radiation Biology Latte Effects Flashcards
Somatic effects of radiation
Cancers and genetic effect
show late effects of life shortening, leukemia and other cancers
reduction of expected life span result of accelerated aging
Leukemia has a relatively short delay time between radiation dose and it onset; an average of 5 years while other cancers have a latent period of 20 years
Genetic effect: mutation of very specific cells, namely the sperm or egg cells.
Radiation increases the spontaneous mutation rate but no new mutations.
Incidence of late effects dependent on
radiation dose
dose rate
age at the time of irradiation
state of health
Potential Heredity effect
No heredity effects of radiation have ever been observed.
Define Mutation
Relatively stable change in DNA of the cell nucleus.
Mutation in the germ cells of the body (ova & sperm) may lead to inherited effects to offspring. Mutations in somatic cells of the body may lead to effects in the individual.
3 stages of fetal development
developing embryo very vulnerable to adverse radiogenic effects
1.Pre-implantation- (0-9 days) time between fertilization of the egg and its implantation in the uterine wall. Fertilized egg is dividing.
Organogenesis- 10 days to 6 weeks - time during maximal formation of new organs
Fetal- 6 weeks to term- time of growth of performed organs. CNS is still highly undifferentiated in the fetus.
principal effects of in-utero irradiation are prenatal death, growth retardation, and congenital malformation
most sensitive fetal development stage for lethal effects of radiation
Organogenesis is the most sensitive stage to malformations at birth.
principal effects of radiation in humans during organogenesis are microcephaly and general growth retardation
Radiation effects on fetal development
Embryo sensitivity varies during gestation
no adverse effect level for malformation until 10 rad
no adverse effect level for retardation or decrease IQ until 10 rad.
