Phys 2 Flashcards
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:
- Source
- PaO2
- PaCO2
- Function
- Return to the heart
- Blood gas in vein
- Right ventricle via Pulmonary artery
- Low
- High
- Gas exchange in alveoli
- Pulmonary vein to Left ventricle
- high PaO2/low PaCO2
Extra Alveolar Capillaries:
- Source
- PaO2
- PaCO2
- Function
- Return to the heart
- Blood gas in vein
- Notes
- Left ventricle via aorta
- High
- Low
- Provide nutrients to and remove waste from the airways
- Pulmonary vein to left ventricle
- Low PaO2/High PaCO2
- Venous admixture
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?
- number of capillaries
- number of capillaries open
- lung volume (low or high volumes, PVR ^ a little)
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
- nitric oxide made by endothelium
- causes SM relaxation and vasodilation
- significant role in normal pulmonary blood flow
Oxygen as a modulator
- the strongest of all of them
- 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
- Hydrostatic Pressure: fluid pushing against the tissue/wall of capillary
- Oncotic Pressure: osmotic pressure of the fluids
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
πc
Oncotic Pressure: tries to pull water into the capillary
πt
Oncotic Pressure: tries to pull water into the alveolus
What three startling forces want water to go into the lungs? Which ones does not?
- πt, Pc, Pt
- πc
(Pc + Pt + πt) - πc = where will the fluid go
What is the greatest startling force?
Pc
Renin changes what to what?
angiotensinogen —> angiotensin 1
Angiotensinogen is a ___ added to the ___ by the ___.
protein, plasma, liver
How does angiotensin 1 change to 2?
- ACE (angiotensin converting enzymes)
- occurs in the lungs
*ACE also inactivates bradykinin
