Chapter 3 Flashcards
(56 cards)
What is sound?
A form of energy
How does sound travel?
In waves
What does traveling sound require?
A medium (solid, liquid or gas)
Speed of sound in air
330 m/s
Speed of sound in lungs
500 m/s
Speed of sound in fat
1,450 m/s
Speed of sound in soft tissue (average)
1,540 m/s
Speed of sound in the liver
1,560 m/s
Speed of sound in blood
1,560 m/s
Speed of sound in muscles
1,600 m/s
Speed of sound in tendons
1,700 m/s
Speed of sound in bones
3,500 m/s
Sound travels _____ in solids, _____ in liquids, and _____ in gases.
- fastest
- slower
- slowest
What is ultrasound gel and it’s purpose?
Coupling gel:
removes the air from the path of ultrasound; sound can be transmitted into the tissue
Who are the 5 “ultrasound forefathers”?
Aristotle
Boethius
DaVinci
Galileo
Doppler
What did Aristotle discover?
350 BC - sound is carried to the ears by the movement of air (sound propagation)
What did Boethius discover?
524 AD - pebble theory; waves
What did DaVinci discover?
1500 AD - angle of reflection = angle of incidence
What did Galileo discover?
1638 - frequency determines pitch
What did Doppler discover?
1842 - pitch varies if source is moving
Who is the “Father of Ultrasound” and what did he discover?
Spallanzani; pulse echo location
What is audio ultrasound?
Sound that you can hear
What is color ultrasound?
Qualitative assessment of blood flow
What is spectral ultrasound?
Measurement of audio (until you hit the “freeze” button)