Radiobiology Exam 2 Flashcards
What are the two types of radiation units?
Traditional and system international
____is the measure of the ionization of air produced by x-radiation and gamma radiation below 3 million electron volts.
Roentgen
What is the exposure in air in the SI unit
Coulombs per kilogram
____ is the SI unit of electric charge.
Coloumb
____ is the SI unit of electrical current
Ampere
It represents the quantity of electrical charges flowing past a point in a circuit in 1 second, when an electrical current of 1 ampere is used.
Coloumb/ampere
Absorbed dose is the amount of energy absorbed by the irradiated object per unit mass and is expressed in the traditional system and SI as
Traditional RAD
SI Gray
__ is defined as an energy transfer of 100 ergs per gram of an absorbing materia
Rad
___ is defined as the energy transfer of 1 joule per Kg of the irradiated material.
Gray
Rad to Gray conversion:
Divide RAD by 100
Gray to Rad conversion:
Multiply by 100
____ is the transfer of radiation energy to atoms of air
Air Kerma
___is defined as the quantity of any ionizing radiation that has the same biologic effectiveness of one rad of x-rays
REM
How do you calculate dose equivalent
absorbed dose X quality factor
__ is a modifying factor used in the calculation of the dose equivalent to determine the ability of a dose of any kind of radiation to cause biologic damage.
quality factor
___ is the product of the average absorbed dose in a tissue or organ in the human body and its associated radiation weighting factor
equivalent dose
___is the sum of the weighted equivalent doses for all irradiated tissues or organs
effective dose
____dose is used to describe radiation exposure of a population or group from low doses of different sources of ionizing radiation.
Collective equivalent
What is the unit for collective equivalent?
person- sievert
___ is the rate at which energy is deposited in the form of a charged particle or ion pairs as it travels through matter.
LET
Alpha particles and beta particles have a __ LET and __ SI
High and high
X-radiation and gamma radiation have a __ LET and __ SI
low, low
The SI for x-radiation and gamma radiation is
1
Alpha radiation has an SI of ___and a QF of ___
2500, 20
What is the traditional unit for radioactivity? SI unit?
curie, becquerel
The __ is defined as 3.7 x 10 to the power 10 disintegration per second of any radioactive substance
curie
___ is defined as one decay per second of any radioactive substance
becquerel
___ is the time taken by a radioactive material to decay to 50% of its original activity.
half life
Milli
10 to the power -3
Micro
10 to the power -6
Nano
10 to the power -9
Diagnostic x-ray beams always result in ___exposure, which is less harmful than whole body exposure.
partial
The sequence of events that follow high level radiation exposure leading to death within days or weeks is called
acute radiation syndrome
What are the three lethal syndromes of acute radiation?
hematologic death, gastrointestinal, and central nervous
What are the 2 period associated with the three lethal syndromes?
prodromal and latent period
This immediate response of radiation sickness is the
prodromal
The severity of the symptoms is dose related: at doses in excess of ____
10 gray/1000 rad
The ___ period is the time after exposure during which there is no sign of radiation sickness
latent
The minimum dose lethal to humans is _____ Gy to the whole body.
a. 0.5
b. 1
c. 2
d. 4
c. 2
Some radiation victims of _____ syndrome(s) may recover completely.
a. central nervous system
b. gastrointestinal
c. hematologic
d. all of the above
c. hematologic
The central nervous system syndrome occurs following a whole body dose of _____ Gy or more.
a. 50
b. 20
c. 10
d. 5
a. 50
Immediately following a whole body dose of 10 Gy the victim would experience (a) _____.
a. sudden death
b. latent period
c. prodromal symptoms
d. hair loss
c. prodromal symptoms
A dose of _____ Gy or more to a small area of the body can cause skin erythema.
a. 0.25
b. 0.5
c. 1
d. 2
d. 2
There is usually a _____ before the symptoms of acute radiation syndromes appear.
a. latent period
b. recovery period
c. prolonged illness
d. loss of hair
a. latent period
The destruction of _____ cells in the intestinal lining causes death from GI syndrome.
a. muscle
b. stem
c. mature
d. blood
b. stem
A person subjected to 50 Gy to the whole body may survive for _____ before death occurs.
a. 3 hours
b. 24 hours
c. 3 days
d. 2 weeks
c. 3 days
During the latent period, the radiation victim experiences _____.
a. hair loss
b. nausea and vomiting
c. skin erythema
d. well-being
d. well-being
A local dose of _____ rad(s) or more can cause gonadal dysfunction.
a. 1
b. 5
c. 10
d. 100
c. 10
What would be the most likely immediate response to a whole body dose of 2 Gy?
a. a sense of well-being
b. diarrhea, nausea, and vomiting
c. convulsive seizures and edema
d. increased strength
b. diarrhea, nausea, and vomiting
A subject would not experience _____ following a dose high enough to cause CNS syndrome.
a. hematologic syndrome
b. gastrointestinal syndrome
c. prodromal syndrome
d. both A and B
a. hematologic syndrome
What is another name for hematologic syndrome?
bone marrow
The period of ___ is characterized by possible vomiting, mild diarrhea, malaise, lethargy, and fever.
manifest illness
The LD50/60 is the dose of radiation to the whole-body that will result in death within _____ to _____% of the irradiated population.
a. 50 days, 60
b. 60 days, 50
c. 60 minutes, 50
d. 50 minutes, 60
b. 60 days, 50
Death from acute radiation exposure follows a _____ dose-response relationship.
a. nonlinear, threshold
b. linear, threshold
c. linear, nonthreshold
d. nonlinear, nonthreshold
a. nonlinear, threshold
The LD50/60 for humans is approximately _____ Gy.
a. 1
b. 2.5
c. 3.5
d. 10
c. 3.5
High doses of radiation to a localized area can lead to _____ of tissues and organs in that area.
a. reduction in size
b. shrinkage
c. total loss of function
d. all of the above
d. all of the above
About half of the population will experience skin erythema following a localized dose of _____ Gy.
a. 5
b. 3.5
c. 1
d. 0.5
a. 5
Skin effects from localized doses of radiation follow a _____ dose-response relationship.
a. linear, threshold
b. nonlinear, nonthreshold
c. nonlinear, threshold
d. linear, nonthreshold
c. nonlinear, threshold
Localized doses of 7 Gy to the skin can cause _____.
a. death
b. permanent hair loss
c. gastrointestinal syndrome
d. all of the above
b. permanent hair loss
Ovaries are most radiosensitive during _____.
a. fetal growth
b. early childhood
c. early adulthood
d. both A and B
d. both A and B
Gonadal responses to radiation have been observed at doses as low as _____ Gy.
a. 1
b. 0.5
c. 0.2
d. 0.1
d. 0.1
The stem cells of the ovaries multiply during \_\_\_\_\_. . fetal growtha b. early childhood c. puberty d. both A and B
fetal growth
What is the ultimate cause in death in CNS syndrome?
elevate fluid content
Acute radiation lethality follows a ____, __ threshold dose response relationship.
nonlinear, threshold
A single chromosome aberration represents _____ to the DNA within the chromosome.
a. a single hit
b. severe damage
c. little damage
d. no damage
b. severe damage
The most radiosensitive cells in the hematopoietic system of the human body are the _____.
a. granulocytes
b. erythrocytes
c. lymphocytes
d. platelets
c. lymphocytes
Damage to ___ cells results in the earliest manifestation of radiation injury of the skin.
basal
Hematopoietic syndrome occurs when there is:
2 - 10 Gy (200 – 1000 rads)
Gastrointestinal syndrome occurs under
10 – 50 Gy (1000 – 5000rads)
Cerebrovascular syndrome occurs upon
50 Gy(5000 rad)
as the whole-body radiation dose increases, the average time between exposure and death decreases. This time of survival is termed the
mean survival time
What is the resultant of 200-300 kvp orthovoltage x-rays?
erythema
A single dose of ___ cause erythema
3-10 Gy
Radiation effects on skin follows a ___ threshold dose response curve.
non linear
___rad can lead to reduction in the number of spermatozoa
10
___rad results in temporary sterility for males
200-250
___rad produce permanent sterility for males
500-600
___rad suppress and delay menstruation
10
__rad causes temporary sterility.
200
___rad causes permanent sterility for females
500-625
The most radiosensitive cell during female germ cell development is the __ in the mature follicle
oocyte
Radiation induced chromosome aberrations follow a ___dose response relationship
non threshold
___ occurs on the posterior pole of the lens.
And follows a ___ threshold dose response relationship.
Cataract, nonlinear threshold dose response
Threshold dose = 200 rad
What unit of measure is used to express ionizing radiation dose to biologic material? A. Roentgen B. rad C. Rem D. Rbe
C. Rem
The ____ dose is that dose of radiation that produces twice the frequency of genetic mutations as would have been observed without the radiation.
doubling dose
Radiation protection guidelines are based on _____.
a. stochastic effects of radiation
b. deterministic effects of radiation
c. lethal effects of radiation
d. both A and B
a. stochastic effects of radiation
____ is a stochastic effect of radiation exposure.
a. Erythema
b. Epilation
c. Cancer
d. Nausea
c. Cancer
A _____ effect increases in incidence but not severity as the dose increases.
a. non-stochastic
b. stochastic
c. deterministic
d. localized
b. stochastic
Low doses of radiation have been shown to cause _____.
a. chromosome damage
b. loss of fertility
c. cataracts
d. radiodermatitis
a. chromosome damage
Chronic low doses of radiation have _____ effect on fertility.
a. no
b. an increasing
c. a strong
d. a weak
a. no
Studies of A-bomb survivors indicate that leukemia has a _____ dose-response relationship to radiation.
a. nonlinear, threshold
b. linear, threshold
c. linear, nonthreshold
d. nonlinear, nonthreshold
c. linear, nonthreshold
Radiation-induced leukemia has a latent period of _____ years.
a. 1-2
b. 4-7
c. 5-10
d. 15-20
b. 4-7
Ankylosing spondylitis patients treated with radiation showed an increased incidence of _____.
a. leukemia
b. cancer
c. early death
d. infertility
a. leukemia
It is difficult to link cancer to radiation exposure because it occurs _____ in the population.
a. with severity
b. very rarely
c. in high proportion
d. only in the elderly
c. in high proportion
Relative risk is _____.
a. expected cases/observed cases
b. observed cases/expected cases
c. observed cases – expected cases
d. expected cases – observed cases
b. observed cases/expected cases
Radiation induced skin cancer in radiotherapy patients has occurred with _____.
a. a threshold dose-response
b. a nonthreshold dose-response
c. 100% of the patients treated
d. 50% of the patients treated
a. a threshold dose-response
The theory of radiation hormesis suggests that radiation doses below 0.1 mGy are _____.
a. carcinogenic
b. beneficial
c. lethal
d. harmful
b. beneficial
A study of an irradiated population which showed a relative risk factor below 1.0 would indicate that the population had a _____ risk.
a. slight
b. no
c. reduced
d. very high
c. reduced
The most radiosensitive period during pregnancy for radiation induced congenital abnormalities is during the _____.
a. first 2 weeks
b. first trimester
c. second trimester
d. third trimester
b. first trimester
Data showing radiation-induced human genetic abnormalities _____.
a. does not exist
b. indicates responses to low doses
c. indicates responses to high doses
d. is being studied by the BEIR
a. does not exist
The threshold dose for cataract formation is known to be _____ mSv of acute exposure to the eyes.
a. 2
b. 4
c. 10
d. 20
a. 2
What is the dose equivalent limit a radiation worker may receive to his/her whole body in one year?
a. 1 rem
b. 5 rem
c. 10 rem
d. 25 rem
b. 5 rem
