Lecture 9 (Exam II) Flashcards
(107 cards)
1
Q
What is the pressure in the thorax?
A
- -4mmHg, which equals -5cmH20.
- The pressure inside the chest is subatmospheric
2
Q
Why did we switch from mmHg to cmH2O for pulmonary measurements?
A
Water is less dense and is more sensitive to changes, and thoracic pressures are really low so they needed a higher resolution.
3
Q
If you have the left side of the diaphragm working, and the right side of the diaphragm paralyzed, what will happen when you contract your diaphragm?
A
- Only the left side of the diaphragm will contract, causing the lung to sink or be pulled down.
- The right side of the diaphragm will be flaccid, causing the right lung to rise.
4
Q
What happens to the lungs when we inspire?
A
- The diaphragm contracts and pulls down the lungs which causes the lungs to expand and draw air in.
- As vthe lung stretches out, it bcreates a more negative pressure in the lungs which can suck air in from the environment.
5
Q
What happens to the lungs when we expire?
A
- The diaphragm relaxes and pushes up on the lungs.
- This allows air to be pushed out of the lungs into the environment.
6
Q
What is the main muscle for ventilation?
A
The diaphragm
7
Q
Collectively, what are the group of muscles called we use when we need to pick up the pace with ventilation?
A
the accessory muscles
8
Q
What is the issue with placing interscalene blocks?
A
It is very close to the phrenic nerve. If you accidentally block the phrenic nerve, you risk paralyzing the patients diaphragm and they won’t be able to breathe on their own.
9
Q
Eupnea
A
normal breathing
10
Q
Dyspnea
A
Shortness of breath, respiratory distress
11
Q
Apnea
A
no breathing at all
12
Q
stridor
A
noisy breathing due to airway diseases or respiratory distress
13
Q
Bradypnea
A
slow breathing
14
Q
Tachypnea
A
rapid breathing
15
Q
Orthopnea
A
A change in breathing when you change your body position. EX: going from laying to standing or standing to laying
16
Q
Hypernea
A
fast overbreathing, more than tachypnea
17
Q
hyperventilation
A
Ventilation that is occurring well in excess of metabolic demands
18
Q
Hypoventilation
A
Insufficient ventilation for metabolic demands
19
Q
Hyperinflation
A
Really big COPD lungs that are much larger than they should be. It is a result of air trapping
20
Q
Cyanosis
A
When we have a deoxyheoglobin >5mg/dL. This is the threshold that normal venous content looks like). Deoxyhemoglobin is blue and the more deoxyhemoglobin we have, the more cyanotic we are, the bluer we are.
21
Q
Hypoxia
A
a decreased amount of O2 at the level of the tissue. This is a localized problem
22
Q
Hypoxemia
A
A decreased amount of O2 in the arterial blood. This is a systemic problem, a global deficit of O2.
23
Q
Hypercapnea/ hypercarbia
A
When there is excessive CO2 in the arterial blood. You can get this with hypoventilation and COPD
24
Q
Hypocapnea/ hypocarbea
A
When there is a deficiency of CO2 in the arterial blood. You can get this with hyperventilation.
25
Hyperoxia
When O2 levels are above normal at the tissues and organs. This is a tissue specific terma nd not related to the entire system.
26
Atelectasis
The collapse of functional lung units. a collapsed portion or region of the lung. Can happen with infection in a portion of the lung where there is an issur with ventilation and perfusion in that area.
27
What does 1mmHg equal in cmH20
= 1.36H20
28
* Someone with a high lung compliance will be easier or harder to ventilate?
* Someone with a low lung compliance will be easier or harder to ventilate?
* Easier
* Harder
29
* High complaince = ___
* Low complaice = __
* Stretchy
* Rigid
30
What is the inverse oc compliance?
elastance
31
* Lungs with low compliance have ___
* Lungs with High complaince have __
* high elastance
* low elastance
32
What is transpulmonary pressure?
* The pressure used to fill the lungs up with air.
33
What is tidal volume?
* 0.5L
* The amount of air that goes in when we inspire and out when we expire
34
What is IRV?
* 2.5 L
* The amount of air that we could inspire with maxiam effort starting at the end of normal tidal volume inspiration.
35
What is ERV?
* 1.5 L
* The volume of air that we an push out o the lungs after a normal tidal volume expiration
36
What is RV?
* 1.5 L
* The amount of air that is left over in the lungs that cannot be pushed out no matter how hard we try
37
What is TLC?
* 6 L
* The maximum amount of airthat we an get into both lungs
* It is the sum total of all volumes (VT, IRV, ERV, and RV)
38
What is IC?
* 3 L
* Total amount of air we can take in starting from FRC at 3L and going to TLC at 6 L with maximal effort.
* VT + IRV
39
Whatv is FRC?
* 3 L
* The volume of air left in the lungs between breaths after you have expired your tidal volume.
* ERV + RV
40
What is VC?
* 4.5 L
* Referred to as the working volume of the lung
* The total amount of air we can forcefully inspire and expire
* The sum of IRV, VT, and ERV
41
What is resting volume?
* FRC
* 3 L
42
* How much air should you have in your lungs at the end of maximal inspiration?
* How much air should you have in your lungs at the end of maximal expiration?
* 6 L
* 1.5 L
43
What is the normal PVR of the lungs?
Very low between 40-180
44
How long is a normal breathing cycle?
5 seconds total: 2 seconds for inspiration, 2 seconds for expiration, and 1 second in between breaths.
45
What is the normal respiratory rate?
12 breaths per minute
46
What is tidal volume measured in?
Liters
47
What is intrapleural pressure measured in?
cmH2O
48
What is elastic recoil pressure/ transpulmonary pressure measured in?
cmH2O
49
What is inspiratory and expiratory airflow measured in?
Liters per second
50
What is alveolar pressure measured in?
cmH2O
51
Describe what happens at the 0 second of the respiratory cycle
* This is the pressure in between breaths.
* Barometric pressure = 0cmH2O
* Inspired air/tidal volume = 0L
* Airflow = 0L/sec
* Pip = -5cmH2O
* Recoil = +5cmH2O
* Alveolar = 0cmH20
52
Describe what happens at the 1st second of the respiratory cycle
* Diaphragm contracts, beginning of inspiration
* Barometric pressure = 0cmH2O
* Inspired air/tidal volume = 0.25L
* Insspiratory airflow = -0.5L/sec
* Pip = -6.25cmH2O
* Recoil = +5.25cmH2O
* Alveolar = -1cmH2O
53
Describe what happens at the 2nd second of the respiratory cycle
* End of inspiration.
* Barometric pressure = 0cmH2O
* Inspired air/tidal volume = 0.5L
* Airflow = 0L/sec
* Pip = -7.5cmH2O
* Recoil = +7.5cmH2O
* Alveolar = 0cmH2O
54
Describe what happens at the 3rd second of the respiratory cycle
* Diaphragm relaxes, beginning of expiration
* Barometric pressure = 0cmH2O
* Expired air/tidal volume = 0.25L
* Expiratory airflow = +0.5L/sec
* Pip = -6.25cmH2O
* Recoil = +7.25cmH2O
* Alveolar = +1cmH2O
55
Describe what happens at the 4th second of the respiratory cycle
* End of expiration.
* Barometric pressure = 0cmH2O
* Expired air/tidal volume = 0L
* Airflow = 0L/sec
* Pip = -5cmH2O
* Recoil = +5cmH2O
* Alveolar = 0cmH2O
56
* When does peak airflow for inspiration happen?
* Why is it marked with a (-) sign?
* At the 1 second mark
* The (-) sign represents air coming in to the lung and has a negative/downward deflection on the graph
57
* When does peak airflow for expiration happen?
* Why is it marked with a (+) sign?
* At the 3 second mark
* The (+) sign represents air going out of the lungs and has a positive/upward deflection on the graph.
58
What does it mean if there is a pressure gradient (delta pressure) between alveolar pressure and barometric pressure?
* Air will either be forced in or out of the lungs.
* Delta pressure = alveolar pressure - barometric pressure.
* If the delta pressure is (-), air will get sucked into the lungs. Inspiration
* If the delta pressure is (+) air will be pushed out of the lungs. Expiration
59
What lung volume are you at in between breaths?
FRC, 3L
60
What does FRC stabalize in between breaths?
* Blood gases
* Without FRC, we would have abrupt changes to blood gases in between breaths.
61
What does FRC do that keeps alveoli healthy?
Holds the alveoli open since they don't have cartilage
62
How does body position change the volume of air in your lungs?
If you lay supine, your diaphragm pushes on your lungs, which then pushes out part of your ERV and decreases the volume of ERV and FRC. We usually go from on FRC of 3L to 2L when we lay supine.
63
Why does alveolar pressure go back to 0cmH2O at the end of inspiration?
It is a result of the pressure equilibrating to the new enlarged alveolar size when we draw air into the lungs. This equilibration happens at the 2 second mark of respiration.
64
What kind of ventilation is normal breathing?
Negative pressure ventilation
65
What is the main force that pushes air out of the lungs on expiration?
Elastic recoil
66
Is the recoil that pushes air out of the lungs on expiration active recoil or passive recoil, for normal quiet breathing?
passive recoil
67
What kind of lung disease (obstructive or restrictive) is a problem with getting air out of the lungs?
Obstructive lung diseases
68
What kind of lung disease (obstructive or restrictive) is a problem with getting air into the lungs?
restrictive lung diseases
69
What balances out the tendency of the alveoli wanting to recoil in on themselves?
The negative pleural pressure in the lungs counteracts the positive recoil pressure inside the alveoli.
70
What is elastic recoil pressure?
The tendency of the alveoli to want to collapse on itself.
71
What is transpulmonary pressure?
An important force that gets air into the lung no matter how you are ventilating the lung (positive pressure or negative pressure ventilation).
It is the pressure that is available to fill the lung up with air.
72
What is another name for transpulmonary pressure?
transmural pressure
73
What happens when we increase transpulmonary pressure?
more air will get pushed into the lung
74
* When transpulmonary pressure increases, lung volume ___
* When transpulmonary pressure decreases, lung volume ___
* Increases
* decreases
75
How many west perfusion zones are there?
4
76
Pulmonary Circulation is very ___ and has a low ___
* Compliant
* resistance
77
What other function does the pulmonary circulation serve besides perfusing the lung and gas exchange?
It acts as a blood reservoir in case we need it in the incidence of mass hemorrhage.
78
According to the west perfusion zones, blood flow through the lungs is dependent on ___
gravity
The closer you are to earths center/gravity, the better perfusion of that part of the lung you get. Hence, in an upright person, the base is perfused better than the apex.
79
Which lung would you put down/closer to earths gravity to get better gas exhange and blood flow?
Good lung goes down and bad lung goes up.
80
Which zone is always off?
Zone 1
81
Which zone is sometimes on, sometimes off?
Zone 2
82
Which zones are always on?
Zones 3 and 4
83
What is zone 1 flow?
PA > Pa > Pv
84
What is zone 2 flow?
Pa > PA > Pv
85
What is zone 3 flow?
Pa > Pv > PA
86
What is zone 4 flow?
Pa > Pv > PA
87
Is zone 1 found in healthy lungs?
no, in healthy lungs, we don't have any areas that are completely turned off all the time.
88
What are the top 2 things that cause zone 1 flow?
* Positive pressure ventialtion
* Blood loss secondary to trauma
89
Why does positive pressure ventialtion cause zone 1 flow?
The pressure we are using in positive pressure ventilation compresses the vessels which stops blow flow.
90
* Where is zone 1 located in an upright person?
* In a supine person?
* upright = apex/top of lungs
* Supine = anterior portion of lungs
91
What zone has the greatest amount of PVR?
Zone 1
92
Where are pulmonary blood vessel pressures inside the lung the lowest?
Zone 1
93
What zone has the most narrow pulmonary blood vessels?
Zone 1
94
Why is the flow sometimes on and sometimes off in Zone 2?
* It is intermittent depending on what the blood pressure is.
* When pulmonary blood pressure is low, we will have less flow to this area.
* When pulmonary blood pressure is high, we will have more flow to this area.
95
What zone has a pulsatile blood flow?
Zone 2
96
What zone has the lowest PVR?
Zone 3
97
* Where is zone 3 in the upright patient?
* In the supine patient?
* Upright = base/bottom of the lung
* Supine = posterior portion of the lung
98
Where are pulmonary blood vessel pressures inside the lung the highest?
Zone 3
99
What does a high pulmonary bloos pressure do to the vessel in the lung?
Stretches out the compliant vessel making it much wider and giving us a lower PVR.
100
Which zone has continuous perfusion of the lungs through out the cardiac cycle?
Zone 3
101
Where is zone 4 located?
The very bottom portion of the lung that rests on top of the diaphragm.
102
Why is the flow in zone 4 a little bit less than in zone 3?
The flow is a little decreased due to this portion of the lung resting on top of the diaphragm. The weight of the lung pushes down on this area and slightly compresses the vessels.
The gradient here is still Pa > Pv > PA
103
What do you need in order to have blood flow in a specific area of the lung?
pulmonary arterial pressure needs to be higher than alveolar pressure.
104
What happens when alveolar pressure is higher than blood pressure?
You wont have any blood flow to the area because the compliant vessels are now collapsed.
105
What is gravity dependence?
Gravity makes blood weigh more, which causes the compliant pulmonary vessels to open up and become more distended to allow for more blood flow.
106
What holds our alveoli open?
the negative pleural pressure of -5cmH2O pulls on the outside walls of the alveoli and keeps them propped open.
107
Label the lung volumes and capacities
