Exam 1 Flashcards
(188 cards)
1
Q
anything that occupies space and has mass
A
matter
2
Q
results when matter is altered
A
energy
3
Q
substances made up of only one type of atom
A
elements
4
Q
central nucleus + orbiting electrons
A
atom
5
Q
core of atom, consists of protons and neutrons
- always positively charged
A
nucleus
6
Q
positively charged particles
A
Protons
7
Q
particles with no charge
A
neutrons
8
Q
tiny, negatively charged particles
- Arranged around nucleus in orbits
A
electrons
9
Q
pathway of electrons
A
Orbits (shells)
10
Q
number of protons and neutrons in nucleus
A
Mass number/Atomic weight
11
Q
number of protons in nucleus equals number of electrons in atom
A
Atomic number
12
Q
Maximum number of shells per atom
A
7
13
Q
1 KeV =
A
1000 eV
14
Q
attraction between the positive nucleus and negative electrons
- Keeps electrons surrounding nucleus
A
Electrostatic force
15
Q
amount of energy needed to remove electron from its orbit
A
Binding energy/force
16
Q
two or more atoms joined together by chemical bonds
A
Molecules
17
Q
sharing electrons in outermost shell
A
Covalent bonding
18
Q
transfer of electrons
A
Ionic bonding
19
Q
can exist as neutral or unbalanced
A
atoms
20
Q
(unbalanced atom) atom that gains/loses an electron and becomes electrically unbalanced
A
ion
21
Q
converting atoms into ions/production of ions, become positively or negatively charged
A
Ionization
22
Q
result of an electron being removed from atom, positive ion + negative ion
A
Ion pair
23
Q
emission and propagation of energy through space or substance in form of waves or particles
A
Radiation
24
Q
process of unstable atoms undergoing spontaneous disintegration to become balanced
A
Radioactivity
25
high energy capable of producing ions
Ionizing radiation
26
tiny particles of matter traveling in straight lines at high speed, may be charged
- HAS mass
Particulate radiation
27
- wave like motion
- NO mass
- Can be man-made or naturally
- Arranged on electromagnetic spectrum
Electromagnetic radiation
28
- discrete bundles of energy
- Photons
- No mass
- Travel as in straight line
Particle concept
29
- waves
- Focus on wavelength, frequency, velocity
wave concept
30
distance between crest of waves
Wavelength
31
number of wavelengths in specific time period
Frequency
32
wave speed
velocity
33
o Invisible
o No mass
o No charge
o Travel in waves and straight lines
o High frequency, short wavelength
o Cannot be focused to a point
o Penetrate gases, liquid, and solids
o Absorb matter
o Interact with matter, cause ionization
o Cause certain substances to fluoresce
o Can produce image on receptor
o Causes biological change in cells
Characteristics of X-rays
34
what does the metal housing in the tubehead do
protect everything
35
what does the insulating oil in the tubehead do
dissipates heat
36
what does the tubehead seal do
makes sure insulating oil is contained
37
what does the aluminum disks do in the tubehead
filters out long wavelength or low frequency x-rays
38
what does the lead collimator do in the tubehead
restricts size of x-ray beam
39
Supply electrons necessary to generate x-rays
Cathode (negative)
40
* Generates electrons
* Creates electron cloud
Tungsten filament
41
* Focusing electrons into one line
* Electrons always floating from cathode to anode!!
Molybdenum cup
42
- Convert electrons into x-rays
- Tungsten target
- Copper stem
Anode
43
needed to generate x-rays
electricity
44
flow of electrons through a conductor
Electrical current
45
electrons flow in one direction through conductor
Direct current
46
electrons flow in two, opposite directions
Alternating current
47
converting from AC to DC
Rectification
48
number of electrons moving through conductor
Amperage
49
speed of electrons moving from cathode to anode
Voltage
50
path of electrical current
Circuits
51
* Generates source of electrons needed to produce x-rays at filament of x-ray tube
* Controlled by mA settings
Filament circuit (3-5V)
52
* Provides high voltage required to accelerate electrons from cathode to anode
* Controlled by kV settings
High-voltage circuit (65,000-100,000V)
53
device used to increase or decrease voltage in an electrical circuit
Transformer
54
Decreases V
Step-down transformer
55
Increases V
Step-up voltage
56
Corrects minor fluctuations in current
Autotransformer
57
release of electrons from tungsten filament when electrical current passes through it and heats filament
Thermionic emission
58
* Aka breaking or bremsstrahlung radiation
* 70% of x-rays produced at anode
* High speed down when passing tungsten atom
* Hits: all kinetic energy converts to high-energy x-ray photon
* Misses: low-energy x-ray photon
General radiation
59
* 30% of x-rays
* High-speed electron dislodges inner-shell electrons from tungsten atom
* Causes ionization
* Electrons rearrange, causing loss of energy and production of x-ray photons
Characteristic radiation
60
penetrating x-ray beam
Primary radiation
61
result of primary beam interacting with matter, less penetrating than primary
Secondary radiation
62
form of secondary, deflected x-rays after interaction with matter going in all directions; detrimental
Scatter radiation
63
o Passes through atom unchanged and leaves atom unchanged
o Responsible for producing densities
o Makes dental radiography possible
No interaction
64
o Photoelectric effect
o Photon interacts with inner shell electrons of matter
o Photon is absorbed and electron is ejected
o Ionization occurs → BAD
Absorption
65
o AKA modified scatter
o Compton effect
o Photon interacts with outer shell electrons of matter
o Photon loses energy but electron still ejected
o Ionization still occurs → BAD
Compton Scatter
66
o AKA Thompson Scatter or unmodified scatter
o Photons interact with outer shell electrons, but matter is not altered
o Photons continue to travel with no loss of energy
- Direction changes with no energy loss
o No ionization occurs
Coherent Scatter
67
the study of the effects of ionizing radiation on living tissue to understand the harmful effects of x-radiation
Radiation biology
68
- Photoelectric effect or Compton scatter
- Results in positive atom and dislodged negative electron
- Ejected electron still in motion and interacts with other atoms
Ionization
69
- uncharged neutral atom/molecule that exists with one single electron in its outmost shell
- Highly reactive and unstable
Free radical formation
70
Cell damage can occur when ionizing radiation directly hits critical areas (cell death)
Direct theory (1/3)
71
X-ray photons absorbed within cell and cause formation of toxins (causing direct damage)
Indirect theory (2/3)
72
o Probability of occurrence increases with dose
o Severity is NOT dependent on dose
o All or none
Stochastic radiation effect
73
o Severity of damage dependent on dose
o Occur only after exceeding threshold
o Result of severe cell damage
Nonstochastic/Deterministic radiation effect
74
time to exposure to clinical signs
Latent period
75
time in which cellular injury occurs
Period of injury
76
time in which it takes for cell to repair itself
Recovery period
77
o Total dose
o Dose rate
o Amount of tissue irradiated
o Cell sensitivity
o Age
Determinants for radiation injury
78
- Seen within minutes, days, or week
- Large amount of radiation in short time
Short-term effects
79
- Appear after years, decades or generations
- Small amount of radiation over long period of time
Long-term effects
80
- All cells except reproductive cells
- Injury to person irradiated
- NOT passed to offspring
Somatic effects
81
- Reproductive cells
- Not seen in person irradiated
- Passed onto future generations
Genetic effects
82
o Blood cells
o Bone marrow
o Reproductive cells
o Intestinal mucosa
o Skin
o Lens of eyes
o Oral mucosa
Radiosensitive cells
83
o Muscle tissue
o Nerve tissue
o Mature bone/cartilage tissue
o Salivary glands
o Thyroid glands
o Kidney
o Liver
Radioresistant cells
84
Amount of radiation in air
Roentgen (R)
85
Roentgen (R)
Exposure
86
Amount of radiation absorbed by tissue
Radiation absorbed dose (rad)
87
Radiation absorbed (rad)
Dose
88
Measurement of the effect on tissue
Roentgen equivalent (in) man (rem)
89
Roentgen equivalent (in) man (rem)
Dose Equivalent
90
1 Gy =
100 rad
91
1 Sv =
100 rem
92
Medical radiation (medical imaging, dental imaging)
Synthetic
93
Risk of Cancer from dental imaging
3/1 million
94
risk of Random cancer
3300/1 million
95
Who discovered x-rays in 1895?
Wilhem Roentgen
96
German dentist
Otto Walkhoff
97
Energy carried by waves/particles
Radiation
98
high-energy radiation produced by a collision of a beam of electrons with a metal target in an x-ray tube
X-radiation
99
energy that penetrates substances
X-ray
100
the study of radiation in medicine
Radiology
101
image produced on a receptor by exposure to ionizing radiation (2D image of 3D object)
Radiograph
102
Image created via x-rays passing through teeth
Dental radiograph
103
Art and science of making radiographs
radiography
104
production of radiographs of teeth and adjacent structures
dental radiography
105
person who positions, exposes, and processes dental x-ray image receptors
Dental radiographer
106
picture of an image
Image
107
recording medium
image receptor
108
creation of images of dental anatomic structures for diagnostic purposes
dental imaging
109
What houses the x-ray tube?
Tubehead
110
What restricts size of x-ray beam?
Position-Indicating device (PID)
111
What houses electrical wires and allows for movement?
extension arm
112
What regulates x-ray beams?
Control panel
113
What do we control on the control panel
timer
kilovoltage
milliamperage
114
What makes sure PID is lined up properly?
Beamaliment device
115
The dark/black portion of a radiograph
Radiolucent
116
Light/white portion of radiograph
Radiopaque
117
Overall darkness of an image
density
118
Difference in degrees of blackness on a an image
Contrast
119
Never intersect
parallel
120
lines cross at some point
Intersecting
121
cross directly in the middle
perpendicular
122
imaginary line that dives tooth in half
long axis of tooth
123
central portion of the primary beam of x-radiation
central ray
124
distance between tooth and receptor
object receptor distance
125
distance between x-ray source and receptor
target-receptor distance
126
What x-ray equipment do we use?
XCP-ORA
127
what are the advantages of paralleling?
accuracy
simplicity
duplication
128
what are the disadvantages of paralleling?
receptor placement
discomfort
129
What radiograph examines crown of maxillary and mandibular teeth?
bitewings (BMX)
130
What radiograph examines the crown, CEJ, root apex, and surrounding areas?
periapicals
131
What radiograph is used mainly for the diagnosis of dental caries?
Bitewings
132
What radiograph is mainly used to detect periodontal disease, pathology, endodontic therapy, and implants?
Periapicals
133
What radiograph examines large areas of maxilla and mandible?
occlusal
134
disease causing microorganism
pathogen
135
pathogens in blood
bloodeborne pathogens
136
objects that penetrate skin
sharps
137
waste including blood, blood products, contaminated sharps, microbiologic products
Infectious waste
138
substance inhibiting growth of bacteria
Antiseptic
139
chemical/physical procedure to inhibit or destroy pathogens (does not kill spores)
disinfect
140
chemical/physical procedure to destroy all pathogens (includes resistance bacteria and spores)
sterilize
141
absence of pathogens
asepsis
142
contact with blood/infectious material involving skin, eye or mucous membranes resulting from procedure performed by dental professional
Exposure incident
143
exposure from piercing or puncturing skin
Parenteral exposure
144
standard of care designed to protect personal and patients from pathogens
standard precautions
145
o Direct contact with
contaminants
o Indirect contact
o Direct contact with
airborne
routes of disease transmission
146
What is the recipe for infection?
Susceptible host
o Pathogen
o Portal
147
routine handwashing, antiseptic handwashing, antiseptic hand rub
methods of hand hygiene
148
The sensor is oriented ______ when exposing a posterior periapicle?
Horizontally
149
What are the three principles of paralleling technique?
1. receptor has to be parallel to long axis of tooth
2. central ray must be directed perpendicular to the long axis of tooth and receptor
3. A beamalime device must be used to maintain parallelism
150
How many mSv of radiation can an occupational exposed person be exposed to each year?
50 mSv
151
What are the two mechanisms of radiation injury?
Ionization
Free radical formation
152
If subject thickness is increased, how will the image appear?
Darker
153
X-ray machines operating above 70 kVp should have how many mm of aluminum filtration?
2.5 mm
154
What type of interaction occurs when an x-ray photon interacts with an inner shell electron and causes ionization?
Absorption
155
An x-ray beam should be no longer than how many inches after exiting the PID?
2.75 inches
156
Name five characteristics of x-rays.
Invisible
No mass
No charge
High frequency
Absorb matter
157
Would a deep large dose of radiation be more likely to cause short or long term effects?
Short term effects
158
What measurement determines the amount of radiation in the air, and what are the units?
Exposure
Roentgens
159
What type of radiation results when the primary beam interacts with matter?
Secondary radiation
160
What does ALARA stand for?
as low as reasonably achievable
161
Decreasing target receptor distance will result in what to the final image?
Image magnification and loss of definition
162
An exposure to contaminants by piercing or puncturing the skin is called what?
Parenteral exposure
163
What measures the speed of electrons moving from cathode to anode?
Voltage or kilovoltage
164
The central ray of the x-ray beam not being centered on the receptor will cause what error?
Cone cut
165
What are the four critical organs?
Thyroid gland
bone marrow
skin
lens of eyes
166
Are somatic effects seen in the person irradiated or their children?
person irradiated
167
Who prescribes dental radiographs?
dentist
168
How often should an adult with high caries risk get radiographs done?
every 6-18 months
169
How often should children with low caries risk get radiographs done?
every 12-24 months
170
What is the protection equipment of the tubehead?
Filters
collimators
PID
171
primary beam passes through glass window, insulating oil, and tube head seal
Inherent filtration
172
How much aluminum is in inherent filtration?
0.5-1.0mm
173
aluminum disks between tube head seal and collimator
added filtration
174
How many increments in added filtration?
0.5mm
175
inherent + added filtration
total filtration
176
What are the guidelines for less than or equal to 70 kVp of total filtration?
1.5mm aluminum filtration
177
What are the guidelines of greater than 70 kVp of total filtration?
2.5mm aluminum filtration
178
o Lead plate with hole or
beam
o Restricts beam size and
shape
o Reduce patient exposure
o Round or rectangular
Collimation
179
What is the length of a short x-ray beam?
8 inches
180
What is the length of a long x-ray beam?
16 inches
181
protect any blood forming and reproductive tissues from scatter radiation
lead apron
182
protects thyroid gland from scatter radiation
thyroid collar
183
most effective method of exposure
digital imaging
184
What is the fastest speed film?
F
185
radiation emitted from tube head that is not the primary beam
leakage radiation
186
- measures amount of radiation reaching the body of radiographers
- waist level or higher
personnel monitoring
187
What is the maximum radiation dose per year for a non-occupationally exposed person?
1 mSv
188
What is the maximum radiation dose per year for pregnant persons?
0.5 mSv
