Ultrasound
I can describe what ultrasound is and explain its properties, and also describe some uses of ultrasound.
Ultrasound
I can describe what ultrasound is and explain its properties, and also describe some uses of ultrasound.
Lesson details
Key learning points
- Sound waves of frequency below 20 Hz usually cannot be heard by humans, so are called infrasound.
- Sound waves of frequency above 20 000 Hz usually cannot be heard by humans, so are called ultrasound.
- Ultrasound waves can cause objects to vibrate, so transfer energy. They do not cause harm to the human body.
- Ultrasound can be used to image structures inside the body as it reflects from boundaries between tissues.
- Ultrasound vibrations can clean delicate objects and can help to treat injuries and illnesses in physiotherapy.
Common misconception
Ultrasound may be harmful to the human body (similar to X–rays).
Ultrasound is essentially the same thing as sound (longitudinal waves). It consists of vibrations of matter, rather than an additional entity or 'ray' that interacts strongly with matter. Compare sound of 19 999 Hz with ultrasound of 20 001 Hz.
Keywords
Sound wave - a ‘pulse’ that travels through a material, caused by forward and backward vibrations of particles
Frequency - the number of vibrations each second
Ultrasound - sound waves with a frequency above 20 000 Hz, that cannot be detected by human ears
Tissue - a group of living cells that are similar and perform a specific function
Licence
This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).
Video
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Starter quiz
6 Questions
act as levers to amplify vibrations
funnels sound into the ear canal
vibrates when a sound wave hits it
sends signals to the brain
contains liquid, and hair cells that can produce nerve signals