In the normal individual in the upright position
** the negative intrapleural pressure is greater (ie., more negative) in the upper lung regions
**Ventilation is more effective in the lower lung regions
**the intrapleural pressure is always below atmospheric pressure during a normal ventilatory cycle
When lung compliance decreases, the patient commonly as
*an increased ventilatory rate and *a decreased tidal volume
When arranged for flow (V), Poiseuille's law states that V is
*directly proportional to P and *inversely proportional to n
During a normal exhalation, the
*intra-alveloar pressure is greater than the atmospheric pressure and *intrapleural pressure is less than the atmospheric pressure
Assuming that pressure remains constant, if the radius of a bronchial airway through which gas flows at a rate of 400 L/min is reduced to one-half of its original size, the flow through the bronchial airway would change to
The difference between the alveolar pressure and the pleural pressure is called the
According to Laplace's law, if a bubble with a radius of 4 cm and a distending pressure of 10cm H2O is reduced to a radius of 2 cm, the new distending pressure of the bubble will be
20 cm H2O
If alveolar unit A has one-half the compliance of alveolar unit B, then the
*volume in unit B is two times greater than volume in unit A and *time constant of unit B is twice as long as that of unit A
If a patient weighs 175 pounds and has a tidal volume of 550mL and a respiratory rate of 17 breaths/min, what is the patient's minute alveolar ventilation?
Part I: If a patient generates a negative intrapleural pressure change of - 8cm H2O during inspiration, and the lungs accept a new volume of 630 mL, what is the compliance of the lungs?
79 mL/cm H2O
Part II: If the same patient, 6 hours later, generates an intrapleural pressure of -12 cm H2O during inspiration, and the lungs accept a new volume of 850 mL, what is the compliance of the lungs?
70 mL/cm H2O
If a patient produces a flow rate of 5 L/sec during a forced exhalation by generating a transairway pressure of 20 cm H2O, what is the patient's Raw?
4 cm H2O / L / sec
As Raw increases, the patient commonly manifests
*a decreased ventilatory rate and * an increased tidal volume
If the radius of a bronchial airway, which has a driving pressure of 2 mm Hg, is reduced by 26 percent of its original size, what will be the new driving pressure required to maintain the same gas flow through the bronchial airway?
In the healthy lung, when the alveolus decreases in size during a normal exhalation, the
*surface tension decreases and *surfactant to alveolar surface area increases