Radiation Injury Flashcards
ionizing radiation injures cell by generating _______ from water or molecular oxygen
free radicals
xrays and gamma rays are ________ waves
electromagnetic
alpha, beta, and protons are energetic charged ________
particles
neutral high energy particles?
neutrons
a release of 2 protons and 2 neutrions from a fissioning nucleus, only travel a few mm in air, but internal exposure from ingestion is problematic
alpha radiation
emission of electrons, ionize matter they interact with, can travel several meters in air, cm in tissue, a few mm through aluminum
beta radiation
capable of generating ions in tissue, indirectly ionizing radiation, absorbed by nucleus then emits gamma radiation, penetrate more deeply into tissue
neutrons
disintegrations/second
curie (Ci)
quantity of X or g rays which give rive to certain number of ions in air
Roentgen (R)
100 ergs of energy absorbed per gram of any substance
RAD
new international unit replacing RAD
Gray (Gy)
new international unit replacing REM, houles of energy absorbed per kg
Sievert (Sv)
most important target of radiation?
DNA, dividing cells most sensitive
cells severely damaged by radiation undergo _________, surviving cells may harbor mutations or chromosome abnormalities
apoptosis
_______ is a long term effect of ionizing radiation
fibrosis
-erythema, hyper and hypo pigmentation, atrophy, fibrosis, telangiectasias
short term effect of radiation on skin (peak at 2-3 weeks)
long term effect of skin exposure to radiation?
squamous cell carcinoma
effects of radiation on bone and soft tissue?
long term risk of sarcoma
why don’t surgeouns want to operate on previously irradiated areas?
chronic vascular injury –> fibrosis –> poor vascularity –> poor wound healing
atomic bomb uses _______, hydrogen bomb uses _______
fission
fusion
radioactive material gets pumped into atmosphere, then falls out later
radioactive fallout
-major hazard of fallout b/c incorporated into bone, long half life, consumption of dairy and fruits and veggies major route of contamination
strontium
produces greatest internal exposure in weeks following nuclear explosion, eaten by meat animals and secreted in the milk, concnetrates in thyroid gland, half life 8 days
iodine
constituent of dirty bomb, damages gonads
cesium
useful for dating ancient objects, dangerous component of nuclear fallout
carbon 14
- molecular death (>100K)
- CNS (>2K)
- GI (50-2K)
- Hematopoietic (50-500 RAD)
- prodromal, such as cancer (<50)
acute radiation syndromes
- NVD resolves in 1-2 days
- tx: bone marrow transplant
- late: observe for development of post radiation cancers
hematopoietic syndrome
- death in a few days from circulatory collapse
- n/v/d
- no treatment except those w/ lower dose
GI acute radiation syndrome
only the ______ syndrome can be effectively treated, BMT, early HLA typing
hematopoietic
