What are X Rays used for?
To identify fractures and broken bones
What are ultrasounds used for?
To create a picture of unborn babies and to dislodge kidney stones by braking them down into small particles which can be passed through the urine.
Why aren't X Rays used to scan unborn babies?
Because X Rays are ionising which means that they could cause mutations in undeveloped cells which could lead to abnormalilties and disease.
What are CT Scanners?
CT Scanners use X Rays to scan body parts, however they, unlike ordinary X rays, can distinguish between soft and hard tissue ie. bone AND muscle
What do radiographers wear to reduce radiation exp
They wear lead aprons and stand behind lead screens, whilst staying out of the room.
How do ultrasounds work?
Ultrasound waves are directed at the body. When they meet a boundary ie. womb and fetus they reflect back and the vibrations/echoes create an image
What type of lens is used to correct long-sightedn
A converging lens
What type of lens is used to correct short-sighted
A Diverging lens
What is short-sightedness?
If you are short sighted then when you process images the image will appear in front of your retina so it is not seen.
What is long-sightedness?
If you are long sighted then the images processed in your eye land just behind your retina so they are not seen
What is the purpose of the iris?
The iris controls the size of the pupil thus controlling the intensity of the light entering the eye
What is the purpose of the Cornea?
The cornea focuses the eye
What is the purpose of the Lens?
The lens changes shape to focus light coming from different ditances. It is attatched to the ciliary muscles and the suspensory ligaments which help it contract and relax.
What is the purpose of the Retina?
The retina is where the image is formed. Light sensitivy cells send signals to the brain which can be interpreted
How do X Rays work?
X Rays are directed towards the body and pass through it to a white sheet on the other side. The rays can easily be transmitted through the soft tissue ie. muscles but are absorbed by the hard tissue ie. bones which leaves a skeleton image on the sensor