Pulmonary Circulation

Question 1

Hypoxic pulmonary vasoconstriction

Answer 1

when alveolar PO2 is < 70 mmHg you get pulmonary vasoconstriction

Question 2

How does hypoxic pulmonary vasoconstriction happen?

Answer 2

constriction of small precapillary vessels

Question 3

What are some things that could case HPV?

Answer 3

airway obstruction
failure of ventilation
acute lung damage
high altitude
COPD

Question 4

What is the average normal value of ventilation-perfusion?

Answer 4

0.8

Question 5

What is the distribution of V/Q

Answer 5

ration increases from base to apex

Question 6

shunt

Answer 6

portion of cardiac output or bloodflow is rerouted

Question 7

physiologic shunt

Answer 7

bronchial blood flow

small amount of cornooary blood flow that drains directly into LV through thebesian veins and never perfuses the lungs.

Question 8

right to left shunts

Answer 8

happens if there is a defect in the wall between R and L venticals
hypoxemia always occurs
can’t be corrected by having the person breathe a high O2 gas

Question 9

left to right shunts

Answer 9

do not cause hypoxemia

oxygenated blood that just returned form lungs is added directly to R heart without going to systemic tissues

Question 10

What are some things that can cause left to right shunts

Answer 10

patent ductus arteriosus

traumatic injury