Physics 2 test 3 Flashcards
(152 cards)
1
Q
At nearly every stage in the sequence of events after radiation exposure to human cells, it is possible or not possible to repair radiation damage and recover?
A
Possible
2
Q
The study of the effects of ionizing radiation on biologic tissue
A
Radiobiology
3
Q
Radiation interacts in the human body at what level
A
Atomic level
4
Q
What percent of the body consist of hydrogen and oxygen?
A
85%
5
Q
What percent of the body is water?
A
80%
6
Q
What does it mean to fractionate radiation exposure?
A
To give small amounts over a period time, versus all at once in one setting.
7
Q
What does it mean to Protract radiation exposure?
A
Spread out a single large dose continuously at a slower and lower rate.
8
Q
What is extrapulation?
A
Scientifically theorizing results to exposure
9
Q
Very large molecules that sometimes consist of hundreds of thousands of atoms
A
Macromolecules
10
Q
Four of the five principle molecules found in the body are
A
Proteins
Lipids (fats)
Carbohydrates (sugars and starches)
Nuleic acids
11
Q
What type of molecules are life supporting and contain carbon?
A
Organic Molecules
12
Q
Which molecules make up Organic Molecules?
A
Proteins
Lipids
Carbohydrates
13
Q
This molecule is one the rarest molecules, a nucleic acid concentrated in the nucleus of a cell and is the most critical and radiosensitive target molecule.
A
DNA
14
Q
Most abundant molecule in the body and simplest
A
Water
15
Q
The body’s attempt to maintain a constant internal environment through perspiration and replacement
A
Homeostasis
16
Q
The breaking DOWN of molecules ending in water an carbon dioxide
A
Catabolism
17
Q
The PRODUCTION of large molecules
A
Anabolism
18
Q
Catabolism + Anabolism
A
Metabolism
19
Q
Long chain macromoleucles that consist of a linear sequence of amino acids connected by peptide bonds
A
Proteins
20
Q
Proteins make up what percent of the human body
A
15%
21
Q
Name the variety of uses Proteins provide the body
A
Structure and support
Function as Enzymes, hormones and antibodies
22
Q
A catalyst which speeds up reactions
A
Enzymes
23
Q
Molecules that excersise regulatory control over some body functions such as growth and development
A
Hormones
24
Q
Hormone molecules are produced and secreted by what?
A
Endocrine glands:
Pituitary, adrenal, thyroid, parathyroid, pancreas and gonads
25
The body's defense system
Antibodies
26
Molecules that consist of one molecule of gycerol and three molecules of fatty acid
Lipids
27
Lipids are composed of what?
Carbon, hydrogen and oxygen
28
Lipids are a part of cell membrane in what body tissue?
EVERY body tissue
29
Lipids are
Thermal insulation ( just under the skin) and a Secondary energy source-easier to get to energy from than carbohydrates
30
What is the cheif function of carbohydrates in the body?
To provide fuel for cell metabolism
31
Carbohydrates are also called
Saccharides
32
What are the two sugars in Carbohydrates
Monosaccharides and Disaccharides
33
Plant startches and Animal Glycogen
Polysaccharides
34
Chief cell function of carbohydrates
Cell Metabolism
35
A simple sugar, is main fuel for body
Glucose
36
Glucose is composed of what?
Carbon, Hydrogen and Oxygen
37
What is the ratio of hydrogen to oxygen in glucose?
2:1 *same as water molecules, hydrated water*
38
Two principle Nucleic Acids important to human metabolism
Deoxyribonucleic Acid- DNA
| Ribonucleic Acid- RNA
39
Resides in the nucleus, control center for cell and contains cell hereditary info
DNA
40
Extrememly large and complex macromelecules are
Nucleic Acids
41
Mostly in cytoplasm, there are two types of this and messenger and transfere
RNA
42
Describe Nucleotides
Base-sugar-phosphate combinations strung together. two chains attach at bases and then spiral to form DNA
43
Bases of Nucleotides are allowed in only two combinations
Adenine + Thymine
or
Cytosine + Guanine
44
The order of base combinations in DNA carries what
Genetic code
45
Basic component of all living material
Human Cell
46
The two major structures of the human cell are
Nucleus and Cytoplasm
47
The principle molecular component of the nucleus is
DNA
48
Other than DNA what else if contained in the nucleus
RNA
Protein
Water
49
(Blank) makes up the bulk of the cell and contains great quantities of all molecular components except (blank)
Cytoplasm
| DNA
50
The (blank) is a channel or series of channels that allows the nucleus to communicate with the cytoplasm.
Endoplamic Reticulum
51
Located in the cytoplasm (blank) are large bean-shaped structures. Their purpose is to provide (blank) for the cell
Mitochondria
| Energy
52
These small dot like structures are located throughout the cytoplasm or the (blank). (blank) are the site of protein synthesis.
Endoplasmic reticulum
| Ribosomes
53
(blank) are small pea-like sacs that contain (blank) that help with cellular digesting.
Lysosomes
| enzymes
54
The normal number of chromosomes in a human cell
46
55
Ocupational radiation is measured in what?
mR milli rad
56
Mammalian cells may be killed by doses of less than (blank) rad or (blank) Gy
100 rad
| 1 Gy
57
What part of the cell is most sensative to radiation and why
DNA because you only have to much
58
If radiating cytoplasm and not the nucleous, how much radiation in rad and Gy could it take for cellular death
1000 rad or 10 Gy
59
If something is avascular it means what in relation to blood supply and radiation treatment and why?
Not a good blood supply
Not very responsive to treatment such as Chemo, meds etc
Oxygen is carried through the blood, if the blood supply is low, oxygen is low and oxygen is key for treatment
60
Because DNA is the most radiosensative part of the cell, the faster a cell replicates the (blank) radiosensative it is.
More
61
Describe Mitosis
Cell swells up, chromosomes lines up, Chromosomes split and migrate toward nucleus
62
In radiology what process of cell reproduction are we most concerned with
Interphase
63
Describe interphase
The part of cell reproduction that varries in time from cell to cell. Ths is where DNA is replicating.
64
Most radiosensative cells are and whats different about them from other human cells
Sperm and Ovary
Spermatogonium and Oogonium
They go through Meiosis versus mitosis
65
The less mature a cell or cell system the (blank) sensative
More
66
Reproductive cells go through regualar mitosis where you have two cells alike, then those two cells do what...and the end result is what?
Divide again without going the "S" phase so they do not synthesis DNA. End result you have four cells with 23 chromosomes each
46-46-23/23 and 23/23
67
Undifferentiated, presursor or stem cells are concidered what kind of cells? Are these cells more or less radiosensitive than mature cells?
Immature cells
| More
68
Cells, tissues and organs that are highly sensative take more or less radiation
Less
69
What type of cells have low sensativity?
Muscle, brain and Spinal (Nerve)
70
High metabolic acitivty means what in relation to reproduceability and radiosensitivity?
Rapid reproduction
| Highly sensitive
71
If you are fractionating radiation you are doing what?
Giving small doses over an extended period of time.
72
If you are protracting radiation you are doing what?
Giving continuous radiation over a longer period of time.
73
List the 9 things that affect radiation response
```
LET
RBE
Fractionation
Protraction
OER
Age
Sex
Recovery
Chemical agents
```
74
Define LET
Linear Energy Transfer: How much energy a given photon deposits in the tisue over distance (micrometer)
75
The more energy a photon gives up, the (blank) the LET
Higher
76
As LET increases, bioligic damage produced (blank)
Increases
77
About the rate at which diagnostic x-rays give up energy
3 keV per micrometer
78
Degine RBE
Relative biologic effectiveness: The effectiveness of LET radiation
79
As LET (ability to transfer energy to tisue) goes up, RBE goes (blank). Is this directly proportional?
Up
| no
80
When do RBE levels, level out? can't get any higher
3, triple the effect of diagnostic
81
What is the RBE of diagnostic x-rays and in what kVp range is this
1
| 20-130
82
How can you increase radiation tolerance? What effect if any do these have on biological effectiveness?
Use protraction or fractionation
| Either would reduce the biological effect of the exposure
83
As RBE goes up, LET goes (blank) and OER goes (blank)
Up
| Down
84
As OET goes up, RBE goes (blank) and LET goes (blank)
Down
| Down
85
Define OER
Oxygen Enhancement Ratio: A numerical descriptin of the effect oxygen has on tissue damage
86
What does the presence of oxygen do the the effectiveness of radiation?
Effectiveness goes up
87
Cells that duplicate faster are more radiosensitive-they have less time for repair before time to divide again. This means they are more likely to to be hit during what cell division phase?
Mitosis
88
In vitro irradiation occures (blank) the body or (blank) the cell
Outside
89
In vivo irradiation occures
In the living cell
90
In vitro or In vivo are more radio-sensitive
In vivo
91
Major radiation responses of DNA (5) and viscosity results
```
Main-chain scission:
sever one side rail-thinner
sever both side rails-thinner
with cross-linking-thicker
Point lesions
Change or loss of base
```
92
Which radiation response to DNA is more likely to cause a mutation?
Main-chain scission with cross-linking
93
Difference between direct and indirect hits of radiation to DNA
Direct-hit the actual DNA
In direct-hit water and then effected the DNA
Doesn't matter which is hit, the end result is the same.
94
3 types of damage to DNA
Cell death
malignant disease
genetic damage
95
Describe radiolysis of water
Water that has been irradiated dissociates into other molecular products.
Breakingdown of water
96
What happens to an atom of water that is irradiated?
It ioizeses and dissociates into two ions-an ion pair H+ and OH- and two free radicals
97
Describe a free radical
Unchaerged molecule that contains a single unpaired electron in the outer shell. Short life span.
98
How is hydrogen peroxide in relation to free radicals
The OH* free radical can join with a similar molecule to form hydrogen peroxide.
Hydrogen peroxide can also be formed with two hydroperoxyl free radicals
99
The principal damaging products after radiolysis of water
Hydrogen peroxide and hydroperoxyl radical
100
Describe a hydroperoxyl radical
H* interacting with an oxygen molecule
101
Priciple action of radiation on humans is (blank)
Indirect
102
Target Theory
There are key sensitive molecules that no other colecules can pick up the work of if damaged to the point of non-function.
103
What is the target molecule
DNA
104
What must happen for cell death to occur
The target molecule must be damaged to the point it ceases to function
105
Describe a "hit"
An ionization that inactivates the target molecule (DNA)
106
What probability of a "hit" does high LET radiation ionization have?
High
107
Will adding or increasing oxygen with a high LET dose increase the liklihood of a "hit"?
No
108
Low LET radiation ionization does or does not get many "hits"
Does not
109
What happens to the likelihood of a "hit" when you add oxygen to low LET?
Increases the liklihood giving a greater area of effectiveness
110
As dose increases inactivity damage likelihood (blank)
increases
111
How are lethal effects of radiation determined?
By observing cell survival NOT cell death
112
What is D37
The amount of radiation that if uniformly distributed would be enough to inactivate ALL the cells exposed (kill all the cells)
The 37 represents 37% of the cells hit would survive
113
A specimen with a LOW D37 is (blank) radiosensitive.
Highly-doesn't take a large dose to kill 63% of cells
114
A HIGH D37 means the specimen has (blank) radiosensitivity
Low-takes a good bit of radiation to inactivate 63% of cells exposed
115
Complex organisms like human cells require two or more "hits" to inactivate a cell. This is known as
Multitarget, single "hit" theory
116
In what phase of mitosis are cells most resistant to radiation exposure? and why?
Late S phase-have double/extra DNA
117
3 stages of Acute Radiation Syndromes
Prodromal
Latent
Manifest Illness
118
What happens in Prodromal?
Immediate, brief, acute symptoms seen at min dose of 100 rad (1gy)
119
What happens in Latent?
Symptom free hours to weeks with from greater than 5000 rad, to 100-500 rad
120
Manifest Illness
Acute, lethal symptoms
121
Hematologic effects of radiation exposure
```
200-1000 rad (2-10 Gy)
reduced cell count
manifested by vomiting, mild diarrhea, malaise, lethargy, and fever
pt MAY recover
4-60 days (dose Depentent)
```
122
Gastrointestinal effects of radiation exposure
1000-5000 rad (10-50 Gy)
Death within 4-10 days (Dose Independent)
nausea, vomiting, and diarrhea
123
Central Nervous System (CNS)
Over 5000 rad (50 Gy)
Death within hours to 3 days (Dose Dependent)
Disoriented, seizures, lethargy, coma, death
elevated fluid in brain increases intracranial pressure
124
What is LD 50/30
Dose response for human lethality
threshold, nonlinear
Dose that will kill 50% of subjects within 30 days
For humans about 300 rad (3 Gy)
125
Damage to (blank) cells results in the earliest manifestation of radiation injury to the skin
Basal Cell
126
Erythema
Sunburn like reddening
127
Desquamation
Ulceration and Denudation
128
Epilation/Alopecia
Hair loss
| could temporary or permanent
129
Erythema dose that will be created in 50% of the people irradiated
@600 rad (6Gy) for humans
130
Gonadal exposure
Responses documented at doses as low as 10 rad (.1 Gy)
131
Ovarian exposures:
(blank) may suppress menstruation
(blank) may increase genetic mutations
(blank) temporary sterility
(blank) permanent sterility
```
10 rad (.1 Gy)
25-50 rad (.25-.5 Gy)
200 rad (2 Gy)
500 rad (5 Gy)
```
132
```
Testicular Exposure:
Sperm replace every (blank)
(Blank) reduces sperm count
(Blank) temporary sterility
(Blank) Permanent Sterility
```
```
Every 3-5 weeks
10 rad (.1 Gy)
200 rad (2 Gy)
500 rad (5 Gy)
```
133
Most Radiosensitive
Lymphocytes and Spermatogonia
134
Radiation-induced Chromosome aberrations follow a (blank) dose-response relationship
Nonthreshold
135
What is Cytogenetic analysis
The study of the genetics of cells, particularly cell chromosomes
136
What is a karotype
Chromosome map
137
Single hit chromosomes are (blank) and nonthreshold
Linear
138
Multihit chromosomes are (blank) and nonthreshold
Nonlinear
139
Reciprocal Translocations (Chromosomes)
No loss of genetic material, rearranged
140
Chromosome hit
Visible derangement, by then multiple DNA have been severed
141
Radiation safety guidelines and practices are based on linear or non linear, and threshold or nonthreshold dose-response
Linear
| Nonthreshold
142
Chromosome linear nonthreshold exposures can continue to show abnormalities for how many years after exposure?
20+
143
What can skin look like at the linear nonthreshold exposure dose?
Weathered, discolored and callused
144
Threshold for radiation induced cataracts?
1000+ rad (10+ Gy)
145
What pattern do radiation induced cataracts follow?
Threshold, nonlinear
146
What is the latent period for Radiation induced cataracts?
5-30 yrs of apparent well-being
147
1 rad is equal to how many MR
1000
148
What pattern does life span shortening follow with radiation exposure?
Linear, nonthreshold (no amount of radiation is safe)
149
What is the worse case senario for life span shortening?
Reduction of 10 days for every rad
150
Explain Relative Risk in relation to Radiation induced malignancies and genetic effects
One population was exposed, all the details of exposure are not known
151
Explain Absolute Risk in relation to Radiation induced malignancies and genetic effects
Two groups, one known exposure one "control" or non effected group, compare to each other
152
Explain Excess Risk in relation to Radiation induced malignancies and genetic effects
Cases above what would be expected in general population
