Comprehensive Exam Flashcards
the conversion of a neutral atom to a charged entity, called an ion, by removing one or more electrons from the atom or, in some cases by adding an electron to a neutral atom
Ionization
the number of protons (Z) contained within the nucleus of an atom
atomic number
the total mass of an atom, primarily consisting of the combined mass of its protons and neutrons, with a negligible contribution from electrons
atomic mass
occurs in humans after large whole-body doses of ionizing radiation delivered over a short period (from several hours to a few days)
Acute radiation syndrome
what are the three separate dose-related syndromes or conditions that occur as part of the acute radiation syndrome?
hematopoietic syndrome
gastrointestinal syndrome
cerebrovascular syndrome
Bone marrow syndrome, occurs when people receive whole-body doses of ionizing radiation ranging from 1 to 10 Gy. Radiation exposure causes the number of red blood cells, white blood cells, and platelets in the circulating blood to decreases. Dose levels that produce this syndrome may also damage cells in other organ systems and cause the affected organ or organ system to fail. Survival time shortens as the radiation dose increases. Death may occur 6 to 8 weeks after irradiation in those who receive a whole body dose just exceeding 2 Gy
hematopoietic syndrome
Appears as a threshold dose of approx 6 Gy and peaks after a dose of 10 Gy. Without medical support to sustain life, exposed persons receiving doses of 6 to 10 Gy may die 3 to 10 days after being exposed. Even if medical assistance is provided, the exposed persons will live only a few days longer, survival time does not change with dose in this syndrome. A few hours after the dose required to cause this syndrome has been received, the prodromal, or beginning stage occurs. next is the latent period and then the manifest illness stage follows
gastrointestinal syndrome
results when the central nervous system and cardiovascular system receive doses of 50 Gy or more of ionizing radiation. A dose of this magnitude can cause death within a few hours to 2 or 3 days after exposure. After irradiation the prodromal stage begins. The latent stage only lasts up to 12 hours
cerebrovascular syndrome
What is the “concept” of radiation protection?
ALARA
What procedures could cause the radiographer to receive a dose?
fluoroscopy, surgery
what is the radiation weighting factor (quality factor) for x-rays, gamma rays, and beta particles?
1
(1 Gy = 1 Sv)
what is the radiation weighting factor for alpha particles?
20
what has the highest penetrating capability?
gamma rays
______ particles are much less penetrating. (they have large interaction cross-section or scattering probability)
alpha
______ particles will not interact as strongly with their surroundings as do alpha particles, therefore they are capable of penetrating biologic matter to a much greater depth than alpha particles, with far less ionization along their paths
beta
SI units for absorbed, equivalent, effective dose, etc.
absorbed: mGy
equivalent: mSv
effective: mSv
what is the SI unit for absorbed does?
milligray (mGy)
(amount of energy that is deposited in a material per unit mass of the material)
what is the SI unit for equivalent does?
millisievert (mSv)
(type of ionizing radiation)
what is the SI unit for effective does?
millisievert (mSv)
(measure of general harm in humans, best overall measure of the biologic effects of ionizing radiation. takes into account the amount of absorbed dose and the type of radiation)
approximates the size of the anatomical area or part to be included in the radiation field
collimator, beam limiting device
restricts the size and shape of the x-ray beam so it does not exceed the size of the selected image receptor
positive beam limitation
used to assess the overall impact of a gonadal dose on populace. defined as the equivalent dose to the reproductive organs that, if received by every human in a large population group, would be expected to bring about an identical gross genetic injury to that total population, as does the sum of the actual doses received by exposed individual members of the population
Genetically Significant Dose
How do you write Gy, cGy, mGy: Its about the decimal point
1 Gy = 100 cGy = 1000 mGy
1 cGy = 0.01 Gy
1 mGy = 0.001 Gy
what are the 4 major classes of organic compounds?
proteins, carbohydrates, lipids, nucleic acids (all contain carbon as a fundamental constituent)
compounds that do not contain carbon. these compounds found in the body occur in nature independent of living things and are made up of 3 categories
inorganic compounds
what are the 3 categories of inorganic compounds?
inorganic acids, inorganic bases, salts (electrolytes)
this radiation includes alpha particles, beta particles, neutrons, protons. all of these are subatomic particles that are ejected from the nucleus of atoms at high speeds
particulate radiation