Radiobiological effects Flashcards
What is it called when an ejected electron causes ionisation of other atoms
Secondary ionisation
What is it called when some of the free radicals produced by breaking bonds combine with others to form new chemicals within the cell
Chemical change
What is it called when there is abnormal behaviour of the cell
Biological change
Dna damage is immediate however
the effect on the actual cells is delayed
Hours or days after DNA damage occurs, cell damage may only appear when the cell tries to..
Divide but fails
If the cells can divide the next thing to happen is…
After many generations of divisions the daughter cells may reproduce in an uncontrolled way causing cancer.
Or the effect may produce a mutation in the DNA that affects…
future generations
Review of Absorbed dose definition and unit in relation to biological effects
Biological effects in any tissue are proportional to the amount of energy absorbed per unit of mass of tissue
Unit = Gray
Review of Equivalent dose in relation to biological effects
Different radiations have different biological effectiveness for the same amount of energy absorbed.
Unit = Sievert
Do x-rays and gamma ray cause much biological damage?
No, they are very penetrating and do not give up energy quickly
Effective dose calculations + review for biological effects
The effective dose to any organ = equivalent dose x Tissue weighting factor.
- Effective whole body dose = the sum of effective doses of the various organs.
