Radiation Biology Flashcards
This theory states that cell damage occurs when ionizing radiation passes through a structure, e.g. DNA of the cell
Direct theory of radiation injury
This theory states that cell damage occurs when cell absorbs x-ray and interacts with water, forming toxins through the reaction this formation of toxins will cause cell damage
Indirect theory of radiation injury
This biologic effect of radiation does not have a threshold dose
Stochastic effect
All cells of the body except sex cells are affected in this type of stochastic effect
Somatic effect
Reproductive cells of the body are affected in this type and may cause congenital abnormalities or mental retardation; happens during 2-9 weeks after conception
Genetic effect
This biologic effect of radiation has a threshold dose and is proportional to the dose received
Deterministic effect
What is the sequence of radiation injury?
- Latent period
- Period of injury
- Recovery period
Period from time of exposure up to the time before the biologic effects are seen
Latent period
Period where biologic effects or changes are seen or experienced
Period of injury
5 factors of radiation injury
- Total dose
- Dose rate
- Amount of tissue irradiated
- Cell sensitivity
- Age
Quantity of radiation received
Total dose
Dose per period of time
Dose rate
2 types of radiation effects
- Short term effects
- Long term effects
Acute radiation syndrome; immediate effects upon exposure to radiation. May include vomiting, diarrhea hair loss, hemorrhage, etc. after exposure to large amount of radiation
Short term effects
Associated with small amounts of radiation absorbed repeatedly over a long period of time
Long term effects
This is a radiation effect on cell wherein cells that are more frequently dividing are more prone to cell damage by radiation
Mitotic activity
This is a radiation effect on cell wherein undifferentiated cells or immature cells are more prone to radiation damage
Cell differentiation
This is a radiation effect on cell wherein cells with higher metabolism are more sensitive to radiation damage
Cell metabolism
Most radiosensitive cells in the body; which is why many people have leukemia
Lymphocytes
These cells are also radiosensitive
Reproductive cells
Cells that are most resistant to radiation
Osteocytes
Radioresistant structures
Bones, muscles, nerves
Traditional radiation measurements
Roentgen (R)
Radiation absorbed dose (rad)
Roentgen equivalent in man (rem)
SI system radiation measurements
Coulombs per kilogram (C/kg)
Gray (Gy)
Sievert (Sv)
