Lecture 10 - Blood Flow and Metabolism

Question 1

Pulmonary Artery Catheters can be used to Directly obtain Pulmonary ______ pressure and estimate Pulmonary ______ pressure as PAOP –> this can give an estimate of Left Atrial pressure, and thus, Left Ventricular End Diastolic pressure –> this gives an idea of Left Ventricular End Diastolic Volume (aka ______).

Answer 1

Pulmonary Artery Pressure Pulmonary Venous Pressure as Pulmonary Artery Occlusion Pressure (PAOP) Preload

Question 2

Pulmonary Vascular Resistance (PVR) = (____ - ____) / ____

Answer 2

(MPAP - PAOP) / CO, where MPAP is Mean Pulmonary Arterial Pressure; PAOP is Pulmonary Artery Occlusion Pressure; CO is Cardiac Output.

Question 3

The pulmonary circulation has “Passive” mechanisms of control/ “Reserves.” What changes do these mechanisms elicit in healthy lung when pulmonary arterial pressure increases?

Answer 3

This basically means Capillaries in the lungs that are not in use at rest (the “reserves”) can be recruited when Pulmonary arterial pressure rises and/or CO increases. Remember that essentially adding more capillaries INCREASES the total cross sectional area, and thus DECREASES Pulmonary Vascular Resistance.

Question 4

Pulmonary Vascular Resistance (PVR) is lowest at _____. This is because alveolar vessels are essentially squeezed at _____ lung volume, leading to widening of the extra-alveolar vessels, and alveolar vessels widen at _____ lung volume, leading to narrowing of extra-alveolar vessels.

Answer 4

FRC (end of exhale during tidal volume)

High

Low

Question 5

Active control of PVR is brought on by a state of ______. Alveolar vessels ______ in resposne –> in the case of Regional _____, this helps direct blood flow to functioning aveolar-capillary units without much change in PVR. In the case of Generalized _____, there is a global response by the Alveolar vessels, so PVR will ______.

The lungs respond irrespective of neural innveration!

Answer 5

Hypoxia

Vasoconstrict

Regional Hypoxia

Generalized Hypoxia

Increase

Question 6

Inhaled NO will actually go to ______ (normal or blocked up alveoli?), which helps diver more blood flow –> Conserves O2 diffusion into blood.

Answer 6

Normal

Question 7

Remember that the Lungs act as a _____ for blood, holding about ____L.

Answer 7

Resivoir

0.5L