Pressure in the right and left atrium
both are 15/4
Pressure in the right ventricle
25/0
Pressure in the left ventricle
120/0
Diastole pressure is higher in…
the atrium than ventricles
Pressure in the pulmonary artery
25/15 (PBP)
Pressure in the aorta
120/80
Alveolar Capillaries:
Extra Alveolar Capillaries:
BP=__ X __
CO X TPR
blood pressure= cardiac output X resistance to blood flow
PBP= __ X __
CO X PVR
(pulmonary blood pressure = cardiac output X pulmonary vascular resistance)
-PVR is low when compared to systemic resistance
CO
5L/min
What does fight/flight do in the lungs?
nothing…it doesn’t really get there
Does PVR increase or decrease during exercise?
decreases because more pulmonary capillaries open up to increase CO
What does PVR depend on?
Zone I
Apex. Slightly above the heart, and therefore the BP is reduced. But the alveoli are slightly expanded, so blood flow is less.
Zone II
Pulmonary A/V. The BP is slightly higher because it is at the same level as the heart. The alveoli are average size, and the blood flow is normal.
Zone III
Base. BP is high because it is below the heart. The alveoli are smaller, and blood flow is greater.
NO
Oxygen as a modulator
- BVs relax with increased O2, and they constrict with low levels
Endothelin 1
-made in the lungs, and acts as a vasoconstrictor
-only works during pathologic conditions
(thromboxane A2 is basically the same thing)
Hypoxia in whole system–>
whole lung vasoconstrictor–> increase PVR–> increased pulmonary BP–> right heart failure–> right ventricle hypertrophies/peripheral edema
Starling Forces
Pc
Hydrostatic Pressure: the blood pressure in the capillary; tries to push fluid into the alveoli from the capillary
Pt
Hydrostatic Pressure: pushes fluid into the alveoli from the capillary