EX1; Biological Effects of Ionizing Radiation Flashcards

1
Q

Who is the father of radiation protection

A

William Herbert Rollins DMD MD

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

About half of the x-ray units in the US are what

A

dental

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

About how many dental radiographs are acquired per year worldwide

A

300 million

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Dental radiographs are second to what in terms of number and cost

A

chest radiographs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the two types of biological effects of radiation

A

deterministic

stochastic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

True or False

deterministic effects does not have a dose threshold

A

False; it does

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

In deterministic effects, the severity of the response is proportional to what

A

the dose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are some examples of deterministic effects

A

oral changes after radiotherapy

radiation sickness after whole body irradiation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

True or False

Deterministic effects will not happen immediately

A

False; they will

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

True or False

There is no dose threshold for stochastic effects

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

In stochastic effects, there probability of occurrence of effects is dependent on what

A

the dose; all-or-none

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are some examples of stochastic effects

A

radiation induced cancer

radiation induced mutations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

True or False;

deterministic effects of ionizing radiation include short-term, acute injury

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What parts of the body are affected by ionizing radiation

A

biological molecules
cell structures
cell cycle
tissues and organs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are some direct effects on biological molecules

A

free radical production

radiolysis of what (majority of the body is water)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is an example of an indirect effect on biological molecules

A

free radicals with water (majority of the body is water)

17
Q

About 1/3 of biological effects are caused by what

A

direction action of the x-ray photon

18
Q

About 2/3 of biological effects are caused by what

A

indirect action

19
Q

What are some effects of ionization radiation on cell structures

A

chromosome break
vacuoliziation
mitotic changes
impaired function

20
Q

What are a cells options once it has become damaged by ionization radiation

A

recovery

cell death

21
Q

Which parts of the cell cycle will cause mitotic delay if damaged by ionization radiation

A

G1 arrest
G2 block
(allows for repair)

22
Q

Which part of the cell cycle will cause cell death if damaged by ionization radiation

A

G2 phase

M phase

23
Q

What is the order for most radiosensitive to least

A

M, G2, G1, S

24
Q

What does short term effects on tissue and organs depend on

A

depends on the sensitive of the parenchymal cells

25
What does long term effects on tissues and organs depend on
depends primarily on the extent of damage to fine vasculature
26
Cells tend to be radiosensitive if they have these three properties (Law of Bergonie and Tribondeau)
high division rate long dividing future area of unspecialized cells
27
What are the most radiosensitive and radio resistant cell types
radiosensitive; stem cells, basal membrane of mucous membranes - bone marrow, intestines, etc. radioresistant; neurons and muscle cells
28
This much radiation causes death to occur within hours from apparent neurological and cardiovascular breakdown
100Gy
29
This much radiation causes death within days and is associate with bloody diarrhea and destruction of intestinal mucosa
5-12Gy
30
This much radiation causes death within several weeks after exposure due to damage to bone marrow
2-5Gy
31
Dental radiation is measured in what units
µSv (1Gy=1Sv)
32
Currently, there is no evidence of what from x-radiation used in diagnostic radiology
genetic mutation
33
Most genetic effects from radiation have observed from what
atomic bomb survivors
34
The most important somatic effect is what
radiation-induced cancer
35
Which tissues exhibit high and low susceptibility to radiation induced cancer
``` high = colon, lung, bone marrow low = bladder, thyroid, skin, brain ```
36
What are the three key points of ICRP recommendations
no practice shall be adopted unless its introduction produces a positive net benefit all exposures shall be kept as low as reasonably achievable all dose equivalent to individuals shall not exceed the the limits recommended
37
What are the annual limits for human exposure of ionizing radiation
occupational limit = 50mSV | non-occupational limit = 1-5mSV
38
Where does the majority of background come from
radon in soil and outer space