P7.6 - Nuclear Radiation In Medicine (Finished)

Question 1

What do high radiation doses do to cells?

Answer 1

High radiation doses kill cells completely which can cause radiation sickness if a lot of cells die at once

Question 2

How do low doses of radiation affect cells?

Answer 2

Lower doses of radiation cause minor damage without killing cells but can give rise to mutant cancer cells

Question 3

What are radioactive traces used for?

Answer 3

They are used for tracing the flow of a substance through an organ

Question 4

Why are isotopes taken into the body usually gamma, never alpha? Why do they have a short half-life?

Answer 4

So that the radiation passes out of the body without causing much ionisation. Short half-life so radioactivity in patients body quickly disappears

Question 5

How can radioactive tracers be used to diagnose blocked kidneys?

Answer 5

Before the test the patient would drink water containing a bit of the radioactive substance. Detectors are placed against each kidney. If the kidney is not blocked the radiation will spike and go down as the substance flows in and out, if not it will go up and stay up as the substance is stuck

Question 6

How can radioactive tracers be used to check if the thyroid gland is functioning?

Answer 6

iodine-123 is swallowed by a person /injected into them, it should be absorbed by the thyroid gland as normal iodine-127, however it is slightly radioactive so it can be detected to see if the thyroid gland is taking in iodine as normal

Question 7

How does radiotherapy work?

Answer 7

High doses of ionising radiation will kill all living cells, so by directing gamma rays at the right dosage to kill cancer cells but not too many normal cells, it can be cured. Radiation emitting implants can also be put in or next to tumours

Question 8

What is the disadvantage of radiotherapy?

Answer 8

A fair bit of damage is done to normal cells, making the patient feel very ill.

Question 9

Why is gamma radiation used for radiotherapy?

Answer 9

As it can penetrate deeper into the body than alpha or beta

Question 10

What does how useful a radioactive isotope is depend on?

Answer 10

• It’s half life
• The type of radiation it gives out

(Fitting to the task)

Question 11

What is perceived risk?

Answer 11

Perceived risk is how risky a person thinks something is

Question 12

You need to consider ___ when using radioactive materials

Answer 12

Benefits vs risks