If a quantity of radiation is delivered to a body in a single dose, its effect
A
will be greater than if it were delivered in a number of doses over a long period of
time.
B
will be less than if it were delivered a number of doses over a long period of time.
C
has no relation to how it is delivered in time.
D
is solely dependent on the radiation quality.
Give this one a try later!
a
The effects of a quantity of radiation delivered to a body are dependent on
several factors: the amount of radiation received, the size of the irradiated
area, and how the radiation is delivered in time. If the radiation is delivered
in portions over a period of time, it is said to be fractionated and has a less
harmful effect than if the radiation were delivered all at once. With
, fractionation, cells have an opportunity to repair, and so some recovery
occurs between doses. (Bushong, p 496)
What is the annual dose-equivalent limit for the skin and hands of an occupationally
exposed individual?
A
30 mSv
B
150 mSv
C
500 mSv
D
650 rem
Give this one a try later!
c
The dose-equivalent limit for the hands and skin of an occupationally
exposed individual is 500 mSv. The dose-equivalent limit for the lens of the
eye is 150 mSv. An occupationally exposed individual may receive up to 30
mSv in a given calendar quarter, or 13-week period. However, that
individual may not exceed 50 mSv in that particular year. If, for example,
one received 30 mSv during the first 3 months of a year, that individual
must not receive more than 20 mSv in the remaining 9 months. (Bushong,
9th ed, p 619)
Which of the following expresses the gonadal dose that, if received by every member
of the population, would be expected to produce the same total genetic effect on
that population as the actual doses received by each of the individuals?
A
Genetically significant dose
B
Somatically significant dose
C
,Maximum permissible dose
D
Lethal dose
Give this one a try later!
a
The genetically significant dose (GSD) illustrates that large exposures to a
few people are cause for little concern when diluted by the total
population. On the other hand, we all share the burden of the radiation that
is received by the total population, and especially as the use of medical
radiation increases, each individual's share of the total exposure increases.
(Bushong, 8th ed., p. 589)
The variation in photon distribution between the anode and cathode ends of the x-ray
tube is known as
A
the line focus principle.
B
the anode heel effect.
C
the inverse square law.
D
Bohr's theory.
Give this one a try later!
b
Because the focal spot (track) of an x-ray tube is along the anode's beveled
edge, photons produced at the target are able to diverge toward the
cathode end of the tube, but are absorbed by the "heel" of the anode at
the opposite anode end of the tube. This results in a greater number of x-
ray photons distributed toward the cathode end and is known as the anode
heel effect. The line focus principle is a geometric principle illustrating that
the effective focal spot is always smaller than the actual focal spot. The
inverse square law of radiation deals with the relationship between
, distance and radiation intensity. Bohr's theory refers to an atom's
resemblance to the solar system. (Selman, p 253)
Which of the following types of adult tissues is (are) relatively insensitive to radiation
exposure?
1. Muscle tissue
2. Nerve tissue
3. Epithelial tissue
A
1 only
B
1 and 2 only
C
2 and 3 only
D
1, 2, and 3
Give this one a try later!
b
Because muscle and nerve tissues perform specific functions and do not
divide, they are relatively insensitive to radiation exposure. Epithelial cells
cover the outer surface of the body; they also line body cavities and tubes
and passageways leading to the exterior. They contain very little
intercellular substance and are devoid of blood vessels. Because epithelial
cells constantly regenerate through mitosis, they are very radiosensitive.
(Dowd and Tilson, 2nd ed., pp. 121-122)
Biologic material is least sensitive to irradiation under which of the following
conditions?
A
Anoxic
B
Hypoxic
C
A
will be greater than if it were delivered in a number of doses over a long period of
time.
B
will be less than if it were delivered a number of doses over a long period of time.
C
has no relation to how it is delivered in time.
D
is solely dependent on the radiation quality.
Give this one a try later!
a
The effects of a quantity of radiation delivered to a body are dependent on
several factors: the amount of radiation received, the size of the irradiated
area, and how the radiation is delivered in time. If the radiation is delivered
in portions over a period of time, it is said to be fractionated and has a less
harmful effect than if the radiation were delivered all at once. With
, fractionation, cells have an opportunity to repair, and so some recovery
occurs between doses. (Bushong, p 496)
What is the annual dose-equivalent limit for the skin and hands of an occupationally
exposed individual?
A
30 mSv
B
150 mSv
C
500 mSv
D
650 rem
Give this one a try later!
c
The dose-equivalent limit for the hands and skin of an occupationally
exposed individual is 500 mSv. The dose-equivalent limit for the lens of the
eye is 150 mSv. An occupationally exposed individual may receive up to 30
mSv in a given calendar quarter, or 13-week period. However, that
individual may not exceed 50 mSv in that particular year. If, for example,
one received 30 mSv during the first 3 months of a year, that individual
must not receive more than 20 mSv in the remaining 9 months. (Bushong,
9th ed, p 619)
Which of the following expresses the gonadal dose that, if received by every member
of the population, would be expected to produce the same total genetic effect on
that population as the actual doses received by each of the individuals?
A
Genetically significant dose
B
Somatically significant dose
C
,Maximum permissible dose
D
Lethal dose
Give this one a try later!
a
The genetically significant dose (GSD) illustrates that large exposures to a
few people are cause for little concern when diluted by the total
population. On the other hand, we all share the burden of the radiation that
is received by the total population, and especially as the use of medical
radiation increases, each individual's share of the total exposure increases.
(Bushong, 8th ed., p. 589)
The variation in photon distribution between the anode and cathode ends of the x-ray
tube is known as
A
the line focus principle.
B
the anode heel effect.
C
the inverse square law.
D
Bohr's theory.
Give this one a try later!
b
Because the focal spot (track) of an x-ray tube is along the anode's beveled
edge, photons produced at the target are able to diverge toward the
cathode end of the tube, but are absorbed by the "heel" of the anode at
the opposite anode end of the tube. This results in a greater number of x-
ray photons distributed toward the cathode end and is known as the anode
heel effect. The line focus principle is a geometric principle illustrating that
the effective focal spot is always smaller than the actual focal spot. The
inverse square law of radiation deals with the relationship between
, distance and radiation intensity. Bohr's theory refers to an atom's
resemblance to the solar system. (Selman, p 253)
Which of the following types of adult tissues is (are) relatively insensitive to radiation
exposure?
1. Muscle tissue
2. Nerve tissue
3. Epithelial tissue
A
1 only
B
1 and 2 only
C
2 and 3 only
D
1, 2, and 3
Give this one a try later!
b
Because muscle and nerve tissues perform specific functions and do not
divide, they are relatively insensitive to radiation exposure. Epithelial cells
cover the outer surface of the body; they also line body cavities and tubes
and passageways leading to the exterior. They contain very little
intercellular substance and are devoid of blood vessels. Because epithelial
cells constantly regenerate through mitosis, they are very radiosensitive.
(Dowd and Tilson, 2nd ed., pp. 121-122)
Biologic material is least sensitive to irradiation under which of the following
conditions?
A
Anoxic
B
Hypoxic
C
