Ch. 7 Cellular Biology Flashcards
____- consists of 2 Protons and 2 Neutrons; very heavy; causes superficial/skin damage; can be stopped by black construction paper.
Alpha Particle
____- instability of an atom caused by addition or removal of electron/s.
Ionization
____- amount of energy deposited in tissue over path of radiation beam.
Linear Energy Transfer (LET)
Low ___ radiation deposits little energy in tissue; ex,
x-ray and gamma rays.
Low LET radiation
High ___ radiation deposits greater energy in tissue; ex, alpha.
High LET radiation
____- is potentially dangerous if implanted (Prostate Seeds) or ingested, injected, pr inhaled in Nuclear Medicine.
High LET
____- relative damage to tissue due to radiation being deposited.
Relative Biologic Effectiveness (RBE)
__ and __ are directly proportional.
LET and RBE
“Radiation Absorbed Dose” used to measure amount of radiation deposited in ANY object-living or inanimate.
Trad.- Rad
SI- Gray (Gy)
“Radiation Equivalent to Man” used to measure radiation absorbed in HUMAN tissue only.
Trad.- Rem
SI- Seivert (Sv)
Measure ionization IN AIR or IN AIR EXPOSURE.
1 R= 2.58 X 10 -4 C/kg
Trad.- Roentgen (R)
SI- Coulombs/Kg. (C/kg)
Used to measure Radioactivity (usually Nuclear Medicine)
Trad.- Curie
SI- Becquerel (Bq)
__= RADS x Quality Factor (QF)
or SEIVERTS= GRAYS x Quality Factor (QF)
REMS
____- tissue irradiated under oxygenated or aerobic conditions is MORE sensitive to radiation than when irradiated under anoxic or hypoxic conditions.
Oxygen Enhancement Ratio (ORE)
____ is important in Radiation Therapy because healthy, oxygenated tissue may not require as much radiation to kill cancer cells.
Oxygen Enhancement Ratio (ORE)
____- young cells more vulnerable to radiation damage; ex,- stem, immature, precursor, undifferentiated cells.
Law of Bergonie and Tribondeau
__-action of damage to cells from radiation occurs 5% of the time (direct hit to DNA)
Direct Action
____-action of damage to cells from radiation occurs 95% of the time (due to Radiolysis of Water)
Indirect Action
____- can result in formation of FREE RADICALS (*) which are extremely unstable, can travel and cause point lesions away from area that was irradiated.
Radiolysis of Water
____- Hydroxyl Radical (OH) and Hydroperoxyl Radical (HO2)
Types of Free Radicals formed
__- combine to form Hydrogen Peroxide (H202) which is toxic to the cell.
Two Hydroxyl Radicals (OH*)
____- when radiation interacts with DNA and severs a side rail of the DNA ladder. Repair enzymes are capable of reversing some ____.
Point Mutaion
____- photomicrograph of chromosome that shows damage from radiation.
Karotype
____- mastermind of cell and necessary for cell survival.
DNA