PULMONARY VENTILATION & CIRCULATION Flashcards
- pressure of the fluid between the lung pleura and chest wall pleura
PLEURAL OR PARIETAL ?
pleural pressure
- start of inspiration pleural pressure
- 5 or -7.5 cm H2O ?
-5 cm H2O
- during inspiration PLEURAL PRESSURE
-7.5 cm H2O
alveolar pressure during respiration
- during inspiration: -1cm H2O (enough to pull 0.5 liter of air into the lungs in the 2 seconds)
- During expiration: +1 cm H2O (forces the 0.5 liter of inspired air out of the lungs)
- Air Pressure Inside the Lung Alveoli
ALVEOLAR PRESSURE (0 cm H2O pressure)
- Difference between Alveolar and Pleural Pressures
- Measure of recoil pressure (elastic forces in the lungs)
alveolar or transpulmonary
transpulmonary pressure
- a surface-active agent in water, greatly reduces the surface tension of water
SURFACTANT
LUNG COMPLIANCE transpulmonary pressure
-100 or -200 ?
-200 ml of air/cm H2O transpulmonary pressure
- Required to expand air-filled lungs are about three times as great as those required to expand lungs filled with saline solution.
surfactant or transpleural pressure ?
transpleural pressure
tissue elastic forces : 1/3
fluid-air surface tension forces: 2/3
- elastic contractile force of the entire lungs.
surface or pleural tension ?
surface tension elastic force
Low-pressure, High-flow
Circulation
venous blood
carry blood to
the alveolar capillaries for gas exchange
PULMONARY ARTERY or VEIN?
PULMONARY ARTERY
return the blood to the left
atrium
PULMONARY ARTERY or VEIN?
PULMONARY VEIN
Right Ventricle
SYSTOLIC AND DIASTOLIC PRESSURE
systolic pressure - about 25 mm Hg ▪diastolic pressure - averages about 0 to 1 mm Hg
pulmonary artery systolic, diastolic and mean
systolic: 25
diastolic: 8
mean: 15
mean pulmonary
capillary pressure
7mmHg
PULMONARY BLOOD FLOW
450 0R 400 mL?
450 mL
70mL in Pulmonary Capillary
a powerful local vasoconstrictor of both arterioles and veins
Thromboxane A2 or Prostacyclin (prostaglandin I2)
Thromboxane A2
a potent local vasodilator
Prostacyclin (prostaglandin I2)
increases
fluid filtration
pulmonary fluid or edema ?
pulmonary edema
accumulation of large amounts
of free fluid in the pleural
space
• “edema of the pleural cavity”
pleural fluid or effusion
pleural effusion
