3.1- Medical Applications Of Physics

Question 1

What waves do X-rays as?

Answer 1

Transverse

Question 2

What are X-rays used in? (2)

Answer 2

> cancer treatment

>medicine

Question 3

How does photographic film work?

Answer 3

X-rays travel through body and hit film, apart from bone and metal

Question 4

How do CT scans work?

Answer 4

Take many images to form a 3D image

Question 5

What frequency is ultrasound more than?

Answer 5

20kHz

Question 6

How ultrasound is used

Answer 6

Some waves are reflected when a boundary between 2 different media is met, time taken can determine distance

Question 7

What detects the ultrasound waves?

Answer 7

The detector

Question 8

Uses of ultrasound (2)

Answer 8

> pre-natal scans

>removal of kidney stones

Question 9

Retina function

Answer 9

Contains light receptors which send impulses to the brain

Question 10

Lens function

Answer 10

Refracts light onto retina

Question 11

Cornea function

Answer 11

Refracts light onto lens

Question 12

Pupil/ iris function

Answer 12

Iris controls how much light enters the pupil

Question 13

Ciliary muscle function

Answer 13

Adjusts shape of lens

Question 14

Suspension ligaments function

Answer 14

Changes shape of lens

Question 15

What causes long sightedness?

Answer 15

Eyeball being too short or lens not being able to focus

Question 16

What causes short sightedness?

Answer 16

Eyeball being too long or lens not being able to focus

Question 17

What is the equivalent to a retina in a camera?

Answer 17

The CCDs

Question 18

How is the focal length of a lens determined?

Answer 18

Refractive index of material and the curvature of the two surfaces of the lens

Question 19

The greater the refractive index…

Answer 19

The flatter the lens

Question 20

What an visible light be sent along?

Answer 20

Optical fibres eg. Endoscope for internal imaging