Definitely Definitions
Effects where the probability of them happening depends on the received dose, but severity of effect does not.
Stochastic (Probabilistic) effects
Temporary infertility is experienced at this dose.
2000 mGy
Stages of ARS are these.
1. Prodromal
2. Latent period
3. Manifest illness
4. Recovery or Death
Most radiosensitive stem cell in hemopoietic system.
Erythroblast
Concept of a dose being delivered continuously but at a lower dose rate.
Protraction
Biologic somatic effects of IR that are directly reflated to the dose received.
Deterministic (Nonstochastic) (Tissue reactions)
More than 50 Gy.
CNS syndrome
Syndrome where mean survival time is independent of dose received.
GI syndrome
Most radioresistant cell in hemopoietic system
Concept of dose delivered at same dose rate, but in equal portions at regular intervals.
Fractionation
Why does this work?
Dose of radiation that produces twice the frequency of genetic mutations as would be observed without radiation.
Doubling Dose
Life span shortening
10 days for 10 mGy
Severe damage to cells lining the intestine is principal cause death in this syndrome.
Gastrointestinal Syndrome
Most radioresistant cell types in the human body
Muscle cells and nerve cells
Chemical agent that enhances the effect of radiation.
Radiosensitizer
Effects of radiation on the embryo-fetus in utero that depend on the fetal stage of development and dose received.
Teratogenic effects
High doses within 2 weeks of fertilization, can result in this.
Spontaneous abortion or nothing.
Principle problem of hematopoietic syndrome
More bone-marrow cells destroyed, more susceptible to infection.
Most radiosensitive mature blood cell
Lymphocytes
Time period of human life when most radioresistant.
Maturity/ Adult
The number of cases of some stochastic effect that are seen in the population that can be attributed to radiation exposure that is over the expected number of cases.
Excess risk
2- 10 Gy
Hematopoietic syndrome
Signs and symptoms of CNS syndrome's manifest illness include:
Mental status changes, ataxia, difficulty breathing, lethargy, seizures, coma.
Increased intracranial pressure, vasculitis, and meningitis
The 4 rules of Bergonié and Tribondeau
1. Stem cells are radiosensitive; mature cells are radioresistant
2. Younger tissues and organs are radiosensitive
3. Tissues with high metabolic activity are radiosensitive.
4. High proliferation rate for cells and a high growth rate for tissue result in increased Radiosensitivity
Theory that a little bit of radiation is good for you
Hormesis