Mosby Ch. 4- Radiation Biology

Question 1

the phase most sensitive to radiation is the ____ phase

Answer 1

M

Question 2

the phase resistant is the ____ phase

Answer 2

S

Question 3

changes seen within days or weeks may also be called ___________ or _________ effects

Answer 3

deterministic or nonstochastic

Question 4

changes seen after months or years of exposure may be called _______ effects

Answer 4

stochastic

Question 5

Onset dose for erythema to skin

Answer 5

20 Gy

Question 6

Onset dose for dry desquation to skin

Answer 6

30 Gy

Question 7

Onset dose for wet desquation to skin

Answer 7

40 Gy

Question 8

Onset dose for mild, patchy mucositis

Answer 8

30 Gy

Question 9

Onset dose for confluent mucositis

Answer 9

40 Gy

Question 10

Onset dose for esophagitis

Answer 10

25 Gy

Question 11

Onset dose for xerostomia

Answer 11

20 Gy

Question 12

Onset dose for proctitis (inflammation of the lining of the rectum)

Answer 12

30 Gy

Question 13

Onset dose for decreased sperm

Answer 13

0.25 Gy

Question 14

Onset dose for lowered blood count

Answer 14

4 Gy

Question 15

Onset dose for extensive hypoplasia

Answer 15

50 Gy

Question 16

Onset dose for gastritis

Answer 16

20 Gy

Question 17

what do prodromal symptoms include?

Answer 17

nausea, vomiting, fatigue, fever, hypotension (low blood pressure), and diarrhea.

Question 18

what are the four R’s of radiobiology?

Answer 18

repair, reoxygenation, repopulation, and redistribution or reassortment

Question 19

the immediate symptoms that appear after an acute radiation exposure are called:

a. latent symptoms
b. proportional symptoms
c. chronic symptoms
d. prodromal symptoms

Answer 19

d. prodromal symptoms

Question 20

radiation interacts with tissue (uniformly/randomly)?

Answer 20

randomly

Question 21

the fraction of cells actually progressing through cycles of division is known as the (growth/surviving) fraction.

Answer 21

growth

during division, a portion of the cells are dividing causing growth of the tumor and another portion is dormant. the portion of cells dividing is known as the growth fraction

Question 22

the period over which radiation is delivered is referred to as the (protraction/fractionation).

Answer 22

protraction

Question 23

epilation may initially be observed in patients receiving radiation under standard fractionation schemes at an approximate dose of:

a. 30 Gy
b. 50 Gy
c. 15 Gy
d. 5 Gy

Answer 23

c. 15 Gy

Question 24

in linear or nonlinear threshold dose-response curves, the following is true of the response:

a. response will occur at all doses
b. response may not occur at low doses
c. response will never be realized
d. response is proportional to dose

Answer 24

b. response may not occur at low doses

threshold dose-response curves indicate that there is no overt response by exposed tissue below certain doses

Question 25

the most radiosensitive tissue group among the following is the: a. CNS b. alimentary tract c. muscle d. cardiovascular system

Answer 25

b. alimentary tract compared to the others, the epithelial cells in the alimentary tract have a longer mitotic future and divide more often that mature central nervous and connective tissues found in muscle and cardiovascular systems

Question 26

the whole body syndrome most likely to be observed following a single dose of 1-10 Gy is the: a. lethal dose syndrome b. CNS syndrome c. hematopoietic syndrome d. gastrointestinal syndrome

Answer 26

c. hematopoietic syndrome

Question 27

the central nervous system syndrome may be observed in those exposed to single whole body dose of: a. 300 cGy b. 5000 cGy c. 500 Gy d. 10 Gy

Answer 27

b. 5000 cGy

Question 28

normal tissue healing following radiation occurs by: a. regeneration b. repair c. revitalization d. a and b

Answer 28

d. a and b

Question 29

irradiation of the salivary glands may lead to permanent xerostomia above doses of ____ using typical 2 Gy per treatment, 5 treatments per week fractionation scheme. a. 10 Gy b. 20 Gy c. 30 Gy d. 40 Gy

Answer 29

d. 40 Gy

Question 30

the TD 5/5 for the colon is (higher, lower) than the TD 50/5.

Answer 30

lower

Question 31

regarding non-stochastic effects: 1. the effects are never in the one exposed 2. the effects are never seen in future generations 3. the probability of occurring is related to dose 4. the severity of effects is related to dose a. 1 b. 2 c. 3 d. 2, 4 e. 1, 2, 3, 4

Answer 31

d. 2, 4 non-stochastic is deterministic and manifest early in the individual exposed. the effects increase in severity as dose increases

Question 32

the part of the cell between the membrane and the nucleus is known as the: a. plasma membrane b. cytoplasm c. cytoplasmic membrane d. golgi apparatus

Answer 32

b. cytoplasm the cell has an outer membrane and central nucleus. the section between the two is the cytoplasm

Question 33

the occupational dose limit for deterministic effects to the lens of the eye is lower than the limit for the skin because: a. the lens has a greater sensitivity to radiation than the skin b. the skin has a greater sensitivity to radiation than the lens c. the lens is easier to protect from radiation than the skin d. the skin cells are more differentiated than the lens cells

Answer 33

a. the lens has a greater sensitivity to radiation than the skin

Question 34

a grade 3 morbidity score for the colon would indicate: a. diarrhea requiring parental support b. ulceration or perforation c. obstruction d. change in frequency or bowel habits

Answer 34

a. diarrhea requiring parental support

Question 35

the onset dose for wet desquamation during stand fractionation is: a. 15 Gy b. 20 Gy c. 30 Gy d. 40 Gy

Answer 35

d. 40 Gy

Question 36

somatic effects are: a. the effects limited to the exposed individual b. the effects manifested in subsequent generations c. the effects seen after large doses only d. the effects seen after small doses only

Answer 36

a. the effects limited to the exposed individual

Question 37

conventional fractionation was based on experiments performed to: a. induce tumors in mice b. eradicate tumors in mice c. sterilize rams d. produce skin reactions in rams

Answer 37

c. sterilize rams

Question 38

the standard proposed units for "rets" in Ellis' formula held the value of: a. 1800 b. 4500 c. 1600 d. 1000

Answer 38

a. 1800

Question 39

at doses above ____ Gy, you may see latent stricture in the esophagus during standard fractionation. a. 5 b. 10 c. 40 d. 60

Answer 39

d. 60

Question 40

a cell survival curve: a. usually has a shoulder and straight portion b. cannot be drawn for human cells c. cannot show the effects of dose rate d. usually shows the fraction of surviving cells on a linear scale

Answer 40

a. usually has a shoulder and straight portion

Question 41

which dose effect curve implies that if radiation dose is doubled, the biologic effect will be doubled? a. sigmoidal b. linear quadratic c. quadratic d. linear

Answer 41

d. linear a linear curve will show the changes in factors proportional