Chpt.3: *Ultrasound

Question 1

The negative pressure is called? (sound wave)

Answer 1

Rarefraction (pushing back from water)

Question 2

What are the 2 modes of waves called?

Answer 2

• Longitudinal (occur mostly in liquids)

- shear wave (occur mostly in solids)

Question 3

What is the relationship between absorption and penetration is?

Answer 3

Inverse relationship

Question 4

If the U.S. head is not moved, a ______wave could form?

Answer 4

Standing wave or Stationary wave

*tissue cells burning occurs

Question 5

The range of therapeutic US in frequency is from __ MHZ to ___MHZ?

Answer 5

1-3 MHZ

Question 6

Intensity (total power/sound) is measured in __ /cm2?

Answer 6

watts

Question 7

**What is Cavitation?

Answer 7

The expansion and contraction of a molecule of air (gas bubble= expansion and contraction)

Question 8

What are the settings most likely to decrease swelling?

Answer 8

very low intensity (ex. 1 mhz)

Question 9

**How does U.S. act “non thermally”? (3)

Answer 9

1. accoustic streaming,
2. cavitation
3. cell membrane effects (can’t live without ions)

Question 10

What is the purpose of gel in US?

Answer 10

• Decreases resistance
• prevents a standing wave
• improves penetration

Question 11

What is the frequency for superficial US?

Answer 11

3 MHZ

Superficial=High

Question 12

What is a likely power for heating?

Answer 12

high power

Question 13

What is an example of non-ionizing radiation?

Answer 13

Anything under ultraviolet B:

• infrared radiation
• invisible light
• radio,
• microwave,
• ultraviolet A,

Question 14

Ionizing means:

Answer 14

there is enough energy inside of a photon to rip off /discharge an electron (an atom has lost an electron)= A FREE RADICAL – can lead to DNA Damage!!!

Question 15

*What is a photon?

Answer 15

A particle of light that has NO MASS and NO CHARGE, but contains energy; nobody has ever seen one
-(they can affect change)

Question 16

What is the type of radiation that can “tan” the skin?

Answer 16

Ultraviolet B

Question 17

What are (3) types of radiation from the sun?

Answer 17

• Visible light (red/orange/yellow),
• ultraviolet,
• infrared light,
• microwave light,
• radio light,
• X-rays,
• gamma waves

Question 18

Which hormone regulates sleep cycle and has a major role in immunity?

Answer 18

Melatonin

Question 19

Aristotle detected that objects can be detected at a distance through amplification, and therefore water is an excellent ____ for sound

Answer 19

mediator

Question 20

What is the positive pressure called? (sound wave)

Answer 20

Compression (pushing against wave)

Question 21

**Describe how an Ultrasound works?

Answer 21

When using an ultrasound machine, a crystal in the head EXPANDS and CONTRACTS which causes the molecules in the tissue below to COMPRESS and DECOMPRESS.

(-When energy hits crystal, it goes the same direction, not into all different directions!!!)

Question 22

What does the Frequency of U.S. represent?

Answer 22

Depth of penedtraion

Question 23

high Frequency=

Low Frequency=

Answer 23

• Superficial

- Deep

Question 24

What is the relative resistance of the medium to the Wave energy?

Answer 24

ACCOUSTIC resistance

Question 25

Why is bone easily targeted with ultrasound ?

Answer 25

because it has high ABSORPTIVE properties

Question 26

Why do we not want to refraction?

Answer 26

waves of the frequency add up, and therefore shatter the crystals and it overheats, and therefore also burns patient

Question 27

What is frequency

Answer 27

number of cycles per second

Question 28

The therapeutic US is in which range?

Answer 28

0.75- 3MHZ

Question 29

The frequency of ultrasound determines what?

Answer 29

the amount of absorption of energy in tissues

Question 30

How are waves transferred onto patients skin?

Answer 30

the metal head; it transmits waves from the crystal to the tissue

Question 31

What does the Spatial peak Intensity refer to?

Answer 31

maximum intensity appearing at any point in the beam

Question 32

You cannot effectively radiate more than how many more times than the U.S. head?

Answer 32

2 times

Question 33

What happens with unstable cavitation?

Answer 33

production of small vapor-containing bubbles or cavities in a liquid or tissue by ultrasound

Question 34

Periosteum, scar tissue, and capsules all retain more heat than fat/blood because?

Answer 34

dense tissue retains more heat

Question 35

What is accoustic streaming?

Answer 35

movement of gas bubles

Question 36

How is there improved healing of muscle due to U.S.?

Answer 36

-protein synthesis-> collagen is produced, which speeds up tissue healing

Question 37

What are some other effects of U.S. Non-thermally? (3)

Answer 37

1. Protein synthesis 2. Angiogenesis (beginning more blood to area) 3. Wound contraction

Question 38

What are some contraindications for Ultrasound?

Answer 38

1. On/near CANCER 2. Low back or abdomen of a pregnant female 3. Eyes and gonads 4. Over pacemakers 5. Compromised sensation prior to heating

Question 39

What are the standard times for treatment heating tissue?

Answer 39

15 min.