Exam 1 - 5. Radiation Biology

Question 1

3

Radiographs are made with _____ radiation

Question 2

3

Follow the ______ principle to minimize risks.

Question 3

3

What does ALARA stand for?

Question 4

4

Low energy X-rays are ______ by the body (_____absorption).

Question 5

4

Low energy X-rays occur when X-rays interact with ____ tissues like ____ or _____. These low energy x-rays are _____.

Question 6

4

High energy X-rays undergo _____. This releases ________ electrons which cause ______ when interacting with _________.

Question 7

4

What is the major site of biologic damage?

Question 8

5

In direct actions, the photon directly interacts with and ionizes a _______. The ________ produced by the ionization interaction (________) may also interact directly with biologic macromolecules.

Question 9

5

What fraction of radiation is direct action?

Question 10

5

Indirect action, the secondary electron interacts with, for example, a _____ to produce a ______, which in turn produces the _______.

Question 11

5

What fraction of radiation is indirect radiation?

Question 12

6

Direct and indirect radiation both yield ________, which are ________.

Question 13

6

Free radicals are ______ reactive and have ______ half lives.

Question 14

6

Free radicals play a dominant role in producing _______ in _______.

Question 15

7

In direct action, free radical generation occurs within _____ of the passage of a photon

Question 16

7

Free radicals quickly reform into _______.

Question 17

7

What would be an example of free radical dissociation using an equation?

Question 18

7

What would be an example of free radical cross-linking using an equation?

Question 19

7

Direct actions dominate with ______) radiations and are less predominant with _____ radiations such as ______.

Question 20

8

Water constitutes approximately ___% of mammalian cells.

Question 21

8

When water is irradiated, it _____ into _____. This is referred to as _____.

Question 22

8

The initial series of interactions of x-ray photon with water produce _____ and _______ free radicals that interact with biologic macromolecules

Question 23

8

The hydroxyl radical is _____ and is estimated to cause ______ of the biologic damage to mammalian cells from x-rays.

Question 24

9

Indirect action results in _____ damage.

Question 25

10 What is the range of time for energy absorbed in radiation biology Excitation and ionization? Chemical reactions? Bioeffects?

Question 26

11 What is the term for the time between when energy is absorbed and damage done to when the signs and symptoms are visible?

Question 27

11 The latent period may take ____ or up to ____ or more.

Question 28

11 How long the latent period takes depends on the ______ and the _______.

Question 29

12 What are the two most important damages to DNA?

Question 30

13 During what phase are the cells most sensitive to radiation?

Question 31

14 During what phase of the cell cycle are cells less and LEAST sensitive to DNA damage?

Question 32

13 If a DNA strand break occurs prior to chromosomal duplication (late G1/early S), the break is ______ and both sister chromatids will ______. These are known as _______.

Question 33

13 If the DNA strand break occurs after chromosomal duplication (late S/G2), only ________ will encounter the break. These are known as ______.

Question 34

14 Stochastic effects are caused by ______.

Question 35

14 Deterministic effects are caused by ____.

Question 36

14 Is there a minimum threshold dose for stochastic effects?

Question 37

14 Is there a threshold dose for deterministic effects?

Question 38

14 Describe the severity of clinical effects and dose for stochastic effects.

Question 39

14 Describe the severity of clinical effects and dose for deterministic effects.

Question 40

14 For stoachastic effects, the frequency of the effect is proportional to ____. The higher the dose, the _____ the risk of manifesting the disease.

Question 41

14 For deterministic effects, the probability of effect is ____ of dose. Most individuals manifest the effect when the ______ is exceeded.

Question 42

14 Are stochastic effects caused by doses used in diagnostic radiology?

Question 43

14 Are deterministic effects caused by doses used in diagnostic radiology?

Question 44

14 What is an example of stochastic effects?

Question 45

14 What is an example of deterministic effects?

Question 46

16 What is the term for damage to body cell and is passed on to the same type of cell in that person, not to future offspring?

Question 47

17 What is the most likely result of stochastic effects?

Question 48

20 Is the nucleus or the cytoplasm more sensitive for determinisitic effects?

Question 49

20 ____ in the chromosome is the most sensitive site for deterministic effects.

Question 50

21 What is the term for damaged cells releasing molecules that kill adjacent cells?

Question 51

22 The Law of Bergonie and Tribodeau states that radiosensitivity of a biological tissue is directly proprtional to the ______ and inversely proportional to the _______ of its cells.

Question 52

22 Radiosensitivity is greatest for those cells that have a high _____ and a long _____, such as the ______ and _____ mucosa.

Question 53

22 Radiosensitivity is greatest for cells that are differentiated or undifferentiated?

Question 54

23 The most sensitive cells to deterministic effects are those that _____, are ____, and are ______.

Question 55

23 _____ cells are most sensitive, followed by cells of ___, ___, ____, and _____.

Question 56

24 The cells that are least sensitive to deterministic effects are _____ cells, followed by ___, ____, ____, and ____.

Question 57

26 What does this describe? -Acute radiation syndrome that causes nausea, vomitting, and diarrhea -1-2 Gy

Question 58

26 What does this describe? -Acute radiation syndrome that damages the bone marrow, causing infection, bleeding, and anemia. -2 to 7 Gy

Question 59

26 What does this describe? -Acute radiation syndrome that causes damage to libing of the GI tract, resulting in ulceration, septicemia, and death -7-15 Gy

Question 60

26 What does this describe? -Acute radiation syndrome that causes death. -greater than 50 Gy

Question 61

27 Late effect of low doses: Somatic Cataract formation has a threshold of ___ Gy and a dental dose of ____ to ____ mGy (____ times lower than the threshold).

Question 62

28 Effects of low doses: fetal -0-9 days -most sensitive stage for lethal effects

Question 63

28 What is the threshold for effect for preimplantation stage?

Question 64

28 Effects of low dose: fetal What is the stage that is 10 days to 8 weeks and causes mental retardation, microcephaly, growth retardation?

Question 65

28 Effects of low doses: fetal -8 weeks to 25 weeks -causes mental retardation

Question 66

28 Late fetal period: Excess absolute risk is about ____ Gy for early child cancer.

Question 67

29 Fractionation is spreading the dose out over ___ or giving it in ____ to ___ the damage.

Question 68

30 Smaller volume has what effect on cells damaged?

Question 69

30 What effect does lower oxygen have on radiation? Why?

Question 70

30 Higher Linear Energy Transfer (LET) = more ______

Question 71

31 Fractionation of daily small doses of radiotherapy for the oral cavity provides _____ tumor destruction than with a large single dose.

Question 72

31 What are the "4 R's" for benefits of fractionation?

Question 73

32 For radiotherapy of the oral cavity, typically ____ Gy is administered for a weekly exposure of ____ Gy. The radiotherapy continues for ____ weeks until a total of ____ Gy is administered. In recent years, a new 3D technique called ______ has been used to control the dose distribution.

Question 74

33 What is the "Golden Window" for effects of therapeutic radiation on the oral cavity?

Question 75

33 The highest risk for effects of therapeutic radiation on the oral cavity is between ____ months after therapy.

Question 76

35 At doses of 60 Gy and greater, the fraction for Xerostomia to occur increases to ____.

Question 77

36 What are the three types of radiation caries?

Question 78

37 Therapeutic radiation does not affect ______ teeth, but may effect _____.

Question 79

38 At what Gy are stimulatory effects on osteoblasts seen?

Question 80

38 At what Gy is there death of chondroblasts and osteoblasts?

Question 81

38 At what Gy is a single dose in a young child that results in irreversible growth retardation and short stature?

Question 82

38 At what Gy is there radiation damage to mature, intact bone, a more radioresistant tisue?

Question 83

38 Osteoradionecrosis is a combination of what three things?

Question 84

39 If the muscles of mastication are involved in radiation effects, _____ may result. The ___ and _____ muscles are usually invovled.