Chapter 17 Mechanics of Breathing. About this Chapter The respiratory system Gas laws Ventilation.
Mechanics of ventilation
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Transcript of Mechanics of ventilation
Mechanics of ventilation
How the lung is supported and moved
Pneumothorax of right lung
Rotation axis
ribs
Static recoil
Interpleuralpressure
Air
flow
insp exsp
Interpleural
pressure
Tidal volume
P=T/r
↑r ↓T
P = P
↓CL
Dipalmitol fosfatidil cholin + protein
Alveoli are larger at the apex (upper panel) than base (lower)
∆V
∆P
C = ∆V / ∆P
∆P
∆V.
R=∆P / ∆V.
Number of airways increases rapidly with generation
Mechanism of dynamic compression
Work done on the lung during breathing
Transport of gas from alveoli to blood
GasMembraneblood
0.5 μm
Very thin blood-gas barrier
Limitation byperfusion
Limitation bydiffusion
Respiration at the limit: Respiration at the limit: surviving on the summit of Mt surviving on the summit of Mt
EverestEverest
Highest altitudes attained in the last century
Maximum oxygen uptake at increasing altitudes
Climbers Ranked by their Hypoxic Ventilatory Response
Alveolar Pco2 at Extreme Altitudes
Pulmonary Gas Exchange on the Everest Summit
O2 Dissociation Curves in High-Altitude Mammals
Decrease of barometric pressure with altitude
Climber on the Everest Summit
Polycythemia at 4600 m altitude
• Hemoglobin concentration 19.8 g/dl
• Arterial PO2 45 mm Hg
• O2 saturation 81%
• O2 concentration 22.4 ml/dl
DLO2 = VO2 / PAO2 Pc O2
DLCO = VCO / PACO
Time of blood flow through pulmonary capillary