Exam 1.5: Radiation Biology, Safety, Infection Control Flashcards Preview

D2: 621 Radiology > Exam 1.5: Radiation Biology, Safety, Infection Control > Flashcards

Flashcards in Exam 1.5: Radiation Biology, Safety, Infection Control Deck (45)
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1

What are the three effects of radiation on atoms and molecules

Excitation
Ionization
Breakage of Molecular Bonds

2

What happens to an electron when it is excited by an xray photon?

It vibrates before returning to its normal state, releasing the energy stored from the impact as heat or light

3

How could radiation create an ion pair?

A high energy photon can impact an atom and eject an orbital electron creating a positive ion and a free electron....an ion pair

4

Why is molecular bond breakage the worst type of radiation damage?

It renders the molecules useless and can kill the organelle, which might lead to cell death

5

What free radicals are created via radiolysis of water?

OH* and H*esi
Can then react with water to form
HO2*
H2O2

6

Besides water, what other common biological molecules can be turned into free radicals when hit with radiation

CO2
NO2
O2

7

What is a DIRECT effect of radiation exposure?

Ionization energy is placed directly into critical molecules within the cell

8

What is the critical biomolecule?

DNA

9

What is the INDIRECT effect of radiation exposure?

The water in the cell is radiolysed creating free radicals and toxic chemicals (H2O2) that then damage critical molecules like DNA and proteins

10

What is the period between the radiation exposure and the damage incurred by indirect effects?

Latent period

11

What are some health problems caused by the accumulative effects of radiation exposure?

Cancer
Cataracts
Birth defects

12

What factors of the radiation influence the radiobiological effects of radiation exposure?

Type of Radiation
LET (Linear Energy Transfer)
Total Dose
Penetrating ability/Quality of Beam
Local area v. Entire body

13

How do Alpha particles and X-rays compare in terms of LET?

Alpha particles have a High LET
X rays have a low LET

14

What host factors influence the radiobiological effects of radiation exposure

Species
Intrinsic resistance
Type of Tissue
Rate of cell division
Somatic Tissue vs. Genetic Tissues

15

What are the worst tissue cells to get hit with radiation?

Reproductive
Bone Marrow
GI Mucosa

16

What are the "best" tissue cells to get hit with radiation?

Muscle
Nerves

17

What are 4 Deterministic Effects

Erythema and Skin Ulcers
Epilation (Hair falls out by the roots)
Cataract Formation
Sterility

18

What is the term for genetic effects of radiation

Stochastic effects

19

What are the 4 Total Body Irradiation Syndromes

CNS Syndrome
GI Syndrome
Bone Marrow Syndrome
Lethal Effects

20

Which syndrome requires a threshold of 50+ Grays?

CNS (Neurons are able to take a lot of radiation)

21

What syndrome is imparted with 10-50 Grays

GI Syndrome

No cases of survival with doses of 10+ Grays

22

How much radiation is required to acquire Bone Marrow Syndrome

2-10 Grays

23

What percent of the average americans annual radiation comes from medical x-rays?

11%

24

What percent of the average american's annual radiation comes from radon in the ground?

54%

25

How much radiation is the average american exposed to in one year (in microSieverts)

3000 uSv

26

How many microsieverts is in one Panoramic Radiograph

7 uSv

27

What are the chances of increased cancer risk from a dental x-ray?

1 in 1 Million Billion

28

What is the difference between exposure and dose?

Exposure (R) is the amount of radiation coming out of the machine

Dose is the amount of radiation that was absorbed by a unit mass of tissue

29

What do you need to multiply the dose by to get a effective dose measurement?

The quality of the beam.

Xray multiplier = 1
Neutrons = 5
Alpha Particles = 25

30

What is the MPD for the dental team for a year?

50 mSv