Ultrasound Flashcards
Recognise the features of a longitudinal wave
Wavelength
Compression
Frequency
Rarefaction
Recognise that ultrasound can be used in medicine for diagnostic purposes
- to look inside people by scanning the body
- to measure the speed of blood flow in the body
Define wavelength
The distance between corresponding points on two compressions
Define frequency
The number of waves produced in one second
Define amplitude
The maximum disturbance caused by a wave
Define compression
A region of higher pressure (loops closer together)
Define refraction
A region of lower pressure (loops further apart)
What frequencies does ultrasound have
Higher than 20 000 Hz, i.e. Above the upper threshold of the human hearing range
Recognise that ultrasound can be used in medicine for non-invasive therapeutic purposes
Breaking down kidney stones
Describe and compare the motion and arrangement of particles Longitudinal and transverse waves
In transverse waves each particle moves up and down about its normal position at right angles (90°) to the direction of the wave movement
In longitudinal waves each particles moves up and down about its normal position parallel to the direction of wave movement
Explain how ultrasound is useful in body scans
- Ultrasound waves are reflected at a boundary as they pass from one medium (or subtsance) into another. The time taken for these reflections can be used to calculate the depth of the reflecting surface. The reflected waves are usually processed to produce a visual on screen
Explain how ultrasound is used in breaking down kidney stones
It allows kidney stones in the body to be removed without the need for painful surgery. Ultrasonic waves cause the kidney stones to vibrate, making them break up and disperse. They are then passed out of the body in urine.
Explain the reasons for using ultrasound rather than X-rays for certain scans
- able to produce images or soft tissue
- does not damage living cells
What type of wave is ultrasound
Longitudinal wave
