02 - Respiratory II & III Flashcards
Air Pressure Chest Wall Shape and Movements
Volume is one way of measuring respiratory function. What are 3 other things we can measure?
Air Pressure
Airflow
Chest wall shape and movement
What is respiratory air pressure, and what units is it measured in?
The forces generated by the respiratory process
-includes speech pressures (Palv, Ps, Ptrach, Poral, Pnasal)
Measured in cmH2O (centimeters of water)
Air Pressure reflects the _____ for speech
Power Supply
What is Palv?
Alveolar pressure - the pressure inside the lungs
What is Ps?
Subglottal pressure - the pressure below the vocal folds
What is Ptrach?
Tracheal pressure - the pressure below the vocal folds and inside the trachea
What is Poral?
Oral pressure - the pressure inside the mouth
What is Pnasal?
Nasal pressure - the pressure inside the nasal cavities
When are the oral, subglottal, tracheal, and alveolar pressures all equal (i.e. what conditions must be met)?
When:
- the nose is plugged or velum elevated
- the vocal folds are open
- the mouth is closed
What is one device that can be used to measure pressure?
Manometer (u-tube or pressure gauge)
Air Pressure Transducer
What is the manometer useful for, and what is it not suitable for?
Useful for slow, continuous (static) pressures, like determining if a patient can hold a given pressure for a length of time
Not suitable for measuring most rapid dynamic speech pressures
In patients with neurological damage, what rule has been found useful for estimating their ability to demonstrate the minimal air pressure requirements for speech?
The ‘5cmH2O for 5 seconds” rule
Can also be completed using a straw in a glass
When using a(n) _______, pressure creates a continuous electrical signal for display on an oscilloscope or computer
Air Pressure Transducer
Which device for pressure measurement involves a tube being placed on the end of the device and inserted into the mouth?
Air Pressure Transducer
Which device uses a u-tube or pressure gauge?
Manometer
Pressure obtained during /p/ in continuous speech provides an estimate of what pressure?
Speech Subglottal Pressures
What is the range of pressure (in cmH2O) necessary for conversational speech?
5-10 cmH2O
Air pressure and speech loudness are ______ (proportional/inversely proportional
Proportional - pressure increases fairly consistently with speech loudness (e.g. double air pressure and see 8-9 dB increase in loudness)
When loudness is kept constant, the intraoral (subglottal) pressure _______ (remains consistent, is elevated, decreases)
Remains consistent
Put the following populations in order, from lowest to highest, for average maximum effort air pressures:
children, young males, older females, older males, young females
Children: 35-50 cmH2O Older Female: 87 cmH2O Young Female: 121 cmH2O Older Male: 123 cmH2O Young Male: 166 cmH2O
What is the average maximum effort air pressure that young males are capable of?
166 cmH2O
What speech sounds have the highest intraoral air pressure:
voiced plosives, voiceless plosives, voiced fricatives, voiceless fricatives, glides/liquids, or nasals?
Voiceless plosives: 5-7 cmH2O
What speech sounds have the lowest intraoral air pressure:
voiced plosives, voiceless plosives, voiced fricatives, voiceless fricatives, glides/liquids, or nasals?
Nasals: 0.2 - 0.4
What is airflow? What are its units?
Change in volume of air over a certain period of time (also referred to as “volume velocity”
ml/sec (also ml/min & l/sec)
Name one of the two devices used to measure airflow
Rotameter
Pneumotachograph
Describe how a rotameter works
The amount of airflow blown into the base of the tube causes the ball inside to rise to different calibrated heights
What is a rotameter used to measure?
Continuous static airflow (NOT rapid dynamic airflows found in continuous speech)
Describe how a pneumotachograph works
It is an air flow transducer which provides a continuous electrical signal for oscilloscopic display or a computer, and is based on a change in pressure across a constant resistance
-a pressure transducer is located on either side of a face mask, with a small wire mesh of a known resistance to flow
Flow = (pressure 1 - pressure 2)/resistance
Average air flow during conversation is largely related to the air flow during _______ (consonants/vowels)
Vowels
adult average air flow in conversation= 160-170 ml/sec
What is the average air flow during a prolonged /a/ for men? Are women higher or lower?
112 ml/sec (women are lower at 94 ml/sec)
What type of consonants produce the highest air flows, and what is the value?
Voiceless stops /ptk/ = 900 ml/sec
What type of consonants produce the lowest air flows, and what is the value?
Glides/Liquids = 100-150
What measures are used to estimate laryngeal resistance?
Oral air pressure and oral air flow
What is the formula for resistance?
Resistance = Pressure / flow
Ohm’s Law
If we measured peak air pressure of /p/ and airflow during /i/ to find values of 5 cmH2O and 140 ml/sec, what would our laryngeal resistance be?
Resistance = pressure/flow Resistance = 5 cm H2O / 0.14 L/sec Resistance = 35.7 cmH2O/L/sec
Average normal adult laryngeal resistance = 35 cmH2O/L/sec
Do breathy voices have a higher or lower laryngeal resistance?
Lower (20)
Airflow = 250 mL/sec (as opposed to 170 ml/sec), so larger denominator = smaller resistance value
(Resistance = pressure/flow)
Do strained voices have a higher or lower laryngeal resistance?
Higher (60)
Airflow = 83 mL/sec (as opposed to 170 ml/sec), so smaller denominator = larger resistance value
(Resistance = pressure/flow)
Lung volume changes are related to the movements of which 2 components of the chest wall?
Rib cage movements
Abdomen movements
Measurements of the changes in diameter of the rib cage and abdomen during breathing will accurately measure changes in _______
Total lung volume
Name one way that we can measure RC (rib cage) and ABD (abdomen) movements
Inductive Plethysmography
Respitrace Instrument
- 2 coiled wires wrap around RC and ABD
- diameter changes of the coiled wires cause changes in the inductance (electromagnetic levels)
RC and ABD is continuously obtained as an electrical signal
Magnetometer
- pairs of transmitter and receiver magnetic coils are placed on the front and back of the RC and ABD
- changes in RC and ABD diameter cause changes in the magnetic forces between the coils, and this is detected as a continuous electrical signal
How are chest wall movement displayed (describe the graph)?
ABD movements on x-axis and RC movements on y-axis
- measure start, end, and total volumes for RC and ABD
- can see patterns of movement (smooth vs variable, paradoxical vs parallel)
Ideally, our Chest Wall Display should show ABD movements _____ (increasing/decreasing) as RC movements decrease
Increasing
