Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Radiology Imaging III > Chapter 7 Molecular and Cellular Radiation Biology > Flashcards

Chapter 7 Molecular and Cellular Radiation Biology Flashcards

1
Q

What is Radiation Biology?

A

branch of biology concerned with effects of ionizing radiations on living systems

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is ionizing Radiation?

A

knocking of electrons from atoms that make up molecular structures of systems

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the the two types of ionizing radiation?

A

electromagnetic radiation - electric and magnetic fields that travel through space at the speed of light
particulate radiation - particles emitted from radioactive decay

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the two types of electromagnetic radiation?

A

X-ray - 2nd most energetic type, weighting factor of 1
Gamma - most energetic type, weighting factor of 1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the two types of particulate radiation?

A

Beta - used in radiation therapy weighting factor of 1
Alpha - emitted from plutonium and uranium weighting factor of 20, greatest biologic effect internally

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is Linear Transfer Energy?

A

average energy deposited per unit length of track by ionizing radiation as it passes through and interacts with a medium along its path

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the unit of measurement for LET?

A

keV/micrometer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the low LET’s and high LETs

A

Low - Gamma and X-ray
High - alpha and beta

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Why do high LET particles lose energy quickly?

A

more ionization per unit of distance traveled

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Where are repair enzymes working at to repair radiation damage?

A

molecular level

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is Relative biological effectiveness?

A

capability of radiations with various LETs to produce a particular biologic reaction, various LETs do not render the same biologic effect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How is relative biologic effectiveness quantified

A

RBE = dose in Gy from 250-kVp X-rays/ dose in Gy of test radiation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What type of tissue is more radiosensitive?

A

oxygenated is more radiosensitive compared tohypoxic or anoxic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the oxygen enhancement ratio?

A

ratio of radiation dose required to cause particular biologic response in oxygen-deprived environment to the radiation dose required to cause identical response under normal oxygen conditions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What does high LET radiation cause?

A

biologic effect from direct action

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What does low LET radiation cause?

A

OER about 3.0 with high dose 2 Gy or more, direction action creating free radicals cause more biologic damage with greater oxygenation

17
Q

What are the three areas that repair can happen?

A

molecular, cellular, organic

18
Q

What happens when tissue has a direct action with ionizing radiation?

A

usually with high LET radiation, when ionizing radiation interacts with DNA RNA proteins or enzymes

19
Q

What is radiolysis of water?

A

radiation interacts with water molecules and free radials are produced

20
Q

What happens with indirect action of ionizing radiation?

A

free radicals produced with radiolysis/hydrolysis

21
Q

What are the different effects of ionizing radiation on DNA?

A

single string break
double strand break
chromosome effect after double strand break in same rung of DNA
mutation
covalent cross link

22
Q

What are the effects of ionizing radiation on chromosomes?

A

radiation induced chromosome breaks
chromosomal fragments
chromosomal anomalies

23
Q

What is the Target Theory?

A

concept of radiation damage resulting from discrete and random events, master or key molecule is necessary for the survival of the cell, used to explain cell death and nonfatal cell abnormalities caused by exposure to radiation

24
Q

What are the effects of irradiation on the entire cell?

A

instant death - 1000 Gy in less than a few minutes
reproductive death - 1-10 Gy, cannot procreate
apoptosis - non mitotic cell death that occurs when cells die without attempting division in interphase, caused by a few hundred cGy
mitotic death - less dose than apoptosis, cell dies after one or more divisions
mitotic delay - 0.01 Gy can cause, may or may not resume normal function

25
Q

What are the two types of cells?

A

mature and immature

26
Q

What are mature cells?

A

more specialized in function, divide at a slower rate or do not divide at all, not as sensitive to radiation, highly differentiated

27
Q

What are immature cells?

A

nonspecialized, undergo rapid cell division, more sensitive to radiation, undifferentiated, lymphocytes most sensitive

28
Q

What are oxygen enhancement effects?

A

enhanced effects of ionizing radiation, increased radiosensitivity, more free radicals are formed, high is x-ray and gamma because they are indirect

29
Q

What does radiation therapy have to do with oxygen enhancement effects?

A

high pressure O2 is used to increase radio sensitivity of some types of tumors

30
Q

What is OER?

A

ratio of radiation dose required to cause a particular biologic response

31
Q

What is the number of OER for x-ray and Gamma?

A

3

32
Q

What is the Law of Bergonie and Tribondeau

A

radiosensitivity of cells are directly proportional to their reproductive activity and inversely proportional to their degree of differentiation, most radiosensitive cells are least specialized, least mature, have greatest reproductive capability, and longest mitotic phase, originally only applied to germ cells but now true for all cells of the body

33
Q

How are blood cells effected from ionizing radiation?

A

lymphocytes most radiosensitive

34
Q

How are epithelial tissues effected from ionizing radiation?

A

body constantly regenerates, very radiosensitive including lungs intestinal lining, blood and lymphatic vessel lining

35
Q

How are muscle tissues effected from ionizing radiation?

A

highly specialized, radio resistant

36
Q

How are nervous tissue effected from ionizing radiation?

A

highly specialized in adults, radioresistant, fetus 8-15 weeks most radiosensitive

37
Q

How are reproductive cells effected from ionizing radiation?

A

germ cells are radiosensitive

38
Q

How much Gy can cause temporary sterility?

A

2 Gy

39
Q

How much Gy can cause permanent sterility?

A

5-6 Gy

Radiology Imaging III (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions