3/19: Pulmonary Circulation Flashcards
How does pulmonary circulation compare to systemic?
Lower pressure
Lower resistance
Higher compliance
Lower volume
How do pulmonary arteries compare to systemic?
Larger
Walls are thin and distensible - large compliance
How do pulmonary capillaries compare to systemic?
More distensible
There is no population that is closed at rest
How do pulmonary veins compare to systemic veins?
Much shorter than systemic
What does bronchial circulation supply?
Oxygen and nutrients to the tracheobronchial tree down to the terminal bronchioles and also pulmonary blood vessels, visceral pleura, nerves, and hilar lymph nodes
Describe the blood in the left atrium
has little less oxygen (95) than in pulmonary capillaries (100) since some deoxygenated blood from
bronchial veins mixes with oxygenated blood in pulmonary
Bronchial flow is about ______% of cardiac output of the left ventricle
2%
How structures in the respiratory zone receive oxygen?
Directly by diffusion from the
alveolar air (doesn’t need bronchial circulation) and receive nutrients from the mixed venous blood in pulmonary circulation
What is the pressure and resistance of pulmonary circulation?
Low pressure
Low resistance
Describe pulmonary vessels
are far more distensible/compliant and able to alter their size and adjust to changing pulmonary volumes
What is the pressure of the pulmonary artery?
High pressure, pulsatile nature
What is the pressure of the pulmonary capillary?
pressure is not pulsatile anymore.
This pressure is right around 7 (creates pressure for
FILTRATION though the pulmonary capillaries) this
pushes fluid out of the capillaries
What is the pressure of the left atrium?
Low pressure (around 2)
What does pulmonary blood volume account for?
9% of blood volume (450 mL) but is highly variable
When does pulmonary blood volume increase?
during inspiration, laying down, and disease states
What is the flow in pulmonary circulation not as prone to compared to systemic?
Hypertension
How does an increase in flow (CO) to the lungs decrease pulmonary resistance through?
- Recruitment of pulmonary capillaries
a. Opening and perfusing more - Distension of pulmonary capillaries
a. **This is why pulmonary
circulation has compliance