lecture 3 - radiation physics & radiation biology

Question 1

what is the maximum number of shells per atom

Answer 1

7

Question 2

what are the shells from highest energy to lowest energy

Answer 2

K, L, M, N, O, P, and Q

Question 3

binding force

Answer 3

energy required to remove an electron from its orbit shell must exceed the binding energy of the electron in that shell

Question 4

covalent bonding

Answer 4

sharing electrons in outermost shells

Question 5

ionic bonding

Answer 5

transfer of electrons

Question 6

ion

Answer 6

atom that gains/loses an electron and becomes electrically unbalanced

Question 7

ionization

Answer 7

converting atoms into ions/production of ions, becomes positively or negatively charged

Question 8

radiation

Answer 8

emission and propagation of energy through space or substance in form of waves or particles

Question 9

radioactivity

Answer 9

process of unstable atoms undergoing spontaneous disintegration to become balanced

Question 10

ionizing radiation

Answer 10

high energy, capable of producing ions

Question 11

what does wave concept focus on

Answer 11

wavelength
frequency
velocity

Question 12

wavelength

Answer 12

distance between crest of waves

Question 13

frequency

Answer 13

of wavelengths in a specific time period

Question 14

characteristics of x-rays

Answer 14

invisible
no mass or weight
no charge
travel in waves and straight lines
high frequency, short wavelengths

Question 15

primary radiation

Answer 15

penetrating x-ray beam

Question 16

secondary radiation

Answer 16

result of primary beam interacting with matter, less penetrating than primary

Question 17

scatter radiation

Answer 17

form of secondary, deflected x-rays after interaction with matter going in all directions; detrimental

Question 18

no interaction

Answer 18

passed through atom unchanged and leave atom unchanged

Question 19

absorption

Answer 19

photon interacts with inner shell electrons
photon is absorbed and electron is rejected
ionization occurs

Question 20

compton scatter

Answer 20

photon interacts with outer shell electrons
photon loses energy but electron is still ejected
ionization still occurs

Question 21

coherent scatter

Answer 21

photon interacts with outer shell electrons but matter is not altered
no ionization occurs

Question 22

radiation biology

Answer 22

the study of effects of ionizing radiation on living tissue to understand the harmful effects of x-radiation

Question 23

is all ionizing radiation harmful and can cause biologic change in cells

Answer 23

YES!!!

Question 24

mechanisms of radiation injury

Answer 24

1. ionization
2. free radical formation

Question 25

direct theory

Answer 25

cell damage can occur when ionizing radiation directly hits critical areas (cell death)

Question 26

indirect theory

Answer 26

x-ray photons absorbed within cell and cause formation of toxins (causing damage indirectly)

Question 27

dose-response curve

Answer 27

used to establish acceptable levels of radiation exposure

Question 28

stochastic

Answer 28

probability of occurrence increases with dose severity is NOT dependent on does all or none

Question 29

nonstochastic/deterministic

Answer 29

severity of damage dependent on dose occur only after exceeding threshold result of severe cell damage

Question 30

radiation injury sequence

Answer 30

1. latent period 2. period of injury 3. recovery period

Question 31

determinants for radiation injury

Answer 31

total dose amount of tissue irradiated age dose rate cell sensitivity

Question 32

short-term effects

Answer 32

seen within minutes, days, or weeks large amount of radiation in short time

Question 33

long-term effects

Answer 33

appear after years, decades, or generations small amount of radiation over long period of time

Question 34

somatic effect

Answer 34

injury to person irradiated NOT passed to offspring all cells except reproductive cells

Question 35

genetic effects

Answer 35

not seen in person irradiated passed onto future generations reproductive cells effected

Question 36

radiosensitive cells

Answer 36

blood cells bone marrow reproductive cells skins lens of eyes

Question 37

radioresistant cells

Answer 37

muscle tissue nerve tissue mature bone/cartilage tissue salivary glands thyroid gland

Question 38

tradition units of measure

Answer 38

roentgen (R) radiation absorbed does (rad) roentgen equivalent (in) man (rem)

Question 39

si units of measure

Answer 39

coulombs/kilogram (C/kg) gray (Gy) sievert (Sv)

Question 40

exposure

Answer 40

roentgen or coulombs/kilograms amount of radiation in the air

Question 41

dose

Answer 41

rad or gray amount of radiation absorbed by tissue

Question 42

dose equivalent

Answer 42

rem or sievert measurement of effect on tissue

Question 43

risk elements in dentistry

Answer 43

thyroid gland bone marrow skin eyes