Test 2 Flashcards
A periodic blood count is not recommended as a method for monitoring occupational radiation exposure because:
a. biologic damage from ionizing radiation cannot be determined from a blood test.
b. biologic damage has already been sustained when an irregularity is seen in the blood count.
c. a blood count is a relatively insensitive test that is unable to indicate doses of less than 10 cGyt accurately.
d. Both B and C.
D
T/F: Early tissue reactions are not common in diagnostic imaging
True
For persons with hematopoietic syndrome, survival time shortens as:
the radiation dose increases.
If bone marrow cells have not been destroyed by exposure to ionizing radiation, they can:
repopulate after a period of recovery.
In general, which of the following can human cells do?
1. Move, grow, react, and protect themselves
2. Repair damage and regulate life processes
3. Reproduce
1, 2 and 3
Laboratory experiments with mice conclude that cataracts may be caused by doses of ionizing radiation as low as:
0.1 Gyt
Neutrophils play an essential role in:
Fighting infection
Organ and tissue response to radiation exposure depends on factors such as
1. radiosensitivity.
2. reproductive characteristics.
3. growth rate.
1, 2 and 3
Radiation-induced cataracts in humans follow a ______ dose–response relationship.
threshold, nonlinear
The steps, or rungs, of the DNA ladder-like structure consist of complementary chemicals that are:
pairs of nitrogenous bases.
In the human body mineral salts are necessary for
1. proper cell function.
2. creation of energy.
3. conduction of impulses along nerves.
1, 2 and 3
What is any chemical reaction in which atoms lose electrons called?
Oxidation
Which of the following gonadal radiation doses may cause permanent sterility in a male human?
5.0 or 6.0 Gyt
What is the mean value of the radiation doubling dose for humans, as determined from studies of the children of the atomic bomb survivors of Hiroshima and Nagasaki?
1.56 Sv
Which of the following are sources of low-level radiation exposure?
1. X-rays and radioactive materials used for diagnostic purposes
2. Employment-related exposure in medicine and industry
3. Natural background radiation
1, 2 and 3
The term linear nonthreshold relationship implies that the biologic response to ionizing radiation is:
directly proportional to the dose all the way down to levels approaching zero.
Direct action may occur after exposure to any type of radiation, but it is much more likely to occur after exposure to
high-LET radiation such as alpha particles.
Made up of a molecule of glycerin and three molecules of fatty acid
Lipids
All carbon compounds, both natural and artificial
Organic compounds
The average energy deposited per unit length of track
LET
Hypothesis that when a vital macromolecule such as DNA is directly or indirectly inactivated by exposure to radiation, the cell will die
Target theory
Female and male reproductive cells
Germ cells
Estimates that a specific number of malignancies will occur as a result of exposure to ionizing radiation.
Absolute Risk Model
Form of ARS that occurs when people receive whole body doses of ionizing radiation between 1 - 10 Gy.
Bone Marrow Syndrome
Form of ARS that appears at a threshold dose of approximately 6 Gy.
Gastrointestinal Syndrome
Genetic mutations at the molecular level
Point Mutations
Predicts that the number of excess cancers will increase as the natural incidence of cancer increases with advancing age of a population
Relative Risk Model
Y (vertical) axis on Radiation dose response curve demonstrates:
Response to radiation
X (horizontal) axis on radiation dose response curve demonstrates:
Radiation dose received
