Pulmonary Blood Flow Flashcards
During diastole, which chamber(s) of the heart have the greatest pressure?
atria
During systole which chamber(s) of the heart have the greatest pressure?
left ventricle
From where do alveolar capillaries receive blood?
R ventricle
What is the oxygen and carbon dioxide composition of blood entering the alveolar capillaries from the R ventricle?
low oxygen
high carbon dioxide
What is the purpose of alveolar capillaries?
gas exchange b/w blood and air
From where do extra alveolar capillaries receive blood?
L ventricle
What is the oxygen and carbon dioxide composition of blood entering the extra alveolar capillaries from the L ventricle?
high oxygen
low carbon dioxide
What is the purpose of extra alveolar capillaries?
deliver oxygen and nutrients to the tissue of the lungs
How does blood from the extra alveolar capillaries that “fed” the lung tissue get back to the heart?
pulmonary vv
-venous admixture
Which is larger: pulmonary vascular resistance or total peripheral resistance?
total peripheral resistance
When during the respiratory cycle is PVR the highest?
when lung volumes are very low or very high
What is the equation that relates pulmonary blood pressure and pulmonary vascular resistance?
PBP = CO x PVR PBP = SV x HR x PVR
In which zone of the lung is blood pressure the smallest?
Zone 1, the apex
-bc it’s slightly above the level of the heart
In which zone of the lung are the alveoli the most expanded at rest?
Zone 1, the apex
In which zone of the lung is blood flow the highest?
Zone 3, the base
What stimulates the production of nitric oxide?
shear stress
What produces nitric oxide?
endothelium
What does nitric oxide do in the body?
smooth muscle relaxation
vasodilation
-significant role in pulmonary blood flow
What do endothelin 1 and thromboxane A2 do in the body?
vasoconstriction
Where are endothelin 1 and thromboxane A2 made?
in the lungs
When are endothelin 1 and thromboxane A2 present in the body?
present under pathological conditions
- not under normal conditions
- produced by immune system activation
Why is it important that capillaries not leak water into the alveoli?
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”
What body system is responsible for removing the water so that alveolar gas exchange can happen properly?
lymphatics
Where is angiotensin I converted into angiotensin II?
ACE converts angiotensin I into angiotensin II in the lung
In addition to converting angiotensin I to angiotensin II, what is another role of ACE in the lungs?
inactivates bradykinin
-pts on ACE inhibitors may develop a cough d/t accumulation of bradykinin
True or False: the lung produces leukotrienes and prostaglandins in response to immune system activation
True
Where are prostaglandins E2 and F2-alpha removed from circulation?
in the lungs
Where are leukotrienes removed from circulation?
in the lungs
