Intercostal muscles are the most important muscles of respiration
Muller's maneuver measures maximum inspiratory pressure (MIP) developed against a block of the trachea at RV
Valsalva maneuver measures Expiratory muscle strength - measures maximum expiratory pressure (MEP) at RV
Cough - which statement is wrong
Sensory reflex loop - RARs (rapidly adapting receptors) detect irritants and stimulate trigeminal nerve -> brain stem -> motor neurons ->respiratory muscle contractions
Sequence - deep inhalation -> forced expiration on closed glottis -> open glottis forced espiration
3 most common cause of chronic cough (> 8 weeks) post nasal drip from rhinosinusitis, asthma and GERD
Reaches a speed of 28,000 cm/sec, eject about 40,000 microdroplets which may contain >200,000 virus particles
Airflow and respiratory pressures are measured in cm of H2O because the pressure changes in the lung are so small that it is hard to see a 1 or 2 mmHg change
Regarding pressures all of the following are true except
P(alveolar) = P(barometric) at end inspiration and end expiration
P(alveolar) = P(Barometric) here is no air flow and glottis is closed
When P(alveolar) > P(barometric) the direction of airflow is - out of lungs (expiration)
PL = PA-Ppl
During Respiration the following is the sequence except
Inspiratory muscles contract -> thoracic cavity expands
Pleural pressure becomes more negative (-5 to -8 cm of H2O)
Transpulmonary pressure decreases
lungs inflate and alveolar pressure becomes subatmospheric --> air flows into the lungs until alveolar pressure equals atmospheric pressure
Boyles law
P1V1 = P2V2
During inspiration Alveolar Pressure drops and volume increases
During inspiration Pleural pressure increases (becomes more negative) and volume decreases
1,2,3 are correct
1,2 are correct
2,3 are correct
