Chapter 04: Radiation Biology

Chapter 04: Radiation Biology

 

Complete Chapter Questions With Answers

 

Sample Questions Are Posted Below

 

MULTIPLE CHOICE

 

1. (1) All ionizing radiations cause damage to living tissues. (2) Although very little radiation is used in dentistry, damage to the cells does occur.

a.	Both statements are true.
b.	Both statements are false.
c.	The first statement is true; the second statement is false.
d.	The first statement is false; the second statement is true.

 

 

ANS:  A

All ionizing radiations are harmful and produce biologic changes in living tissue. The amount of radiation used in dental radiography is small, but biologic damage does occur. The amount of radiation used in dental radiography is small, but biologic damage does occur. All ionizing radiations are harmful and produce biologic changes in living tissue.

 

DIF:    Comprehension                               REF:   Page 31          OBJ:   1

TOP:   CDA, RHS, III.C.2. Demonstrate understanding of x-radiation biology

MSC:  NBDHE, 2.0 Obtaining and Interpreting Radiographs | NBDHE, 2.1 Principles of radiophysics and radiobiology | NBDHE, 2.2 Principles of radiologic health

 

2. What specific mechanism of radiation injury may result in the formation of hydrogen peroxide when x-ray energy is absorbed by patients?

a.	An ejected high-speed electron may interact with other atoms within absorbing tissues.
b.	Free radical formation created by the ionization of water may occur.
c.	Unequal charge distribution may result in negative electrical potential.
d.	Creation of a magnetic field may cause polarization.

 

 

ANS:  B

This is an example of ionization; hydrogen peroxide may be formed as a result of free radical formation. Free radical formation created by the ionization of water may occur. Hydrogen peroxide may be formed as a result of the recombination of free radicals created by the ionization of water.

 

DIF:    Comprehension                               REF:   Page 31          OBJ:   2

TOP:   CDA, RHS, III.C.2. Demonstrate understanding of x-radiation biology

MSC:  NBDHE, 2.0 Obtaining and Interpreting Radiographs | NBDHE, 2.1 Principles of radiophysics and radiobiology | NBDHE, 2.2 Principles of radiologic health

 

3. Which of the following statements is true regarding the direct theory of radiation injury?

a.	It involves absorption of an x-ray photon by water within a cell.
b.	It involves the formation of toxins that damage the cell.
c.	It involves damage to the critical areas of a cell through direct contact with the x-ray photon.
d.	It involves the formation of free radicals.

 

 

ANS:  C

The indirect theory of radiation injury involves absorption of an x-ray photon by water within a cell. The indirect theory of radiation injury involves the formation of toxins that damage cells. The direct theory of radiation injury involves a direct hit to and absorption of an x-ray photon within critical areas of a cell. The indirect theory of radiation injury involves the formation of free radicals.

 

DIF:    Comprehension                               REF:   Page 31          OBJ:   2

TOP:   CDA, RHS, III.C.2. Demonstrate understanding of x-radiation biology

MSC:  NBDHE, 2.0 Obtaining and Interpreting Radiographs | NBDHE, 2.1 Principles of radiophysics and radiobiology | NBDHE, 2.2 Principles of radiologic health

 

4. The indirect theory proposes that

a.	toxins are created from the formation of free radicals.
b.	ionizing radiation strikes critical areas within cells.
c.	direct injuries occur more frequently than indirect injuries.
d.	changes occur to the deoxyribonucleic acid (DNA) of a cell.

 

 

ANS:  A

The indirect theory proposes that free radicals combine to form toxins. The direct theory proposes that ionizing radiation directly hits critical areas within cells. Indirect injuries occur more frequently than direct injuries. The direct theory proposes that the deoxyribonucleic acid (DNA) of a cell is damaged during radiation exposure.

 

DIF:    Comprehension                               REF:   Page 31          OBJ:   2

TOP:   CDA, RHS, III.C.2. Demonstrate understanding of x-radiation biology

MSC:  NBDHE, 2.0 Obtaining and Interpreting Radiographs | NBDHE, 2.1 Principles of radiophysics and radiobiology | NBDHE, 2.2 Principles of radiologic health

 

5. According to the dose-response curve, when dose and damage are plotted on a graph, a _____________________ relationship is seen.

a.	nonlinear, nonthreshold
b.	linear, nonthreshold
c.	nonlinear, threshold
d.	linear, threshold

 

 

ANS:  B

When dose and damage are plotted on a graph, a linear, nonthreshold relationship is seen.

 

DIF:    Recall             REF:   Page 32          OBJ:   3

TOP:   CDA, RHS, III.C.2. Demonstrate understanding of x-radiation biology

MSC:  NBDHE, 2.0 Obtaining and Interpreting Radiographs | NBDHE, 2.1 Principles of radiophysics and radiobiology | NBDHE, 2.2 Principles of radiologic health