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19 Cards in this Set
- Front
- Back
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what is radiobiology?
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study of the sequence of events following the absorption of energy from ionizing radiation
the efforts of the organism to compensate and the damage to the organism |
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what are the 5 ways a cell could respond to ionizing radiation?
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1. may or may not interact with the cell
2. if interaction occurs, damage may or may not be produced 3. initial energy deposition occurs rapidly and is non selective 4. visible tissue changes are usually not distinguishable from those of others traumas 5. biological changes that occur do so after some time has elapsed |
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what is radiosensitivity of an organ?
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function of the most sensitive cell it contains
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what is our goal?
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to eradicate the tumor while not destroying normal tissues
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what elements are we working with?
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organic atoms
somatic and germ cells nucleus |
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what organic atoms are we working with?
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hydrogen, oxygen, carbon, nitrogen
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what type of nucleus are we referring to?
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cellular
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where does DNA transcription take place?
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nucleus of cell
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what are the 2 radiation types?
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high LET and low LET
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what particles have high LET?
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alpha particles, protons, some neutrons
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what particles have low LET?
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x rays, gamma rays, some neutrons
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damage to the cell can be either?
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direct of indirect
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explain indirect damage
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through the radiolysis of water.
formation of free radicals |
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what is a free radical?
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highly reactive with an unpaired outer shell electron
changes molecular structure of surroundings |
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what 3 things are in our goal?
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damage the DNA of a cell such that the cell will not survive future cell division
damage the DNA which leads to protein misconstruction and malfunction want the cell to enter programmed cell death (apoptosis) |
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what is relative biologic effectiveness? (RBE)
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ability of differing LET's to produce the same biologic effect
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what is the oxygen enhancement ratio? (OER)
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compares the response of a cell to radiation with and without the presence of oxygen
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what is the law of Bergonie and Tribondeau?
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ionization radiation is more effective against cells that:
are actively mitotic are undifferentiated (anaplastic) have a long mitotic future |
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what are the four R's of radiobiology?
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repopulation
repair of sub-lethal damage redistribution re-oxygenation |
