Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
15 Cards in this Set
- Front
- Back
|
Describe the pulm. circulation.
|
-Low Pressure,Low resistance,mostly at heart height.
-PAP = 25/8 mmHg -Capillary pressure = 12-8 mmHg |
|
|
Pulm. vessels are thin-walled.
|
True.
|
|
|
Pulm. circulation receives all of the right ventricular output.(5-20 L/min)
|
True.
|
|
|
Why doesnt pulm. artery pressure rise with increased CO ?
|
due to dilatation and recruitment of pulm. vessels.
|
|
|
What happens when you lie down?
|
Blood drains from legs to lungs.(pulm. circulation serves as a reservoir for blood)
|
|
|
Pooling of blood occurs on EXPiration.
|
False.Pooling occurs on Inspiration.
-Decreased venous return to LA -Decreased CO -Decreased systolic BP on inspiration(lower than on exp) |
|
|
What is regional distribution of blood flow affected by?
|
1. Gravity
2. Arteriolar constriction in response to alveolar hypoxia |
|
|
Pulsus paradoxus occurs when the diff. of systolic BP between INSP. and EXP. is > 15 mmHg.
|
True
|
|
|
When is gas exchange most efficient?
|
When ventilation and perfusion are matched(V/Q =1) in all the 300 million AC units.
|
|
|
V/Q matching doesnt really affect CO2.
|
True.
|
|
|
Can we give 100 % O2 to a shunt?
|
NO.
|
|
|
Giving O2 in case of hypoxemia improve ventilation.
|
False.
|
|
|
What is the compensatory mechanism for regions of low V/Q ?
|
Regional vasoconstricition in areas of low alveolar Ventilation to reduce hypoxaemic effects of low V/Q units.
|
|
|
What happens when blood pools down at bottom of lungs?
|
It has an effect on the negative intrathoracic pressure(highest -ve pressure at top of lungs)----> alveoli at bottom open up on inspiration.
|
|
|
How do you assess overall effectiveness of O2 exchange in lungs?
|
Alveolar-arterial oxygen gradient.(A-a)---> PA O2 - PaO2.
|
