Rad Protection Chapter 6-9

Front 1

Visible effects of radiation are due to?

Back 1

Cellular damage to millions of cells

Front 2

Radiation Biology?

Back 2

Branch of Biology concerned with effects of Ionizing radiations on living systems.

Front 3

Probability of radiation effects

Back 3

We can predict overall effect but Can't predict individual events "Which DNA sequence will be struck by radiation"

Front 4

Two types of Radiation interactions on cells?

Back 4

Ionizing Or Excitation

Front 5

3 different types of biological damage radiation has

Back 5

Molecular - impairs cellular function

Cellular - Damage to cells

Organic - cellular damage effects that lead to somatic and genetic damage, Organism as a whole

• Ex. Cataracts, leukemia, genetic mutations

Front 6

What is Direct Action?

Back 6

Biologic damage occurs when ionization of atoms of DNA

Occurs at High LET radiation "Higher dose"

Damage directly to DNA " absorption of energy " through photoelectric or compton

Front 7

Latent Period

Back 7

Biologic changes happen only after latent period which is when there is no evidence of damage.

Front 8

Name the 3 Radiation Energy Transfer Determinants

Back 8

What determines how much energy is transferred to the tissues ?

LET - linear Energy Transfer

RBE - Relative Biologic Effectiveness

OER - Oxygen Enhancement Ratio

Front 9

What is LET

Back 9

The rate of average energy deposited per unit of length of track " Absorbed Dose"

Front 10

Low let ?

Back 10

Gamma and x-rays , "Short wavelength"

Highly penetrating Radiation interacts randomly along it's track

Front 11

High let

Back 11

Particles, Less Penetration, More ionizing

•Alpha particles

•ions

•heavy nuclei

Charge particles that are released from interactions between neutrons and atoms

Stopped sooner energy transferred to tissues

Front 12

LET for a alpha particle is what?

Back 12

1000 times more than an electron. When the alpha particle interacts it loses energy and slows down in cell, stops in cell

Front 13

RBE?

Back 13

RBE is a comparison of a dose of Test Radiation to a dose of 250 kVp x-rays which produce the same biologic response

Killing a tumor

* RBE = dose or Gy from 250 kVp ÷ dose of Gy from test radiation *

Front 14

RBE's constant ? And measures what?

Back 14

Biologic response is the constant

RBE meausres the biologic effectiveness of radiation having different LETs

How effective was it at killing a tumor

Front 15

Low LET radiations have what?

Back 15

Low RBE, Diagnostic RBE's are

1" x-rays "

Front 16

4 factors that influence RBE?

Back 16

• Radiation type ( LET )

• Cell or tissue type ( some are more sensitive)

• Physiologic condition ( were cells already damaged )

• Radiation dose rate ( how much )

Front 17

Oxygen Enhancement Ratio " OER"

Back 17

A ratio of Radiation dose that causes a biologic response of cells with no oxygen to the same response under normal oxygen conditions

Tumors have no oxygen "harder to kill"

Front 18

OER equation

Back 18

Radiation dose response without oxygen ÷ Radiation dose response with oxygen

Front 19

Oxygen is needed for ?

Back 19

Free radicals to form during Ionization of Water "Radiolysis of Water"

80% water in body

Without free radicals, *hydrogen peroxide* is NOT formed, less cell damage

Front 20

Indirect Damage?

Back 20

Radiation hits a water molecule in the body, when molecule breaks down " free radicals ---> hydrogen peroxide is formed "

•Hydrogen peroxide causes the indirect Damage to DNA

Free radicals are produced by radiolysis of water which interact with DNA. Damage to DNA is Indirect Action

Indirect Damage is the breakdown of water molecules that produce ions and free radicals

Front 21

Free Radicals?

Back 21

Uncharged molecules ( NOT IONS )

• contain a single unpaired electron in valence shell

•They move energy to other molecules and interfere with bonds.

They take energy from cells to satisfy themselves

Front 22

Radiolysis of water?

Back 22

Human body is 80% water

Radiation of water causes indirect effects

When water is irradiated it separates into other molecules

Front 23

Chromosome Breakage

Back 23

A potential outcome when Ionizing radiation interacts with a DNA macromolecule

Front 24

After a chromosome breaks two or more chromosomal fragments what 3 things can occur?

Back 24

1. Rejoin of fragments to original config

2. Fail to rejoin and create an aberration

3. Rejoin to other broken ends, create new chromosome that "may not look structural altered"

Front 25

When and what are chromosome aberrations?

Back 25

G1 "Two daughter cells" will show break and be visible at mitosis ( Both strands )

Front 26

When do Chromatid Aberrations occur?

Back 26

G2 phase after synthesis , "only one daughter cell " will show damage

Front 27

What is Target theory ?

Back 27

DNA is the critical target.

Hits master molecule cell dies

Front 28

When a target is radiated ?

Back 28

It is considered a hit " regardless of direct or indirect "

Radiation is random in nature

Front 29

Cellular effects of irradiation ? Name 7

Back 29

Front 30

Instant death?

Back 30

Won't see in diagnostic

Nuclear accidents, cell dies

Front 31

Reproductive death?

Back 31

Will function but won't replicate

Front 32

Apoptosis

Back 32

Cells die without attempting division during the interphase portion of the cell life cycle

Dose depends on tissue radiated

Front 33

Mitotic death ?

Back 33

Cells dies after one or more Divisions

Small dose of radiation

Front 34

Mitotic Delay?

Back 34

.01Gy of Ionizing radiation just before it begins to divide . Will fail to divide on time

Front 35

What is Interference of Function?

Back 35

Front 36

Cells Radiosensitivetys?

Back 36

Radiosensitive - Immature cells -

non specialized, rapid cell division, reproduces more

Radioinsensitive - Mature cells

highly specialized "differentiated"

divide at Slow rate or not at all

Front 37

Oxygen plays a role in ?

Back 37

Radiosensitivety "more oxygen = more Radiosensitivety"

Front 38

Law of Bergonie and Tribondeau?

Back 38

Front 39

Blood cells Radiosensitivety?

Back 39

Whole body dose of .25Gy can produce measurable hematologic depressions in days

Front 40

Lymphocytes Radiosensitivety

Back 40

Most radio sensitive of all blood cells

always reproducing

Help with chronic infection

Front 41

Neutrophils Radiosensitivety?

Back 41

Help with accute infections

Front 42

Thrombocytes Radiosensitivety?

Back 42

Keep bleeding without thrombocytes

Front 43

Epithelial Tissue Radiosensitivety?

Back 43

Small bowel most Radiosensitive in GI tract

Front 44

Muscle Tissue Radiosensitivety

Back 44

Highly Radio Resistant

Highly specialized , Do not divide

Front 45

Nervous tissue Radiosensitivety?

Back 45

Front 46

Reproductive cells Radiosensitivety?

Back 46

Front 47

4 Somatic and genetic damage factors?

Back 47

Front 48

Somatic effects?

Back 48

Front 49

Early Deterministic Somatic Effects?

Back 49

Front 50

Somatic vs Genetic Effects

Back 50

Front 51

Lethal Dose ( LD ) Whole Body Exposure

Back 51

Front 52

What is the lethal dose to humans with and without medical treatment? LD 50/30

Back 52

3 to 4 Gy without treatment

8.5 Gy with treatment

Front 53

Acute Radiation Syndrome " ARS " 4 stages?

Back 53

A whole body dose all at once

Front 54

Prodromal is part of ARS and means what?

Back 54

Front 55

Latent period?

Back 55

Front 56

Manifest illness?

Back 56

Front 57

Hematopoietic syndrome?

Back 57

Whole body "bone marrow syndrome"

Front 58

Gastrointestinal syndrome?

Back 58

Small bowel most sensitive

Front 59

Cerebrovascular Syndrome?

Back 59

Front 60

Late effects of radiation?

Back 60

Cataracts, leukemia, genetic mutations

Front 61

Rats are radiated at (250kVp)

3Gy are required to cause death ( constant) is the response "Death"

Back 61

If the rats are irradiated with heavy nuclei only 1Gy would be necessary

3/1 = 3 ( the heavy nuclei is more Ionizing by 3 times ) RBE = 3

Front 62

H2O + Radiation =

Back 62

HOH+ + e-

• (knocks off a electron from water molecule)

•Electron will come back to water molecule and form water again

Front 63

H2O + e- =

Back 63

HOH - (ion)

A free electron combines with a water molecule

Front 64

Radiolysis of Water

Back 64

HOH - and HOH+ are unstable and could break apart from ?

HOH+ becomes a hydrogen ion H+ and a hydroxyl radical OH*

HOH- becomes a hydroxyl ion OH- and a hydrogen radical H*

Front 65

Ion has what? Radical has what?

Back 65

Ion + or -

Radical *

Front 66

Damage to tissues occur from what?

Back 66

Hydrogen and hydroxyl - free radicals "higher energy, ready to break bonds"

Front 67

OH* + OH* =

Back 67

Hydrogen peroxide H2O2 = damage cells

DNA

Front 68

H* + O2 = HO2* what is the radical named?

Back 68

Hydroperoxyl radical ( damaging to cell )DNA

Front 69

Direct and Indirect damage?

Back 69

They're the same damaging

Radiolysis is indirect

Front 70

Effects of Ionizing Radiation on DNA?

Back 70

Point mutation - when radiation breaks sugar phosphate change of DNA "causes late effects "

Happens at Low Let

Repair enzymes - body repairs it's self

Front 71

Double strand vs single strand break?

Back 71

Double is worse " sugar phosphate chain "

Front 72

What phase can changes be seen?

Back 72

Metaphase

Front 73

Chromosome Aberrations vs Chromatid Aberrations

Back 73

Chromosome aberrations - happens early in interphase " G1 phase"

Chromatid Aberrations - happen later in interphase " after synthesis "

Front 74

Radiosensitive cells vs radio resistent cells

Which are radioresistent?

Back 74

Muscle, nerve, Brain cells

Front 75

Deterministic vs stochastic

Back 75

Deterministic Somatic effects - higher doses directly related to cell damage

Stochastic Somatic effects - higher dose probability of cancer are higher but effects are not directly related

Front 76

Curves are either ?

Back 76

Linear or non linear

Threshold or non-threshold

Front 77

Linear vs non linear

Back 77

Linear - doubling dose doubles response

Front 78

Linear qudratic

Back 78

What we should use in diagnostic because it is more accurate but we don't

Front 79

Sigmoid

Back 79

Used in radiation therapy

Doubling dose doesn't double response

Front 80

Threshold vs non threshold

Back 80

Non threshold used in x-ray

Front 81

Stochastic ( probablistic ) graph

Back 81

All or nothing response, either get cancer or don't, chance of response

Front 82

Deterministic graph ?

Back 82

Higher doses

Front 83

Deterministic vs stochastic

Back 83

Front 84

Somatic and Genetic damage factors

Back 84

Front 85

Late Deterministic Somatic effects

Back 85

Cataracts

Front 86

Carcinogenesis

Back 86

Stochastic "probablistic" effect

Front 87

Cataractogenesis

Back 87

Single dose - 2Gy

Threshold non - linear

Front 88

Radium watch dial painters

Back 88

Front 89

Uranium Miners

Back 89

Front 90

Early medical radiation workers

Back 90

Front 91

Infants treated for thymus enlargement

Back 91

Thymus enlargement treated and caused throid cancer

Front 92

Japanese atomic bomb survivors

Back 92

Front 93

Embryologic effects

Back 93

Front 94

Genetic effects

Back 94

Front 95

List the 6 properties of the cell

Back 95

Assimilation - absorption of nutrients

Growth

Motility - movement

Secretion - movement of a substance

Irritability - respond to changes

Reproduction - reproduce

Front 96

Building blocks of an organism

Back 96

•Cells are the basic unit of structure and function

Tissues , organs, systems, Organism

Front 97

Define radiation biology

Back 97

Branch of biology concerned with the effects of Ionizing radiations on living systems

Front 98

Osmosis?

Back 98

Diffusion of a solvent through a semipermeable membrane separating solutions of different concentrations

Front 99

Endoplasmic Reticulum?

Back 99

Acts as a transport system, mRNA travels from nucleus to different locations within cytoplasm

Front 100

Golgi Apparatus

Back 100

The cells UPS " packages molecules and transports them through cell membrane so they can exit the cell

Front 101

Mitochondria

Back 101

Powerhouse of cell, ATP formed here

Front 102

Lysosomes

Back 102

Garbage bags, assist in digesting old cell parts, dead cells and bacteria

Front 103

Ribosomes

Back 103

Synthesis protein

Front 104

Centrosomes

Back 104

Formation of mitotic spindle

Front 105

Nucleus

Back 105

Heart of cell, contains DNA

Front 106

Nucleolus

Back 106

Makes and holds large part of RNA and protein

Front 107

Inorganic vs organic substances

Back 107

Inorganic - compounds that do not contain carbon ( salts, water, sodium, potassium )

Organic - compounds which all have carbon, ( proteins, lipids, carbs, nucleic acids )

Front 108

Proteins

Back 108

Elementry Building block

15% of cell

Makes new tissue

Front 109

Lipids

Back 109

2% of cell

Stores energy

Insulation

Lubricate joints

Front 110

Carbs

Back 110

1% of cells

Front 111

Nucleic acids

Back 111

1% of cells

DNA and RNA

Blueprint for reproduction of cell

Front 112

DNA structure

Back 112

•Two long sugar phosphate chains

•Double helix config

•made of nucleotides

•nitrogen base made of

Purines

Adenine (A) and Guanine (G)

Pyrimidines

Cytosine (C) and Thymine (T)

Front 113

How does DNA function in the cell

Back 113

DNA regulates cellular activity indirectly by transmitting genetic info outside nucleus by reproducing itself in the form of messenger RNA

mRNA makes proteins out of amino acids

Front 114

Mitosis vs Meiosis

Back 114

Mitosis - somatic cells, parent divides to form 2 daughter cells identical to parent

Meiosis - Germ cells, reduces number of chromosomes in each daughter cell to have as parent

Front 115

Interphase

Back 115

Cell prepares to divide ( subdivied into G1, S and G2, DNA replication occurs )

Front 116

Prophase

Back 116

Centriole divide , spindle fibers formed , DNA begins to take form

Front 117

Metaphase

Back 117

Paired chromosomes line up at equator of cell, membrane disappears

Front 118

Anaphase

Back 118

Centromeres divide, sister chromatids detach

Front 119

Telephase

Back 119

DNA unravels to form chromatin, daughter cells are formed

Front 120

Mitosis in order

Back 120

Front 121

Discuss HGP

Back 121

To discover all DNA in chromosomes in Humans

Front 122

Discuss goals of HGP

Back 122

Front 123

Discuss scientific and ethical implications of HGP

Back 123

Privacy and fairness

Ethical issues of knowing conditions

Front 124

Low let radiations have ?

Back 124

Low RBE

Front 125

Period of cell growth before cell division

Back 125

Interphase

Front 126

Segments of DNA that serve as units of hereditary

Back 126

Genes

Front 127

Organic compounds have what?

Back 127

Carbon

Front 128

Protein molecules made by specialized cells in bone marrow, called B lymphocytes

Back 128

Antibodies

Front 129

Compounds called pyrimidines

Back 129

Cytosine and Thymine

Front 130

Compounds called purines

Back 130

Adenine and Guanine

Front 131

Proper cell Function depends on enzymes?

Back 131

True

Front 132

Lipids are organic

Back 132

True

Front 133

Lymphocytes made where in human body?

Back 133

Bone marrow

Front 134

Back 134

36 ÷ 6 = 6Gy RBE = 6

Front 135

LET is an important factor for ?

Back 135

Assessing potential tissue and organ damage from Ionizing Radiation

Front 136

Abnormal decrease in white blood corpuscles

Back 136

Leukopenia

Front 137

Alopecia

Back 137

Epilation "hair loss"

Front 138

Chromosomal damage can occur from low or high let ?

Back 138

True

Front 139

Another name for stochastic Somatic

Back 139

Probablistic

Front 140

A safe dose of radiation to gonads ?

Back 140

0

Front 141

Radiolysis of water happens at low or high let typically?

Back 141

Low, Diagnostic Ranges "x-ray"

Front 142

ARS means what?

Back 142

Acute Radiation Syndrome

Front 143

In utero

Back 143

Highly Radiosensitive due to reproduction of cells

Front 144

Carcinogenesis is what

Back 144

A late stochastic effect

Front 145

LET is directly related to RBE?

Back 145

True