Lecture 10 (Exam II) Flashcards
(76 cards)
1
Q
When is pleural pressure more negative?
A
at really high lung volumes (TLC)
2
Q
When is pleural pressure more positive?
A
at really low lung volumes (RV)
3
Q
When is total PVR decreased?
A
at FRC
4
Q
When is PVR the lowest during the respiratory cycle?
A
in between breaths at FRC
5
Q
When is total PVR increased?
A
At TLC and RV
6
Q
Increasing lung volume from FRC to TLC will increase or decrease PVR?
A
Increase
7
Q
Decreasing lung volume from FRC to RV will increase or decrease PVR?
A
increase
8
Q
What 2 components does total pulmonary vascular resistance consist of?
A
- Large pulmonary vessels called the extra-alveolar blood vessels.
Small pulmonary vessels called the Alveolar blood vessels.
9
Q
Alveolar PVR + extra-alveolar PVR =
A
total alveolar PVR
10
Q
What are the extra-alveolar blood vessels primarily affected by?
A
- Pleural pressure. The negative pleural pressure pulls on the walls of these vessels and makes them wider.
11
Q
- The more negative our pleural pressure is, the ___ our extra-alveolar PVR will be.
- This will cause the vessel to be ___.
A
- lower.
- Wider
12
Q
- The more positive our pleural pressure is, the ___ our extra-alveolar PVR will be.
- This will cause the vessel to be narrower
A
- higher
- Narrower
13
Q
Extra-alveolar PVR is very ___ at RV, because ___
A
- high
- We are at the lowest lung volume which means our pleural pressure is more positive
14
Q
Extra-alveolar PVR is very ___ at TLC, because ___
A
- low
- We are at the highest lung volume, which means our pleural pressure is more negative.
15
Q
Positive pleural pressure when expiring all the way to RV will do what to the extra-alveolar vessels?
A
compress them and make them more narrow.
16
Q
Where are the alveolar vessels in the lung attached to?
A
directly to the alveoli, and imbedded in the alveolar wall
17
Q
What is another name for the alveolar vessels in the lungs?
A
Pulmonary capillaries
18
Q
What is the behavior of the alveolar vessels compared to the extra-alveolar vessels?
A
The exact opposite
19
Q
What are the alveolar blood vessels primarily affected by?
A
They are affected by how large the volume is in the alveoli.
20
Q
What happens to the alveolar blood vessels as we inspire and put more air/volume into the alveoli?
A
The vessels/capillaries stretch out and becomes very thin and long as it stretches out around the alveoli
21
Q
The more volume you put into the lungs on inspiration, the more ___ the alveoli get, the more ___ the alveolar blood vessels get, and the ___ the alveolar PVR
A
- Stretched out
- stretched out, thin, and narrow
- Higher
22
Q
What happens to the alveolar blood vessels as we expire and push more air/volume out of the alveoli?
A
The vessels/capillaries shrink in size, and become short, fat, and wide.
23
Q
The less volume you have in the lungs on expiration, the ___ the alveoli get, the ___ alveolar blood vessels get, and the ___ the alveolar PVR
A
- smaller
*smaller, shorter, fatter, and wider - Lower
24
Q
A
25
Alveolar PVR is very low at ___, because ___
* RV
* because there is less volume in the alveoli and the vessels become wider
26
Alveolar PVR is very high at ___, because ___
* TLC
* Because there is more volume in the alveoli and the vessels become narrower
27
Where does gas exchange happen in the lungs?
at the level of the alveoli and its imbedded alveolar capillary.
28
* Is pulmonary blood flow from the right side of the heart an active or passive force that affects PVR?
* Why?
* Passive force
* because it doesn't involve pulmonary blood vessels conswtricting or relaxing
29
What happens to the PVR when the right heart cardiac output increases?
PVR decreases
30
The more blood our heart pumps, the ___ the PVR
lower
31
As opposed to systemic vasculature, pulmonary vasculature is very ___, and their diameter can easily be increased by ___ the amount of blood that is getting pushed through them.
* compliant
* increased
32
The higher the cardiac output from the right heart, the ___ blood that gets pumped into the pulmonary vasculature, the more ___ the pulmonary vessels become, and the ___ the PVR.
* more
* distended and stretched out
* lower
33
The lower the cardiac output from the right side of the heart, the ___ blood that gets pumped into the pulmonary vasculature, and the ___ the PVR.
* less
* higher
34
Right sided heart failure will cause a ___ in cardiac output, which will cause an ___ in PVR, which will then cause an even greater ___ in cardiac output.
* decrease
* increase
* decrease
35
Why are some areas of the lung not perfused at all times?
As a product of lung protection and conservation
In the event you breathe in harmful chemicals, the alveoli that aren't currently being perfused or ventialted will be protected.
36
* How does recruitment in the lungs happen?
* Does it decrease or increase PVR?
When we put more blood in the lung vessels from an increased right heart CO, more pathways in the lung for blood to go through open up. Recruitment decreases PVR
37
* How does distension in the lungs happen?
* Does it lower or increase PVR?
* When we put more blood in the lung vessels from an increased right heart CO, the vessels stretch out and get wider.
* Distension decreases PVR.
38
What does distension and recruitment of the lungs do for the right side of the heart?
They both keeo the right side of the heart in check by helping move more blood flow through the lungs.
39
The less pathways the blood can go through, and the less compliant/narrower the pulmonary vessels are will ___ the PVR in a person who has an increased right heart cardiac output.
increase
40
* What is the biggest influence on passive PVR?
* What is the second biggest influence?
* Gravity
Lung volume
41
What are passive influences that increase PVR? (7)
* Increased lung volume from FRC to TLC
* Decreased lung volume from FRC to RV.
* Decreased right heart cardiac output
* Gravity independent regions of the lungs (apex in an upright person)
* Increased interstitial pressure in the lungs
* Thicker blood viscocity
* Positive pressure ventilation
42
What are passive influences that decrease PVR? (6)
* Increased right heart cardiac output
* Increased pulmonary artery pressure
* Increased left atrial pressure
* gravity dependent regions of the lungs (base in an upright person)
* Thinner blood viscocity
* Moderate exercise
43
What are active influences that increaase PVR? (12)
Things that vasoconstrict
* Increased sympothetic stumulation
* Norepi
* Epi
* Alpha agonists
* PGF-2a
* PGE2
* Thromboxane
* Endothelin
* Histamine
* Alveolar hypoxia
* Alveolar hypercapnea
* Low pH of mixed venous blood
44
What are active influences that decrease PVR? (7)
Things that vasodilate
* Increased parasympathetic tone
* Acetylcholine
* Beta agonists
* The prostaglandin PGE-1
* The Prostacyclin PGI-2
* Nitric oxide
* bradykinin
45
What are the 2 main features of a healthy lung?
* Capillaries imbedded in the alveoli
* a dry lung
46
For dry atmospheric N2:
* What is the concentration?
* What is the partial pressure?
* Concentration = 79%
Partial pressure = 600.3 mmHg
47
For dry atmospheric O2:
* What is the concentration?
* What is the partial pressure?
* Concentration = 21%
* Partial pressure = 159mmHg
48
For dry atmospheric CO2:
* What is the concentration?
* What is the partial pressure?
* Concentration = 0.04%
* Partial pressure = 0.3mmHg
49
What is the total atmospheric pressure at sea level under normal conditions?
* 760mmHg
* 760torr
* 1 atm
50
What is the pressure that is driving all of the gas movement in and out of the lungs related to?
atmospheric pressure
51
What is atmospheric pressure the product of?
Gravity
52
* Atmospheric pressure at the top of a mountain is ___ than the pressure at sea level
* Atmospheric pressure at the bottom of the ocean is ___ than the pressure at sea level.
* Lower (due to less effects of gravity)
* Higher ( due to increased effects of gravity)
53
What 2 things do you need to get gas into the body?
* gas
* pressure to force the gas into the body
54
What is the formula for partial pressure?
PP of a gas = gas concentration x total atmospheric pressure
55
Even though the atmospheric ___ will change with increases or decreases in altitude, the atmospheric ___ will always stay the same.
* total pressure and partial pressure
* concentration
56
What must be taken into account when calculating inspired gas?
Humidity at a pressure of 47mmHg must be subtracted from the total atmospheric pressure of 760mmHg.
57
For inspired O2:
* What is the partial pressure?
149mmHg
58
For inspired CO2:
* What is the partial pressure?
0.3mmHg
We usually just use the value of 0mmHg
59
For inspired N2:
* What is the partial pressure?
564
60
* What is water vapor?
* What does it do to our inspired air?
* a gas
* It warms and humidifies the inspired gases up and dilutes/displaces those gases as we breathe in.
61
What other inspired things can water vapor dilute and displace?
Volatile anesthetics
62
For alveolar O2:
* What is the concentration?
* What is the partial pressure?
* 13.7%
* 104mmHg
63
For alveolar CO2:
* What is the concentration?
* What is the partial pressure?
* 5.3%
* 40mmHg
64
For alveolar N2:
* What is the concentration?
* What is the partial pressure?
* 75%
* 569mmHg
65
* Of our total inspired tidal volume of 0.5L, how much of that makes it al the way into the lungs for gas exchange?
How much gets trapped in the anatomical dead space of the upper airways?
* 350mL
* 150mL
66
When we inspire fresh air and it equilibrates with the pulmonary capillary blood surrounding the alveoli, our PAO2 will ___ and our PACO2 will ___
* increase (from 40 to 100mmHg)
* decrease (From 45 to 40mmHg)
67
Is CO2 or O2 more soluble in blood?
* CO2 is more soluble and O2 is less soluble.
68
* What is the PaO2 if systemic arterial blood?
* What is the PaCO2 of systemic arterial blood?
* O2 = 100mmHg (97.4mmHg is the more technical number)
*CO2 = 40mmHg
69
* What is the PO2 of systemic deoxygenated venous blood/pulmonary arterial blood from the right side of the heart?
* What is the PCO2 of systemic deoxygenated venous blood/pulmonary arterial blood from the right side of the heart?
* O2 = 40mmHg
*CO2 = 45mmHg
70
Pulmonary arterial blood should have the same gas characteristics as ___
systemic deoxygenated venous blood.
71
Pulmonary venous blood should have the same gas characteristics as ___
systemic arterial blood
72
What is the slight difference in pulmonary venous PO2 and arterial PaO2?
* Pulmonary venous O2 = 104mmHg, while arterial PaO2 = 100mmHg.
* This is because the deoxygenated bronchiolar admixture gets added to the pulmonary venous blood when it returns to the left side of the heart.
Since that small amount of admixture is deoxygenated, it ends up lowering the arterial PaO2 just a little bit.
73
What percent of cardiac output perfuses the bronchiolar/lung tissues?
1%
74
Why should alveolar nitrogen partial pressure always be similar to the inspired nitrogen partial pressure?
Because we don't use nitrogen in the lungs for gas exchange.
75
How does age affect arterial PaO2?
As you age from 20 to 90 years old, your PaO2 will decrease overtime from 100mmHg to 80mmHg.
76
At what age do things start to go down hill in our lungs?
age 20
