Dose Quantities
Absorbed Dose is
quotient of energy deposited by ionizing radiation to a mass
Ribosomes are described as
serving as the protein production machinery for the cell and are consequently most abundant in cells that are active in protein synthesis, such as pancreas and brain cells
Apoptosis
genetically ‘programmed’ form of cell death
Cancer is
A disease in which abnormal cells divide uncontrollably and destroy body tissue
Mass energy absorption coefficient
g represents the average fraction of initial kinetic energy transferred to electrons that is subsequently emitted as bremsstrahlung
KERMA is
quotient of the sum of the initial kinetic energy of all charged particles liberated by indirectly ionizing particles in a volume element
Centrioles
are cylindrical organelles that participate in cell division as microtubule organizing centers
Autophagy
a term that literally means ‘self eating’ and describes a process in which cells digest parts of their own cytoplasm in order to generate small macromolecules and energy
The mutations that contribute to the development of cancer affect three general classes of gene
1) oncogenes, 2) tumor suppressor genes, and 3) DNA repair genes.
ETr & EAb – Pair Production
EAb is difficult to determine
Equivalent Dose is
for tissue T and radiation R is the product of absorbed dose and the radiation weighting factor wR
The nucleus
contains the genetic material that directs cell metabolism
Most cell death after radiation occurs
late in response to mitotic catastrophe and not from the initial response to damage.
Charged particulate radiation is
directly ionizing
Head on collision results in
maximum energy transfer
Effective Dose
Different body tissues respond differently to radiation; thus, the probability for stochastic effect from HT,R depends on the tissue irradiated
Chromatin
consists of coiled DNA bound to basic proteins called histones
Mitotic catastrophe
the type of cell death that results from, or follows, abnormal mitosis
Electromagnetic radiation and neutrons are
indirectly ionizing
Heavy charged particles
tend to travel straight lines in matter
1 Gray is
1 Joule/kg
The mitochondria is
the power source of the cell and contain the molecular machinery for the conversion of energy
Cellular senescence
the term given to the observation that over time normal cells permanently lose their ability to divide
Compton Scattering
Probability dependent on material electron density (electrons/g)
Name some examples of types of scattering and absorption reactions that could be relevant in human tissue
elastic, inelastic, particle ejection, capture