Chapter 15 The Respiratory System Flashcards
Atmosphere
160 PO2; 0.15 PCO2
Alveolar air
104 PO2; 40 PCO2
Systemic venous blood (to pulmonary arteries)
40 PO2; 45 PCO2; 70-75% hemoglobin saturation
Systemic arterial blood (from pulmonary veins)
100 PO2; 40 PCO2; 95-100% hemoglobin saturation
Tissue fluid
40 PO2; 50 PO2
Partial pressure
calculated by % of gas mixture x total pressure=PGAS
Ex. O2 in the atmosphere 21%x760mm Hg=160 mm Hg (PO2)
Ex CO2 in atmosphere 0.04%x760mm Hg=0.15 mm Hg (PCO2)
Tidal volume
amount of air involved in 1 normal inhalation, exhalation 500 mL
Minute respiratory volume (MRV)
amount of air inhaled & exhaled in 1 min.
tidal volume x # of respirations/min
12-20/min
Inspiratory reserve
amount of air, beyond tidal volume, that can be taken in with deepest possible inhalation
2000-3000 mL
Expiratory reserve
amount of air, beyond tidal volume, expelled with most forceful exhalation
1000-1500 mL
Vital capacity
tidal volume + inspiratory reserve + expiratory reserve
amount of air involved in deepest inhalation followed by most forceful exhalation
3500-5000 mL
Residual air (volume)
amount of air that remains in lungs after most forceful exhalation
1000-1500 mL
Atmospheric pressure
pressure of air around us
760 mm Hg
Intrapleural pressure
pressure within potential pleural space between parietal pleura and visceral pleura - slightly below atmospheric pressure - negative pressure
Intrapulmonic pressure
pressure within bronchial tree and alveoli - fluctuates below and above atmospheric pressure during each cycle of breathing
