Apoptosis

Cell Survival Curve 

A classic method of displaying the sensitivity of a particular type of cell to radiation.

Chromosome Breakage

A double-strand break in same rung of the DNA molecular structure

Direct action

 namely, direct ionization and disruption of biomolecules, biologic damage occurs as a result of ionization of atoms on essential molecules produced by straight interaction with the incident radiation

Indirect action

 A multistage process that first involves the production of free radicals that are created by the interaction of the radiation with water (H₂O) molecules. 

Law of Bergonié and Tribondeau

states that the radiosensitivity of cells is directly proportional to their reproductive activity and inversely proportional to their degree of differentiation.

Linear Energy Transfer (LET)

The average energy deposited per unit length of track.

Mutation

The  loss or change of a base in the DNA chain represents a ...

Operator Enhancment Ratio (OER)

Point Lesion

rupture one of its chemical bonds and possibly sever one of the sugar–phosphate chain side rails, or strands, of the ladder-like molecular structure (single-strand break) 

radiation weighting factor (W_R)

used to calculate the equivalent dose (EqD) to determine the ability of a dose of any kind of ionizing radiation to cause biologic damage. 

 relative biologic effectiveness (RBE)

RBE of the type of radiation being used is the ratio of the dose of a reference radiation (conventionally 250-kVp x-rays) to the dose of radiation of the type in question that is necessary to produce the same biologic reaction in a given experiment

Target Theory 

states that when cell DNA is directly or indirectly inactivated by exposure to radiation, the cell will die.

Wave-partical duality 

  x-rays and gamma rays can also be referred to as a stream of particles called photons. streams of particles called photons, each of which has no mass and no charge.

Thrombocytes

platelets, initiate blood clotting and prevent hemorrhage.

Muscle tissue

contains fibers that affect movement of an organ or part of the body. Since muscle tissue cells are highly specialized and do not divide, they are relatively insensitive to radiation.

Reproductive death 

generally results from exposure of cells to doses of ionizing radiation in the range of 1 to 10 Gy_t.

Air gap technique 

alternative procedure to the use of a radiographic grid for reducing scattered radiation during certain examinations

Mitotic Delay

 the failure of the cell to start dividing on time.

Characteristics of ionizing radiation 

• Charge

• Mass

• Energy