What are the passive relaxation forces above REL during breathing?
- expiratory forces (lungs want to get smaller)
- passive forces drive the system in expiratory direction
What happens at REL in terms of lung pressure and airflow?
- no airflow occurs
- opposing forces of lungs (want to get smaller) and thorax (want to expand) are balanced
What are the passive relaxation forces below REL during breathing?
- inspiratory muscles
- passive forces drive the system in the inspiratory direction
what muscles are active ABOVE REL to counteract passive expiratory forces during speech?
- diaphragm
- external intercostals
These inspiratory muscles slow down passive expiratory forces to control airflow for speech.
What muscles are active BELOW REL to counteract passive inspiratory forces during speech?
-Abdominal muscles.
-Internal intercostals.
These expiratory muscles are used to keep air flowing for speech.
What does a Pressure Transducer measure, and how is it calibrated?
Measures lung pressure in cm H₂O.
Calibrated by manometer
Pneumotachograph
measure airflow in cubic centimeter/second (cc/sec)
calibrated with rotometer
Respiratory Inductive Plesthymysmography (RESPRITRACE)
- lung volume
- liters (L.)
- calibrated with 1 liter spiral bag or known volume of air
Magnetometers
- measures lung volume
- litters (L)
- calibrated with some known value or 1 liter spiral bag
Basic Summary of being ABOVE REL
YOU ARE NATURALLY BREATHING OUT
WHICH IS WHY YOU NEED:
active inspiratory muscle force to stay above REL and work against passive expiratory relaxation pressure
Basic Summary of being BELOW REL
YOU ARE NATURALLY BREATHING IN
WHICH IS WHY YOU NEED
active expiratory muscle force to stay below REL to work against passive inspiratory relaxation pressure
Indirect measurement of subglottal pressure
Most cases the pressure you generate in your mouth for /p/ is equivalent to subglottal pressure
During these sounds, oral pressure approximates subglottal pressure since the vocal folds are open and the mouth is sealed.
