Exam 1 Study Guide Flashcards
Mean lethal dose. An expression of radiosensitivity; graphically derived from the exponential portion of the cell survival curve
Do (D naught)
extrapolation number, one of three graphic parameters used to define the cell survival curve; determined by extrapolating the exponential portion of the cell survival curve to its intersection with the Y axis
N
T or F: The higher the LET, the lower the chance for biological interaction?
F
Dose from 250 KeV x-ray necessary to produce a given effect / Dose of test radiation to equal same biological effect (Fraction)
RBE
High LET radiation: (3)
neutrons
alpha particles
heavy ions
Factors that influence RBE: (3)
chosen biological effect
dose rate
fractionation
“Ratio of dose required to produce a given biologic response in the absence of oxygen/dose required to produce the same response in the presence of oxygen.” anoxic condition/aerobic condition (Fraction)
OER (Oxygen Enhancement Ratio)
SI and Conventional unit for Activity:
Bq
Ci
SI and Conventional unit for Absorbed Dose:
Gy
Rad
SI and Conventional unit for Dose Equivalent:
Sv
Rem
SI and Conventional unit for Exposure:
C/kg
Roentgen
unit of radiation absorbed dose
rad
unit of dose equivalent or occupational exposure
rem
unit of radioactivity (conventional unit) in which the number of disintegrations per second equals 3.74 x 10^10, used to measure the intensity of radioactivity in a sample of material
Ci
the SI measure of source strength or total radioactivity, and is defined as one disintegration per second, The becquerel is the SI derived unit of radioactivity. One becquerel is defined as the activity of a quantity of radioactive material in which one nucleus decays per second
Ci
most highly radiosensitive cells: (4)
lymphocytes, erythroblasts, intestinal crypt cells, spermatogonia
cells with intermediate radiosensitivity: (4)
endothelial cells, osteoblasts, spermatids, fibroblasts
cells with least radiosensitivity: (3)
muscle, nerve, chondrocytes
spur-like structures from the macromolecule main chain stick and attach to a neighboring macromolecule viscosity is increased by radiation- produced molecular cross linking.
cross-linkage
breakage of the backbone of the long-chain macromolecule. Not only the size of the macromolecule reduced, but its viscosity (thickness) is also reduced
main-chain scission
Disruptions of a single chemical bond within a macromolecule that occurs with low radiation dose. Causes cell to function incorrectly. Responsible for the late radiation effects which are observed at the whole-body level.
Point lesions
A chromosome “hit” produces a visible derangement of the chromosome; severe damage to DNA within the chromosome effect G1.
Single-hit chromosome aberrations
The breakage of a chromatid is called. During the S-phase of the cell cycle the deletion and the remaining chromosome are replicated.
Chromatid deletion
During G1 phase if two hits occur on one chromosome RING chromosomes are produced. When neighboring chromosomes each suffer one hit and then recombine to produce a dicentric chromosome.
Multi-hit chromosome aberration
