Exam 4 Flashcards
A biologic reaction is produced by 4 Gyt of a test radiation. It takes 16 Gyt of 250-kVp x-rays to produce the same biologic reaction. What is the relative biologic effectiveness (RBE) of the test radiation?
RBE = Dose of standard radiation(16 Gy) / Dose of test radiation (4 Gy)
4
Which of the following is/are considered low-LET radiation(s)?
- X-rays
- Alpha particles
- Gamma rays
1 and 3 only
Because the genetic information to be passed on to future generations is contained in the strict sequence of nitrogenous bases, the loss or change of a base in the DNA chain represents a (an)
- covalent cross-link
- aneuploidy
- bleb
- mutation
mutation
Because the master molecule is unique in any given cell, no similar molecules in the cell are available to replace it; if a critical location on the master molecule is a target receiving multiple hits from ionizing radiation, the master molecule may be inactivated. If this occurs, what is the consequence for the affected cell?
- Loss of all intracellular fluid
- Increased pressure on the cell membrane leading to immediate rupture
- Disruption of cell chemistry only
- Normal cell function will cease, and the cell will die
Normal cell function will cease, and the cell will die
Which of the following curves illustrates the radiation sensitivity of a particular type of cell?
- Dose–response curve
- Cell extrapolation curve
- Cell survival curve
- Cell specialization curve
Cell survival curve
Which of the following groups of cells is the least radiosensitive?
- Nerve cells in an embryo-fetus
- Lymphocytes
- Adult nerve cells
- Immature spermatogonia
Adult nerve cells
A periodic blood count is not recommended as a method for monitoring occupational radiation exposure because
- biologic damage from ionizing radiation cannot be determined from a blood test.
- biologic damage has already been sustained when an irregularity is seen in the blood count.
- a traditional blood count is a relatively insensitive test that is unable to indicate exposures of less than 10 cGy.
2 and 3 only
Based on current data, which of the following would be considered a safe radiation dose for the gonads of both males and females?
- 0 Gy tissue
- 3 Gy tissue
- 1 Gy tissue
- 5 Gy tissue
0 Gy tissue
When LET increases, the chance of producing a significant biologic response in the radiosensitive DNA macromolecule
- grows
- remains constant, not increasing or decreasing
- decreases considerably
- decreases slightly
grows
Direct action may occur after exposure to any type of radiation, but it is much more likely to happen after exposure to
- high-LET radiation such as alpha particles
- low-LET radiation such as x-rays
- non-ionizing radiation such as microwaves
- low-LET radiation such as gamma rays
high-LET radiation such as alpha particles
If a person receives radiation exposure sufficient to cause the gastrointestinal syndrome, fatality occurs primarily because of
- catastrophic damage to the epithelial cells that line the gastrointestinal track, resulting in the death of the exposed person within 3 to 5 days from a combination of infection, fluid loss, and electrolytic imbalance
- edema in the cranial vault
- meningitis
- convulsive seizures
catastrophic damage to the epithelial cells that line the gastrointestinal track, resulting in the death of the exposed person within 3 to 5 days from a combination of infection, fluid loss, and electrolytic imbalance
Which of the following is not a form of acute radiation syndrome?
- gastrointestinal syndrome
- carcinogenic syndrome
- cerebrovascular syndrome
- hematopoietic syndrome
carcinogenic syndrome
The term LD 50/30 signifies the whole-body dose of radiation that can be lethal to
- 50% of the exposed population in 50 days
- 50% of the exposed population in 30 days
- 30% of the exposed population in 30 days
- 30% of the exposed population in 50 days
50% of the exposed population in 30 days
Which of the following are classified as early tissue reactions of ionizing radiation?
- Male and female sterility, embryologic defects, and cancer
- Blood disorders, fever, and genetic effects
- Erythema, cataract formation, and cancer
- Nausea, epilation, and intestinal disorders
Nausea, epilation, and intestinal disorders
Research has shown that repeated radiation injuries have a
- sigmoidal effect
- cumulative effect
- no discernible effect
- threshold effect
cumulative effect
The hematopoietic form of acute radiation syndrome is also called the
- bone marrow syndrome
- Auger syndrome
- cerebrovascular syndrome
- cytogenetic syndrome
bone marrow syndrome
A term that is synonymous with epilation is
- atrophy
- desquamation
- radiodermatitis
- alopecia
alopecia
During cardiovascular or other therapeutic interventional procedures that use high-level fluoroscopy for extended periods, the effects of ionizing radiation on the skin are
- nonexistent
- minimal
- significant
- moderate
significant
Early tissue reactions are
- a result of irradiation of acellular tissue
- a result of grenz rays in a diagnostic x-ray beam
- common in diagnostic imaging
- not common in diagnostic imaging
not common in diagnostic imaging
During the major response stages of acute radiation syndrome after the prodromal stage, the period when symptoms that affect the hematopoietic, gastrointestinal, and cerebrovascular systems become visible, is called
- the cytogenic syndrome
- recovery
- the latent period
- manifest illness
manifest illness
