
    • genetic defect.

    • •Can be whole body, partial body (extremity,
    • eye) and individual organs.

    • –Non-stochastic (deterministic)
    • and stochastic (probabilistic)

    • •Occupational limits are based on comparing
    • outcomes against other occupational hazards.
  24. Radiation Induced
    Responses - non-stochastic
    •Non-stochastic = Somatic

    –Deterministic

    –Directly related to the dose received, threshold

    •Early

    –Erythemia

    –Decreased blood count

    –Epilation

    –Acute Radiation Syndromes (ARS)

    •Late

    –Cataracts

    –Fibrosis

    –Sterility

    –Organ atrophy
  25. Radiation Induced
    Responses - Stochastic
    Stochastic = Genetic

    –Probabilistic

    • –Mutational, non-threshold,
    • randomly occurring, all or nothing

    • –The greater the dose the greater
    • the chance of the effect occurring.  NOT
    • is it going to occur.

    –Cancer and genetic effects
  26. Basis for Effective Dose
    Limiting System
    • While we have already discussed the fact
    • different forms have radiation have different effects (equivalent dose) some
    • tissues are more sensitive than others.

    • •Tissue weighting factor allows overall risk
    • to be determined.
  27. Occupational MPD
    •50 mSv or 5 rem annually

    •Pregnant

    –0.5 mSv per month

    • –5 mSv for
    • the entire pregnancy
  28. Radiation Hormesis
    • •The potential that small radiation exposure
    • is actually beneficial.
  29. Public MPD
    •1 mSv or 0.1 rem or 100 mrem year

    •Educational exposure

    • –1 mSv or
    • 0.1 rem annually

    • –Notice it is the same as the
    • general public

What would you like to do?

Home > Flashcards > Print Preview