Topic 2- X-rays and ECGs

Question 1

KE=

Answer 1

e (electronic charge) x V (voltage)

Question 2

describe thermionic emission

Answer 2

hot filament (cathode) releases electrons and the anode is a metal target, x-rays are emitted by the anode

Question 3

I (current)=

Answer 3

N (number of particles per second) X q (charge on each particle)

Question 4

x-rays can harm the body through

Answer 4

ionisation

Question 5

x rays have a very high frequency and therefore

Answer 5

high energy

Question 6

x rays have enough energy to ionise molecules in

Answer 6

living cells

Question 7

intensity of radiation depends on distance from source so

Answer 7

if you move twice as far away, 1/2 squared = 1/4

Question 8

thickness of materials affects

Answer 8

x-ray absorption

Question 9

the more dense,

Answer 9

the more radiation is absorbs

Question 10

used to reduce people’s exposure to x-rays

Answer 10

lead and concrete

Question 11

x ray tube casing is used

Answer 11

to absorb x-rays

Question 12

the thicker the material,

Answer 12

the greater the reduction of x-ray intensity passing through to other side

Question 13

fluoroscopes use X-rays to create

Answer 13

moving images of a patient’s insides

Question 14

fluoroscopy is used to diagnose problems with

Answer 14

the ways organs are functioning

Question 15

CAT scans produce images of a

Answer 15

2D slice through the body

Question 16

describe CAT scan

Answer 16

X-ray beam rotates around the body and is picked up by thousands of detectors, computer works out how many x-rays are absorbed and creates image. can also make 3D image by layering

Question 17

CAT scans are often used to look for

Answer 17

tumours and cancer

Question 18

x-rays for imaging are often used because

Answer 18

the benefits outweigh the risks

Question 19

muscles cells can generate

Answer 19

potential differences

Question 20

resting potential of a muscle cell is about

Answer 20

-70 mV

Question 21

action potential is about

Answer 21

40mV

Question 22

Electrocardiographs measure the

Answer 22

action potentials of the heart

Question 23

frequency=

Answer 23

1/time period

Question 24

a pacemaker is a device used to

Answer 24

regulate heart beat

Question 25

pulse oximeters use light to check

Answer 25

the % of oxygen in the blood

Question 26

blood rich in oxgen is

Answer 26

bright red

Question 27

how the pulse oximeter works

Answer 27

transmits 2 steaks of red and infrared light and detects them at other side