Pulmonary Blood Flow

Question 1

During diastole, which chamber(s) of the heart have the greatest pressure?

Answer 1

atria

Question 2

During systole which chamber(s) of the heart have the greatest pressure?

Answer 2

left ventricle

Question 3

From where do alveolar capillaries receive blood?

Answer 3

R ventricle

Question 4

What is the oxygen and carbon dioxide composition of blood entering the alveolar capillaries from the R ventricle?

Answer 4

low oxygen

high carbon dioxide

Question 5

What is the purpose of alveolar capillaries?

Answer 5

gas exchange b/w blood and air

Question 6

From where do extra alveolar capillaries receive blood?

Answer 6

L ventricle

Question 7

What is the oxygen and carbon dioxide composition of blood entering the extra alveolar capillaries from the L ventricle?

Answer 7

high oxygen

low carbon dioxide

Question 8

What is the purpose of extra alveolar capillaries?

Answer 8

deliver oxygen and nutrients to the tissue of the lungs

Question 9

How does blood from the extra alveolar capillaries that “fed” the lung tissue get back to the heart?

Answer 9

pulmonary vv

-venous admixture

Question 10

Which is larger: pulmonary vascular resistance or total peripheral resistance?

Answer 10

total peripheral resistance

Question 11

When during the respiratory cycle is PVR the highest?

Answer 11

when lung volumes are very low or very high

Question 12

What is the equation that relates pulmonary blood pressure and pulmonary vascular resistance?

Answer 12

PBP = CO x PVR
PBP = SV x HR x PVR

Question 13

In which zone of the lung is blood pressure the smallest?

Answer 13

Zone 1, the apex

-bc it’s slightly above the level of the heart

Question 14

In which zone of the lung are the alveoli the most expanded at rest?

Answer 14

Zone 1, the apex

Question 15

In which zone of the lung is blood flow the highest?

Answer 15

Zone 3, the base

Question 16

What stimulates the production of nitric oxide?

Answer 16

shear stress

Question 17

What produces nitric oxide?

Answer 17

endothelium

Question 18

What does nitric oxide do in the body?

Answer 18

smooth muscle relaxation
vasodilation

-significant role in pulmonary blood flow

Question 19

What do endothelin 1 and thromboxane A2 do in the body?

Answer 19

vasoconstriction

Question 20

Where are endothelin 1 and thromboxane A2 made?

Answer 20

in the lungs

Question 21

When are endothelin 1 and thromboxane A2 present in the body?

Answer 21

present under pathological conditions

• not under normal conditions
• produced by immune system activation

Question 22

Why is it important that capillaries not leak water into the alveoli?

Answer 22

bc alveoli are responsible for gas exchange from air to blood and the oxygen that needs to be delivered to the blood isn’t water soluble

-the alveoli must be kept “dry”

Question 23

What body system is responsible for removing the water so that alveolar gas exchange can happen properly?

Answer 23

lymphatics

Question 24

Where is angiotensin I converted into angiotensin II?

Answer 24

ACE converts angiotensin I into angiotensin II in the lung

Question 25

In addition to converting angiotensin I to angiotensin II, what is another role of ACE in the lungs?

Answer 25

inactivates bradykinin

-pts on ACE inhibitors may develop a cough d/t accumulation of bradykinin

Question 26

True or False: the lung produces leukotrienes and prostaglandins in response to immune system activation

Answer 26

True

Question 27

Where are prostaglandins E2 and F2-alpha removed from circulation?

Answer 27

in the lungs

Question 28

Where are leukotrienes removed from circulation?

Answer 28

in the lungs