week eleven

Question 1

radiation characteristics

Answer 1

x ray beam quality, quantity, and intensity

Question 2

what does wavelength determine

Answer 2

energy and penetrating power

Question 3

what does shorter wave lengths mean

Answer 3

more penetrating power

Question 4

what does longer wavelengths mean

Answer 4

less penetrating power, more likely to be absorbed

Question 5

what is the kilovoltage for older machines

Answer 5

65-100 kv

Question 6

what is the kilovoltage for current machines

Answer 6

70 kv

Question 7

what is density

Answer 7

the overall darkness or blackness of an image

Question 8

what happens to the density if kv is increased

Answer 8

increased density which means darker image

Question 9

what does contrast mean

Answer 9

shades of gray

Question 10

what image provides more shades of gray

Answer 10

higher kv = low contrast image

Question 11

what is amperage

Answer 11

amount of electrons passing through cathode filament

Question 12

what increases the number of x rays

Answer 12

increase in electrons

Question 13

what are past ma

Answer 13

7ma or 15 ma

Question 14

is what current ma

Answer 14

6ma to 8 ma or fixed at 7ma

Question 15

what does ma regulate

Answer 15

the temperature of cathode filament

Question 16

what causes a darker image increase or decrease in ma

Answer 16

increase

Question 17

what is target surface distance

Answer 17

distance from source of radiation to patient’s skin

Question 18

what is target object distance

Answer 18

distance from source of radiation to tooth

Question 19

what is target receptor distance

Answer 19

distance from source of radiation to receptor

Question 20

what are the two chemical changes that occur during radiation injury

Answer 20

ionization and free radical formation

Question 21

when does free radical formation occur

Answer 21

x ray photon ionize water

Question 22

direct theory

Answer 22

ionizing radiation directly hits critical areas within the cell

Question 23

indirect theory

Answer 23

x ray photons are absrobed within cell cause formation of toxins

Question 24

stochastic

Answer 24

occurs as a direct function of dose

Question 25

nonstochastic

Answer 25

deterministic effects

Question 26

what is the sequence of radiation injury

Answer 26

latent period, period of injury, recovery period, cumulative effects

Question 27

what are the determining factors

Answer 27

total dose, dose rate, amount of tissue irradiated, cell sensitivity, age

Question 28

what tissues or organs are sensitive to radiation

Answer 28

small lymph nodes, bone marrow, reproductive cells, skin, lens of eye, oral mucosa