Unit 4 - Early & Late Radiation Effects on Organ Systems

Question 1

If a person receives radiation exposure sufficient to cause the gastrointestinal syndrome, fatality occurs primarily because of:

Answer 1

catastrophic damage to the epithelial cells that line the gastrointestinal track, resulting in the death of the exposed person within 3 to 5 days from a combination of infection, fluid loss, and electrolyte imbalance

Question 2

For persons with hematopoietic syndrome, survival time shortens as the radiation dose:

Answer 2

increases

Question 3

Some local tissues suffer immediate consequences from high radiation doses. Examples of such tissues include:

1. bone marrow
2. male and female reproductive organs
3. skin

Answer 3

1, 2, and 3

Question 4

What determines the rate or production of chromosome aberrations?

1. the total radiation dose given to a somatic cell
2. the total radiation given to a genetic cell
3. the period of time in which radiation dose was delivered

Answer 4

1, 2, and 3

Question 5

Which of the following are classified as early tissue reactions of ionizing radiation?

Answer 5

nausea, epilation, and intestinal disorders

Question 6

The hematopoietic form of acute radiation syndrome is also called the:

Answer 6

bone marrow syndrome

Question 7

Organ and tissue response to radiation exposure depends on factors such as:

1. radiosensitivity
2. reproductive characteristics
3. growth rate

Answer 7

1, 2, and 3

Question 8

A term that is synonymous with epilation is:

Answer 8

alopecia

Question 9

A single absorbed dose of 2 Gyt can cause a radiation-induced skin erythema within:

Answer 9

24 to 48 hours after irradiation

Question 10

In 1898, after sustaining severe burns attributed to radiation exposure, this Boston dentist began investigating the hazards of radiation exposure and became the first known determined advocate of radiation protection:

Answer 10

William Herbert Rollins

Question 11

The correct order of development of the male germ cell from the stem cell phase to the mature cells is:

Answer 11

spermatogonia, spermatocyte, spermatid, sperm

Question 12

Attempts have been made to measure chromosome aberrations after diagnostic x-ray imaging procedures:

Answer 12

but successful results have not been achieved in these studies

Question 13

During cardiovascular or other therapeutic interventional procedures that use high-level fluoroscopy for extended periods, the effects of ionizing radiation on the skin are:

Answer 13

significant

Question 14

Early tissue reactions are:

Answer 14

not common in diagnostic imaging

Question 15

During the major response stages of acute radiation syndrome after the prodromal stage, the period when symptoms that affect the hematopoietic, gastrointestinal, and cerebrovascular systems become visible, is called:

Answer 15

manifest illness

Question 16

Among the atomic bomb survivors, the number of leukemia victims has _____ since the late 1940s and early 1950s. However, the occurrence rates of other radiation-induced malignancies have continued to _____ since the late 1950s and early 1960s.

Answer 16

slowly declined; escalate

Question 17

To assess the magnitude and severity of late effects on the exposed population from the 1986 nuclear power station accident at Chernobyl:

Answer 17

long-term follow-up studies are necessary

Question 18

During the 1950s and 1960s, the Navajo people of Arizona and New Mexico who mined uranium for fueld for nuclear weapons and power plants developed lung cancer years after their exposure. This provides an example of which of the following?

Answer 18

late stochastic effects

Question 19

In general, laboratory experiments with mice prove that cataracts may be induced with doses of ionizing radiation as low as:

Answer 19

0.1 Gyt

Question 20

In which of the following human populations is the risk for causing a radiation-induced cancer not directly measurable?

1. all patients in diagnostic radiology subjected to a radiation dose below 0.1 Sv
2. Chernobyl radiation accident victims living in contaminated villages
3. atomic bomb survivors

Answer 20

1 only

Question 21

Existing data on radiation-induced genetic effects in humans:

Answer 21

are both contradictory and inconclusive

Question 22

When a prediction is made that the number of excess cancers rises as the natural incidence of cancer increases with advancing age in the population, the risk is considered to be:

Answer 22

relative

Question 23

What do agents such as specific chemicals, viruses, and ionizing radiation have in common?

Answer 23

they are all mutagens that may increase the frequency of mutations

Question 24

Epidemiologic studies are of significant value to radiobiologists who use the information from these studies to formulate dose-response curves for making predictions of the risk of _____ in human populations exposed to low levels of ionizing radiation.

Answer 24

cancer

Question 25

Radiation-induced abnormalities are caused by unrepaired damage to:

Answer 25

DNA molecules in the sperm or ova of an adult

Question 26

Some mutations in genetic material occur spontaneously, without a known cause. In humans, a hereditary disorder is present in approximately _____ of all live births in the United States.

Answer 26

10%

Question 27

Currently, evidence of radiation-induced hereditary effects has not been observed in persons employed in diagnostic imaging or in persons undergoing radiologic examinations. Even with this information, it is still recommended that:

1. gonadal shielding be effectively used
2. all radiation exposure be maintained as low as reasonably achievable (ALARA)
3. alternative procedures be substituted for x-ray procedures whenever diagnostic information must be obtained

Answer 27

1 and 2 only

Question 28

Raidum decays with a half-life of:

Answer 28

1622 years

Question 29

The term linear non threshold relationship implies that the biologic response to ionizing radiation is:

Answer 29

directly proportional to the dose all the way down to levels approaching zero

Question 30

Genetic mutations at the molecular level are called:

Answer 30

point mutations

Question 31

Linear:

Answer 31

when the radiation dose is doubled, the response is likewise doubled (directly proportional)

Question 32

Non-Linear:

Answer 32

responses will increase rapidly, or taper off as dose increases

Question 33

Threshold:

Answer 33

it will take a certain dose before a response will be manifest (ex: “acute radiation syndrome”), whole body must be greater than 100 rem (1 Sievert)

Question 34

Non-Threshold:

Answer 34

any dose has the potential to cause a response (ex: diagnostic x-rays)

Question 35

Cell Sensitivity from most radiosensitive to least radiosensitive:

Answer 35

1. Lymphocytes
2. Bone Marrow
3. Gonads
4. Epithelia
5. Growing Bone
6. Kidney
7. Liver
8. Thyroid
9. Muscle
10. Nerve