Respiratory A&P Flashcards
What volumes and capacities can NOT be measured by spirometry?
Residual Volume, therefore you also can’t measure
FRC (ERV+RV) and TLC (all volumes including RV)
Besides the lungs(!), what do vessels do in the presence of hypoxia?
Vasodilate!
In the lungs, what is the response to hypoxia?
Vasoconstrict! Due to hypoxic pulmonary vasoconstriction
What is water vapor pressure at normal body temp?
47mmHg
What is normal VO2 as mL/min? For a 70kg adult?
3.5mL/kg/min
70kg adult is 250mL/min
Residual Volume contributes to what percentage of total lung capacity?
20%
Which phenomenon is responsible for tachypnea that accompanies pulmonary embolism?
J Receptor Stimulation
What is the Most common etiology of hypoxemia in PACU ?
Atelectasis due to V/Q mismatch
In a healthy adult, dead space is about ___ ml/kg
2 ml/kg
Normal tidal volume ml/kg
6-8mL/kg
Normal m=Minute ventilation
5-8L/min
What is the Vd/Vt formula and what does it measure. What is normal?
(PaCO2 - PeCO2)/ PaCO2
Fraction of Tidal Volume that contributes to dead space.
Normal: 0.33 or 33%
ETT decreases airway dead space, but positive pressure ventilation increases dead space. Why?
PPV increases alveolar pressure which increases ventilation relative to perfusion, creating dead space
Ventilation is greatest at the ____ and poorest at the ____. Why?
Greatest at the base and poorest at the apex.
Because compliance is better in the base of the lung. You get a bigger change in volume for a given change in pressure at the base. Alveoli are already semiopen at the apex. So there net change (compliance) is not as good.
