Gas Transport 2 Flashcards

1
Q

What factors affect overall pulmonary vascular resistance

A
  1. Passive factors: Factors that when changes cause secondary changes to vascular resistance by imposing a passive increase or decrease in caliber of individual blood vessels and/or total vascular cross-sectional area
  2. Active factors: Factors that cause an active increase or decrease in the caliber of blood vessels by altering vasomotor tone
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What factor is most important in determining pulmonary vascular resistance due to pulmonary circulation structure/architecture

A

Passive Factors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are 3 passive factors to decrease pulmonary vascular resistance

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How do passive factors decrease pulmonary vascular resistance

A

1) Pulmonary vessels are distensible and offer little resistance to stretched so increased arterial and venous pressures and blood volume can increase the cross-sectional area of flow therefore decreasing resistance
2) Recruitment: Occurs with increased arterial perfusion (see image)
3) Distention: Occurs particularly with increased left atrial back pressure (venous) (see image)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are 3 passive factors to increase pulmonary vascular resistance

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How do passive factors increase pulmonary vascular resistance

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Describe the 3 blood flow zones of the lungs

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Describe the 4 zones of the lungs and the difference in blood flow and pressure

A

Zone 1 = alveolar pressure is greatest (collapse on vessel by alveoli)
Zone 2 = arterial pressure greatest resulting in waterfall
Zone 3 = arterial and venous pressure are greater than alveolar pressure resulting in distention
Zone 4 = arterial pressure is greatest but also interstitial pressure is present from weight of lung which is greater than venous or alveolar pressure which is causes decrease in blood flow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How does perfusion change when laying in supine

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are 3 types of active factors

A

Regulation:
1) Neural
2) Cardiac
3) Chemical

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Describe neural global regulation

A

Uses:

1) Nervous system
-sympathetic = vasoconstriction
-parasympathetic = vasodilation

2) Reflexes
-increased blood pressure (baroreceptors) decreases pulmonary vascular resistance
-decreases in oxygen or pH (aortic body chemoreceptors) increases pulmonary vascular resistance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Do active factors have a smaller or bigger role than passive factors

A

Much smaller

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Describe cardiac global regulation (why would hypoxemia cause increased pulmonary vascular resistance

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Describe chemical regional regulation (aka regional hypoxemia)

A

Occurs with local hypoxemia where decreased alveolar PO2 causes vasoconstriction and decreased blood flow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Explain this image

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

List vasodilators and constrictors

A