1
Q
Apoptosis
A
process of cell death
2
Q
Cell survival curve
low vs high
A
method of displaying the sensitivity of a cell type to the radiation
low - has shoulder of survival window ; high - no shoulder of survival
3
Q
Chromosome breakage causes death in what type
A
Cases like double strand breaks, repair enzymes cannot repair and cell death is more likely
4
Q
Direct action
A
photons and electrons damaging DNA directly
5
Q
Free radicals
A
Solitary atoms (hydrogen atom nonmolecular)
or
a combination of atoms (OH) that behave as single entities
6
Q
Indirect action
A
free radicals causing havok on DNA
(free radicals come from direct water molecules ionization) (radiolysis)
7
Q
Law of bergonie and tribondeau
A
higher dividing/least maturity/least specialization/highest reproductive activity cells are the most sensitive
8
Q
Linear energy transfer
A
Average energy deposited per unit length of track.
Measured in keV per micron
9
Q
Mutation
A
changes in DNA or loss of DNA patterns
may have accute consequences and be irreversible
10
Q
Oxygen enhancement ratio or oxygen effect
A
Enhancement of the therapeutic or detrimental effect of ionizing radiation due to the presence of oxygen
11
Q
Point lesion
what is it, low or high LET radiation, and what repairs it
A
radiation severing the sugar-phosphate chain rungs in DNA.
Occur with Low-LET radiation.
Repair enzymes can often reverse this
12
Q
Radiation weighting factor
A
Used to calculate equivalent dose to determine ability to cause biologic damage
13
Q
Radiolysis
A
dissociation of molecules by ionizing radiation. ( in water)
creating positive and negative free radicals which can damage DNA
14
Q
Relative biologic effectiveness
A
Describes the comparative capabilities of radiation with differing LET to produce a particular reaction.
15
Q
Target theory
A
radiation damage happens at specifically sensitive cellular points known as “targets” from discrete and random events.
16
Q
Wave-particle duality
A
Particles acting like a wave and a particle (redefine)
17
Q
What is radiobiology
A
Biology concerned with the effects of ionizing radiation on living systems.
18
Q
Areas of radiobiology study
A
- Sequence of events after absorption
- Action of the living system to compensate for consequences of energy assimilation
- Injury to living system from irradtion
19
Q
Characteristics of radiation
A
Charge
Mass
Energy
20
Q
To understand ionizing radiation causes injury and effects on tissue. What 3 essentials must be studied?
A
Linear energy transfer
Relative biologic effectiveness
Oxygen enhancement ratio
21
Q
Track
A
Path of radiation photons as they pass through medium and lose energy.
22
Q
Average energy calculation
A
Total energy deposited in medium ÷ total track length
23
Q
When LET increases, chance of a significant biologic response in the radiosensitive DNA ….
A
Increases
24
Q
Low LET radiation
A
Gamma
Xray
Electrons
25
High LET radiation
Alpha part
Ion of heavy nuclei
Charged particles released from interactions between neutrons and atoms
Low energy neutrons
26
High LET radiation is of most significant a concern when internal contamination happens or when... (3)
A radionuclide has been
Implanted
Ingested
Injected
Inhaled
27
What happens to irradiated oxygenated tissue
More likely to recieve biologic damage
(Anoxic = 3x more resistant than well oxygenated)
28
Hypoxic vs anoxic
Anoxic = no oxygen
Hypoxic = some oxygen
29
Three levels of damage analyzation
Molecular
Cellular
Organic systems
30
# type of covalent cross link or "sticky"
what is the intrastrand cross-link
cross linking in two places on the same DNA strand
31
what is covalent cross linking
| high/low let difference
two or more molecules joined by a covalent bond which is sharing one or more pairs of electrons between the molecules
| high - caused by direct action ; low - caused by indirect action
32
what do chromosomal fragments do
after breakage, fragments are especially sticky and often:
-region in their original configuration
-join to other broken fragments and creaqte new chromosomes that don't appear altered compared to pre-radiation dna
33
# 2
chromosome abnormalities seen at metaphase
-chromosome aberrations
-chromatid aberrations
| chromosome is before DNA formation; chromatid is after DNA formation
34
# 7 things (SAAAMMC)
radiation causes what harmful effects to cell nuclei
-single strand break in 1 chromosome
-a break in 1 chromatid
-a single-strand break in seperate chromosomes
-a break in seperate chromatids
-more than one break in the same chromosome
-more than one break in the same chromatid
-chromosome stickiness/clumping
35
# (4) RDBB
consequences to cell from structural changes in nucleus
| these are all mutation types
1. restitution (rejoin, no damage)
2. deletion (chromosome parts are lost in next duplication)
3. broken-end arrangement (misshapen chrommosome may be made)
4. broken-end rearrangement without visible damage to the chromatids (genetics rearranged, but appears normal)
36
damage to cell nucleus is revealed by which actions:
1. instant death
2. reproductive death (can't procreate)
3. apoptosis/programmed cell death (cells die before division per can't complete cell cycle)
4. mitotic or genetic death (dies after 1 or more divisions)
5. mitotic delay (the failure of the cell to start dividing on time)
6. interference with function (repair enzymes can't fix it)
37
most radiosensitive blood cells
lymphocytes
38
fetus radiation damage can cause what 3 thigns
CNS anomalies, microcephaly, and intellectual disability
39
relatively insensitive adult cells
muscle
neuron
40
relatively sensitive adult cells
germ cells, epithelial tissue
| technically fetus = very sensitive
41
small Base pair lesion
| common?
breakage of the ladder rung of the DNA
| common, easily repaired
42
single strand break
| common?
break of of side of the dna strand
| common, easily repaired
43
double strand break
| common?
break of both sides of the dna
| least common, hardest to repair
44
is direct or indirect action more likely for dna damage?
indirect
## Footnote
it's more likely to be in a fire cused by lightning than to be hit by lightning
45
late effect vs early effect of radiation
effects manifest soon after = early
effects manifest long after = late
46
early effects...
skin erythemia
hair loss
sterilization
diminished sperm count
ARS (acute radiation syndrome)
infertility
## Footnote
these are also deterministic because they happen after a specific threshold has been reached
47
late effects...
cancer
cataracts
48
latency period of leukemia and solid tumors
leuk - 5-7 years after
solid tumors - 10-60 years
49
Acute Radiation Sundrome (ARS) and three syndromes associated
Occurs in humans after large whole body doses over several hours to a few days.
(Hiroshima and nagasaki, marhsall islanders, cherynobl, and radiation therapy)
1. Hematopoeitic synd
2. Gastroinstestinal synd
3. Cerebrovascular synd
50
Biologic dosimetry
Analysis where damaged tissue is used to estimate exposure/dose
51
Cytogenetic
The study of cell genetics (chromosomes) uses a chromosome.map called a karyotype
52
Desquamation
53
Early tissue reaction
Vary depending on duration of time after exposure (minutes hours days weeks)
54
Epilation
Or alopecia. Hair loss.
55
Genetic effects
Effects on future generations due to irradiation of germ cells in pervious generations
56
Genetic mutations
Gy level sepress sperm
Mutations from genetic modifications from radiation
Comes from germ cell sensitivity
Doses as low as 0.1 Gy can supress sperm
57
Grenz rays
58
Karyotype
Map of chromosomes used in cytogenetics.
Uses a photomicrograph of the cells during metaphase
59
Latent period
GI
Cerebro
Doseage
Period after radiation exposure with no illness
(GI = several days)
(Cerebrovasular = 12 hours)
1-100 Gy
60
Manifest period
Period after radiation exposure where illness/damage becomes apparent
61
Manifest illness
62
Metaphase
When chromosomes are visible in cytogenetics and cell damage can be evaluated.
Chromosome/chromatid abberations (abnormalities in growth) can be seen in this phase
63
Pluripotential stem cell
The cell that all cells from the hematopoietic system stem from (erythrycytes, granulocytes, thrombocytes or platelets, lymphocytes)
64
Prodromal stage
And GI time frame/sympt.
And doseage level
Stage that is the beginning stage before latent after exposure
(GI = 24 hours with nausea and diarrhea)
1 Gy
65
Radiodermatitis
Radiation caused skin damage or redness and burns
66
Somatic effects
Effects upon the body that was irradiated
67
Somatic tissue reactions
early somatic radiation effects that include cell killing and are directly related to dose recieved
68
Possible high dose consequences:
Nausea
Fatigue
Erythemia (red skin)
Epilation (loss of hair)
Blood disorders
Intestinal disorders
Fever
Dry and moist shedding of skin
Depressed sperm count
Temp sterility
CNS injury
69
What dose of Gy(t) offten coorelates with radiation damage side effects or ARS
6 gy
70
When do the three syndromes of ARS occur (how much dose required)
1. Hematapoeitic 1-10 Gy(t) *survival time shortens as dose ^*
*6-8 weeks before dying for 2 Gy dose*
2. Gastro (starts at 6 Gy and peaks after 10 Gy) *may die 3-10 days after exp even with medical help*
3. Cerebrovascular (50 Gy or more) *death within a few hours to 2-3 days*
71
Manifest illness
Illness manifest after radiation exposure
(Gastro intestinal = nausea, vomit, diarhhea, fever, fatigue)
(Cerebrovasc = nervousness, confusion, nausea, vonit, diarrhea, loss of vision, feinting, burning sensation of skin)
72
What is the most severely effected section of the GI tract in gastrointestinal disease?
Small intestine
73
What did LD 50/30 mean
What is the dose?
Means whole body dose of radiation that can be lethal to 50% of population within 30 days.
3.0-4.0 Gy
74
LD 10/30, LD 50/60, and LD 100/60
These lethal measures refer to the percent of subjects who die after a specified number of days.
75
LD 50/60 meaning whats the 50 and whats the 60
50 means 50%
60 means after 60 days
50% of population will die after 60 days after a lethal whole body dose
76
Factors for tissue or organ response to radiation exposure
Radiosensitivity
Reproductive characteristics
Growth rate
77
Tissues that suffer immediate consequences from high radiation dose:
Skin
Male and Female reproductive organ
Bone marrow
78
What of the female follicles are the most radiosensitive?
Intermidiate sized due to less specialization and acyively growing
79
Early tissue reactions are common in diagnostic radiology
T/f
False
80
When cells are exposed to sublethal doses of ionizing radiation, repair and recovery are possible.
T/F
True
81
All three skin tissue layers are involved in radiation dose
T/F
True
82
In females, how much gonadal dose will supress menstration?
0.1 Gy
83
if a person recieves radiation exposure sufficient to cause the gastrointestinal syndrome, fatality occurs primarily because of...
catastrophic damage to the epithelial cells that line the gastrointestinal tract, resulting in death from a combination of infection, fluid loss, and electrolytic imbalance.
84
For persons with hematopoietic syndrome, survival time shortens as the radiation dose
increases
85
what are the forms of ARS?
hematopoietic syndrome
cerebrovascular syndrome
gastrointestinal syndrome
86
Some local tissues suffer immediate consequences from high radiation doses. Examples of such tissues include
bone marrow,
male and female reproductive organs
skin
87
Atrophy
shrinkage of organs and tissues after a high radiation dose is received.
88
What determines the rate of production of chromosome aberrations?
1. The total radiation dose given to a somatic cell
2. The total radiation given to a genetic cell
3. The period of time in which radiation dose was delivered
89
Which of the following are classified as early tissue reactions of ionizing radiation?
Nausea, epilation, and intestinal disorders
90
Research has shown that repeated radiation injuries have a ____ effect
cumulative
91
The hematopoietic form of acute radiation syndrome is also called the
bone marrow syndrome
92
Organ and tissue response to radiation exposure depends on factors such as
1. radiosensitivity.
2. reproductive characteristics.
3. growth rate.
93
a single dose of 2 Gy can cause radiation induced skin erythema within... hours after irradiation
24-48
94
The correct order of development of the male germ cell from the stem cell phase to the mature cell is
spermatogonia, spermatocyte, spermatid, sperm.
95
Chromosomal damage can be caused by what types of LET radiation?
low and high radiation doses
96
During cardiovascular or other therapeutic interventional procedures that use high-level fluoroscopy for extended periods, the effects of ionizing radiation on the skin are at most... (significant, moderate, noexistant)
significant
97
Moist and dry desquamation can be caused by what doses of radiation
high
98
Data from epidemiologic studies of human populations exposed to doses of ionizing radiation sufficient to cause this acute radiation syndrome have been obtained from....
1. atomic bomb survivors of Hiroshima and Nagasaki.
2. Marshall Islanders who were inadvertently subjected to high levels of fallout during an atomic bomb test in 1954.
3. nuclear radiation accident victims, such as those injured in the 1986 Chernobyl disaster.
4. patients who have undergone radiation therapy.
all of the above
99
Grenz rays (low energy x-rays) were once used to treat and successfully cure
skin diseases such as ringworm
100
During the major response stages of acute radiation syndrome after the prodromal stage, the period when symptoms that affect the hematopoietic, gastrointestinal, and cerebrovascular systems become visible, is called
manifest illness
101
low-LET radiation(s)?
xray
gamma ray
electrons and positrons
102
least radiosensitve cells
adult nerve cells
103
most radiosensitive cells
lymphocytes
104
Which of the following humans is most radiosensitive?
- An embryo-fetus during the first trimester of pregnancy
- A 5-year-old child
- A fetus during the third trimester of gestation
- A mature adult
An embryo-fetus during the first trimester of pregnancy
105
indirect radiation is caused by....
free radicals
106
concerning patients who receive radiation exposure from a routine radiographic procedure such as a chest x-ray...
will patients sustain appreciable damage to blood or blood forming organs as part of the exam?
Patients are not expected to sustain appreciable damage to either the blood or the blood-forming organs as a consequence of the examination.
107
Direct action may occur after exposure to any type of radiation, but it is much more likely to occur after exposure to... high/low LET radiation
HIGH (alpha particles)
108
When LET increases, the chance of a significant biologic response in the radiosensitive DNA macromolecule
increases
109
Neutrophils and granulocytes play an essential role in
fighting infection
110
Which of the following tissues contain cells that do not divide?
1. Epithelial tissue
2. Muscle tissue
3. Nervous tissue in an adult
2 and 3
111
If bone marrow cells have not been destroyed by exposure to ionizing radiation, they can
repopulate after a period of recovery.
Xray School Cards
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Decks in class (30)
# Cards
-
Patient Care138
-
Pre Fall 2025394
-
1+2 Radiobiology63
-
Alimentary Canal A&P157
-
Computerized imaging34
-
3+4 Radiobiology73
-
HESI Practice Questions0
-
Anatomy Exam 246
-
Physics 5 + 6103
-
Anatomy Exam 393
-
Physics 7+8111
-
Biliary system test23
-
Urinary system test81
-
Chapter 9 + 1060
-
Section 2 Computed Imaging29
-
Section 3 Computed Imaging61
-
Chapter 11+12 Study55
-
Chapter 15 + 16125
-
reproductive unit22
-
Anatomy Final25
-
physics radiobio final prep cards67
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Total REVIEW65
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Quality53
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Quality SECTION 26
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Patient Care REVIEW83
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Safety REVIEW104
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Image Production Review215
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Medical Terms77
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Procedures Flash CARDS208
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Review COVERAGE273
