Chapter 6 Flashcards

The term “apoptosis” is synonymous with:

programmed cell death

meiosis

mitosis

point mutation

Which of the following gonadal radiation doses may cause permanent sterility in a human male?

0.01 Gy

1.0 Gy

2.0 Gy

6.0 Gy

Direct action may occur after exposure to any type of radiation, but it is much more likely to happen after exposure to:

low-LET radiation such as x-rays

low-LET radiation such as gamma rays

high-LET radiation such as alpha particles

nonionizing radiation such as microwaves

If bone marrow cells have not been destroyed by exposure to ionizing radiation, they can:

become insensitive to future exposures from ionizing radiation

overpopulate and become radioresistant

remain in circulating blood indefinitely

repopulate after a period of recovery

Neutrophils play an important role in:

circulating blood through the human body

clotting blood

fighting infection

preventing hemorrhage

Which of the following means the loss or change of a nitrogenous base in the DNA chain?

Aneuploidy

Bleb

Free radical

Mutation

Which of the following illustrates the radiation sensitivity of a particular type of cell?

Epidemiologic data curve

Extrapolation curve

Dose-response curve

Survival curve

While passing through a human cell, an x-ray photon interacts with and inactivates the cell’s master molecule. What is the consequence for the cell?

Loss of all intracellular fluid

Increased pressure on the cell membrane leading to immediate rupture

Disruption of cell chemistry only

Death

_____ of the effects of x-radiation and gamma in macromolecules of living systems (in vivo) occur as a result of indirect action.

None

Very few

Some

Most

As LET increases, the ability of ionizing radiation to cause biologic effects:

also generally increases until it reaches a maximal value

decreases considerably

decreases slightly

remains constant, not increasing or decreasing

Which of the following statements is true concerning patients who receive radiation exposure from a routine radiographic procedure such as a chest x-ray?

Patients are expected to sustain appreciable damage to either the blood or the blood-forming organs as a consequence of the examination.

Patients are not expected to sustain appreciable damage to either the blood or the blood-forming organs as a consequence of the examination.

Patients are expected to sustain some damage to either the blood or the blood-forming organs as a consequence of the examination.

Patients are expected to sustain total damage to either the blood or the blood-forming organs as a consequence of the examination resulting in fatality.

Which of the following is a scavenger-type of white blood cell that fights bacteria?

Granulocytes

Lymphocytes

Neutrophils

Thrombocytes

The radiation dose required to produce mitotic death is:

less than the dose needed to produce apoptosis in slowly dividing cells or nondividing cells

more than the dose needed to produce apoptosis in slowly dividing cells or nondividing cells

the same as the dose needed to produce apoptosis in slowly dividing cells or nondividing cells

nonexistent as mitotic death cannot be produced in slowly dividing cells or nondividing cells by ionizing radiation

Which of the following groups of cells is most radiosensitive?

Lymphocytes

Adult nerve cells

Erythrocytes

Muscle cells

Which of the following groups of cells is least radiosensitive?

Adult nerve cells

Nerve cells in the embryo-fetus

Lymphocytes

Immature spermatogonia

A periodic blood count is not recommended as a method for monitoring occupational radiation exposure because:
1. biologic damage from ionizing radiation cannot be determined from a blood test
2. biologic damage has already been sustained when an irregularity is seen in the blood count
3. a traditional blood count is a relatively insensitive test that is unable to indicate exposures of less than 10 cGy (10 rads)

1 only

2 only

3 only

2 and 3 only

Based on current data, which of the following would be considered a safe radiation dose for the gonads of both males and females?

5 Gy

3 Gy

1 Gy

0 Gy

A biologic reaction is produced by 4 Gy (400 rad) of a test radiation. It takes 16 Gy (1600 rad) of 250-kVp x-rays to produce the same biologic reaction. What is the relative biologic effectiveness (RBE) of the test radiation?

2

4

8

12

Radiosensitivity of ova:

remains constant throughout the lifetime of the germ cell

varies considerably throughout the lifetime of the germ cell

varies slightly throughout the lifetime of the germ cell

is insignificant because the germ cell is not radiosensitive

One micron (mm) = _____ m.

10–6

10+6

10–3

10+3

Which of the following humans is most radiosensitive?

A mature adult

The embryo-fetus during the first trimester of pregnancy

The fetus during the third trimester of gestation

A 5-year-old child

Which of the following is (are) considered low-LET radiation(s)?
1. X-rays
2. Alpha particles
3. Gamma rays

1 only

2 only

1 and 3 only

2 and 3 only

The normal white blood cell count for an adult ranges from _____ to _____/mm3 of blood.

1000; 5000

3000; 6000

5000; 10,000

7000; 15,000

Which of the following tissues contain cells that do not divide?
1. Epithelial tissue
2. Muscle tissue
3. Nervous tissue in the adult

1 and 2 only

1 and 3 only

2 and 3 only

1, 2, and 3

OH* + OH* = __________.

H2O

HOH+

HOH–

H2O2