Pulmonary Blood Flow Quiz

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What is the main cause of the development of pulmonary edema?

Decreased pulmonary arterial pressure

Increased left atrial pressure exceeding plasma colloid osmotic pressure (correct)

Decreased interstitial fluid colloid osmotic pressure

Increased systemic vascular resistance

What happens when alveolar O2 decreases to ~70% of normal?

Pulmonary capillary pressure decreases

Pulmonary arterial pressure increases

Adjacent vessels dilate, decreasing resistance by 5x

Adjacent vessels constrict, increasing resistance by 5x (correct)

What is the mean pulmonary capillary pressure?

About 28 mm Hg

About 7 mm Hg (correct)

About 23 mm Hg

About 14 mm Hg

What happens to the pulmonary capillaries when alveoli apply little to no pressure at end-exhalation?

Pulmonary capillaries are compressed (D) Signup and view all the answers

What is the main effect of alveolar vs extra-alveolar vessels on pulmonary vascular resistance?

Alveoli-filled alveoli compress capillaries, whereas larger vessels are pulled open further by elastic recoil (C) Signup and view all the answers

What happens to the resistance when alveolar O2 decreases to ~70% of normal?

Adjacent vessels constrict, increasing resistance by 5x (A) Signup and view all the answers

What happens to the cardiac output during exercise?

It can increase 4-7 times (D) Signup and view all the answers

What is the main accommodation to increased cardiac output?

Increase number of open capillaries ('Recruitment') (C) Signup and view all the answers

What are the outward fluid pressures from capillaries into interstitium?

Capillary pressure, 7 mm Hg (D) Signup and view all the answers

What happens as left atrial pressure rises in the development of pulmonary edema?

Pulmonary capillary pressures rise by about 1-2 mm Hg more (D) Signup and view all the answers

What is the effect of increased left atrial pressure exceeding plasma colloid osmotic pressure?

Fluid begins to accumulate in the lungs (A) Signup and view all the answers

Which of the following best describes the major functions of the bronchial circulation?

Supplying oxygenated blood to the conducting airways and supporting lung tissue metabolism (D) Signup and view all the answers

In which zone of the lung do alveolar pressure exceed pulmonary vascular pressure?

Zone one (D) Signup and view all the answers

How does pulmonary vascular resistance change with alterations in cardiac output or pulmonary arterial pressure?

It may change due to distention and recruitment of pulmonary vessels (A) Signup and view all the answers

What is the consequence of hypoxic pulmonary vasoconstriction on the distribution of pulmonary blood flow?

It redirects blood flow away from poorly-ventilated areas of the lung (A) Signup and view all the answers

How does inspired nitric oxide affect pulmonary vascular resistance and hypoxic vasoconstriction?

It decreases pulmonary vascular resistance and inhibits hypoxic vasoconstriction (C) Signup and view all the answers

Which of the following best describes the regional differences in pulmonary blood flow in an upright person?

Greater blood flow to the base of the lung compared to the apex (D) Signup and view all the answers

What describes zone two in the lung with respect to pulmonary vascular pressure and alveolar pressure?

Pulmonary vascular pressure exceeds alveolar pressure but is less than arterial pressure (D) Signup and view all the answers

How does pulmonary vascular resistance change with alterations in lung volume?

It changes due to alterations in alveolar and extra-alveolar blood vessels (A) Signup and view all the answers