Radiation and Chemotherapy Flashcards
+ Cell injury (9 cards)
Which of the following statements regarding radiation is NOT correct?
a. Radiation is the emission and transmission of energy in the form of waves or particles through space or time.
b. Ionising radiation is capable of dislodging electrons.
c. Ionising radiation can also be used for diagnostic imaging.
d. Microwave ovens are a potent source of ionising radiation.
Answer: d
Microwave opens are NOT a potent source of ionising radiation - they emit NON-IONISING RADIATION
Which one of the following statements regarding radiation therapy is NOT correct?
a. Radiation is typically focused and targeted towards a specific area.
b. Treatment may be delivered by means of an external beam or an internal implant.
c. The treatment may generate free radicals that damage cellular components.
d. Mutations within cells that survive radiation are the result of damage to cellular organelles such as mitochondria.
Answer: d
Mutations occur due to damage to the DNA
- Ionising radiation causes double-strand break in DNA or free radical formation, which then damages DNA can lead to mutations in surviving cells.
Which one of the following statements regarding biological effects of radiation is NOT correct?
a. Hypoxia within tissues results in reduced efficacy of radiation therapy.
b. Slowly-dividing cells are more prone to the treatment than rapidly dividing cells.
c. Cells injured by radiation are eliminated by apoptosis.
d. Continuous radiation produces more injury than periodic.
Answer: b
The opposite is true - rapidly dividing cells (such as cancer cells) are more prone to the treatment.
Which one of the following statements regarding effects on tissues is NOT correct?
a. The endothelium of blood vessels is highly sensitive to radiation therapy.
b. The adult brain is resistant to radiation injury.
c. Radiation therapy treats an existing cancer and prevents future malignancy in the patient.
d. Atrophy of tissue may be a late consequence of radiation therapy.
Answer: c
Radiation does NOT prevent future malignancy in patients.
(There is a small risk of causing future malignancy)
Which one of the following statements regarding radiation is NOT correct?
a. Ionising radiation is capable of removing tightly bound electrons to form ions within tissues of the body.
b. Ionising radiation may be used to treat cancer but may also be used for diagnosis of disease.
c. Radiation is the emission of energy in the form of waves or high speed particles.
d. Production of ions requires energy of long wavelength and low frequency.
Answer: d
Ionising radiation requires high energy radiation, which means:
* SHORT wavelengths
* HIGH frequency
Which one of the following statements regarding radiation-induced cellular injury is NOT correct?
a. Radiation may result in the generation of free radicals which are capable of causing damage.
b. Radiation may directly injure cellular organelle such as mitochondria.
c. DNA may be damaged but chromosomes are not.
d. Injured cells are eliminated by apoptosis.
Answer: c
Chromosomes are made of DNA - so any damage to DNA inherently affects chromosomes.
Radiation can cause:
* Single-or-double strand DNA breaks.
* Chromosomal aberrations like deletions, translocations, or fragmentation,
* Mutations that can lead to cancer or cell death.
- (b) Radiation can directly damage organelles, although DNA is the primary target due to its radio sensitivity.
Which one of the following is NOT a determinant of the biological effects of ionising radiation?
a. During radiation treatment cell injury may be less in hypoxic tissues or enhanced by hyperbaric oxygen treatment.
b. Continuous radiation is more damaging than intermittent or periodic treatment that delivers the same total amount.
c. The larger the dose of radiation the more the tissue damage.
d. Slowly dividing cells are highly susceptible to radiation, allowing more damage to occur to them during the treatment.
Answer: d
Rapidly dividing cells are more susceptible to radiation.
Cancer cells (target) = Rapidly dividing cells
Which one of the following statements regarding effects of ionising radiation is NOT correct?
a. Serious consequence may arise is bone marrow and the lymphoid system are affected.
b. Injury to blood vessels is common.
c. Fibrosis within tissues is a common consequence.
d. Every effort should be made to protect the adult brain from injury due to its extreme sensitivity.
Answer: d
The adult brain is RESISTANT to ionising radiation.
- (b) Radiation can injure ENDOTHELIAL cells
Which one of the following statements regarding cell injury is NOT correct?
a. Energy production is impaired due to damage to the nucleus.
b. Damage to the endoplasmic reticulum affects protein synthesis.
c. Cell membranes are damaged.
d. Cells may become waterlogged.
Answer: a
“Energy production by damage to the MITOCHONDRIA” (slide 5 - Cell injury and death)
