Exam 2 - Lecture 2 Flashcards
Standard pressure in the thorax
-5cmH2O
How many leaflets does the diaphragm have?
2
What happens if one side of the diaphragm is paralyzed?
The non-paralyzed side goes down, and the paralyzed side goes UP
How high do the lungs go? What is the top called?
Past rib 1 and in some people, all the way past the clavicle
apex
What are the pleural linings around the lungs called?
Surface on the lungs: visceral pleura
surface on inside of chest: Parietal pleura
Where does the diaphragm connect to bone?
What about accessory muscles?
On the lumbar spine on each side
Base of skull/top of neck
What is the job of the accessory muscles outside of aiding with breathing (puling ribcage up)?
Prevent the thorax from being pulled down as the diaphragm contracts.
Tendons connect _____ to _______, and ligaments connect _______ to ______
Muscle to bone
Bone to bone
What is the red diaphragm muscle called and what is the white called?
Skeletal muscle; Central TENDON (even though its not connected to a bone)
What does the heart sit on top of?
Central tendon of diaphragm
What’s the risk with doing a regional brachial plexus block?
Paralyzing the phrenic nerve. You only need 1 to survive, but if their lungs are already shit, ya may be fucked.
How many generations of airways do we have?
24
What generation is the trachea and bronchi?
Zero and One
Where does generation 2 start?
Once the left and right bronchi start splitting up into further sections.
If he points to just below the bifurcation of the trachea and asks what generation that is, that is still generation one
What zone are bronchioles in?
Conducting zones
They do not exchange gases.
What zones are respiratory bronchioles? What do they sometimes have?
Transitional zones, still no gas exchange EXCEPT when they have small notches on them which do have very little gas exchange occurring.
What are respiratory zones?
Actual gas exchange occurs here – Alveolar ducts, alveolar sacs
What diameter is the average adult trachea?
2cm
What’s the average diameter of an alveolar sac?
0.04cm (which is 0.4mm!!!)
Which structures have cartilage supporting them and keeping that part of the airway open? Which one doesn’t?
Trachea, bronchi, bronchioles
alveoli, entirely soft tissue and is only kept open by pressure.
Normal breathing
Eupnea, 12bpm
Stridor definition
“funny” sounds from lungs
asthma, tumor, constricted airway
sounds like a recorder?
Hyperpnea
Fast, over breathing
similar to tachypnea but I think over breathing is the term to think about here?
Hyperventilation
Breathing well in excess of metabolic demands
Tachypnea
rapid breathing
Hyperinflation
Over inflated lungs, typically COPD. Lungs lose connective tissue that make it easier to expand, and lose recoil.
Cyanosis
Deoxyhemoglobin build up, its blue, and the more we have, the more cyanotic we are
What’s the amount of deoxyhemoglobin that classifies cyanosis?
> 5g/dL of blood
Hypoxia
decreased amount of O2 at level of tissues
LOCALIZED PROBLEM
Hypoxemia
Lower oxygen in entire system, typically measured in arterial blood.
Hypercapnia
Excessive CO2
Hypocapnia
Low CO2
Hyperoxia
greater level than normal oxygen level, typically tissue specific.
Atelectasis
collapsed portion/region of lung. caused by infection, looks patchy.
1mmHg = ? cmH2O
1.36 cmH2O
Why did they switch from mmHg to cmH2O for pulm?
Water is less dense and is more sensitive to sensitivity changes, and thoracic pressures are really low so they needed higher resolution.
The pressure in the chest is ______ (not a #)
Sub-atmospheric
How is pressure abbreviated?
Capital P
Content
Gas variable, quantity.
E.g. oxygen content numbers are 20mL/O2/dL (free and bound oxygen)
How is arterial abbreviated?
lowercase a
PaO2
How is alveolar abbreviated?
Uppercase A
PAO2
How is ventilation abbreviated?
Uppercase V, typically measured in volume such as VT or VE
Quantity per minute example
e.g. 250mL/O2/min, VO2
Per unit of time is almost always per _______, and this is signified by what?
minute; the dot above the V means per minute
Inverse of compliance is
Elastance
Individual volumes are combined into
capacities
Standard volume per breath
500mL
Total capacity of lungs in a healthy adult with maximum amount of air
6L
What are the volumes that make up the total capacity?
-Inspiratory reserve volume (IRV)
-Tidal volume (VT)
-Expiratory reserve volume (ERV)
-Residual volume (RV)
Which volumes form functional residual capacity (FRC?)
ERV and RV
What combines to form inspiratory capacity?
IRV and VT
What’s the volume of FRC?
3L
1.5L from each ERV and RV
What is FRC?
Amount left in lungs after exhalation/in between breaths.
How much volume do we have left in our lungs after we exhale normally?
3L
Why do we still have oxygen while holding breath?
FRC
What does FRC stabilize?
Blood gases
without it, we would have abrupt changes to blood gases in between breaths.
What does FRC do that keeps alveoli healthy?
Holds them open since they don’t have cartilage keeping them open… if we have atelectasis, we have lower FRC
What is ERV?
Respiratory reserve volume, 1.5L
This is the air you breathe out when you forcefully exhale beyond standard. Removable air.
What is RV?
Residual volume
This is not removable, this is what’s in lungs after you force everything out as much as possible. Also 1.5L
What percentage of your TLC can you forcefully breathe out?
75%
What is IRV?
Inspiratory reserve volume, 2.5L
Amount of extra air we can breathe in above normal VT
e.g. we breathe in 500mL, but then take a full huge breath to hit 3000mL total
Vital capacity
Maximum working value of the lungs, which means if we used inspiratory capacity (3L), and then exhaled that + our ERV (1.5L) for a total of 4.5L
Maximum effort on both sides.
How does body position change volume of air in the lungs?
If we lay down on our back, our diaphragm pushes on our lungs, pushing out part of our ERV.
This is why sitting someone up in bed helps them breathe, you’re taking diaphragmatic pressure off the lungs.
Normal breathing cycle
2 seconds in, 2 seconds out, 1 second in between breaths… 5 seconds total.
Normal respiratory rate
12bpm
What is their BPM if their breathing cycle is 3 seconds total? (1+1+1)
20
(60 seconds divided by 3)
What is our intrapleural pressure in between breaths?
-5cmH2O
At peak inspiration, what’s the intrapleural pressure?
-7.5cmH2O
The difference from -5 to -7.5 is what pulls in our tidal volume
What second mark does inspiratory flow peak?
1 second
Air flow rate
Measured in L/s, it’s how fast the air is moving.
Peak speed for air flow is
0.5 L/s at 1 second mark of breathing cycle.
Negative -L/s means airflow is moving
in
What is PIP
Intrapleural pressure
At 0 second mark, the pressure inside the alveoli is ____ while intrapleural pressure is _____
0 cmH2O at SEA LEVEL; -5 cmH2O
What happens with the alveoli at the 1 second mark? Intraplueral?
Gas pressure is lowest at -1cmH2O at peak inspiration speed, while the intrapleural is between -5 and -7.5cmH2O
What is the pressure of alveoli at the 2 second mark?
End of inspiration, back to 0 because air has now entered the alveoli. Intrapleural pressure is now the lowest at -7.5cmH2O
What happens to alveoli once the diaphragm relaxes and air is exhaled?
Pressure inside alveoli becomes positive, forcing air out until it gets back to 0 cmH2O and -5 cmH2O intrapleurally.
What decides which direction the air moves?
Delta P.
When it’s negative, moves into alveoli, when it’s positive, out of alveoli.
What helps push the air back out when the diaphragm relaxes?
Elastic recoil of alveoli.
Without recoil, becomes much more difficult to expire air.
Difference between PIP and PPl
PIP is intrapleural while PPl is just pleural (?)
Transpulmonary pressure
PTP, a difference in pressures between two sides of a wall.
e.g. pleural vs alveolar pressure is +5 difference
Another name for trans pulmonary pressure
Transmural pressure
Why is trans pulmonary pressure important?
Pressure used to fill lungs with air.. increasing this difference will fill the lungs, and it’s highly dependent on pleural pressure.
What is blood flow through lungs dependent upon?
Gravity
West perfusion zones have how many?
4 according to west
3 according to levitszky
Which zone is sometimes on, sometimes off?
Zone 2
What is the order of pressures in zone 2?
Pa > PA > PV
Arterial pressure is higher than alveolar, which is higher than venous.
Vascular pressures in the lung will be higher in the
lower portion of the lung (zone 3)
What is blood flow of zone 2 dependent upon?
pulmonary blood pressure
if its low, less likely to have flow.
What do you need in order to have blood flow in a specific area of the lung?
Blood pressure to be higher than alveolar pressure.
When does zone 3 have blood flow?
All the time
What’s the pressure order of zone 3?
Pa > PV > PA
Higher pressure in the lungs means what for those vessels?
They’re very compliant, so the extra pressure causes them to be larger and wider.
Higher pulmonary blood pressure means what for resistance to perfusion?
Less resistance to perfusion, more blood flow.
Zone 1 exists when
only in unhealthy people and PPV
What is the pressure order of zone 1?
PA > Pa > PV
What does it mean for blood flow if alveolar pressure is higher than the Pa and PV?
blood won’t flow because the compliant vessels are collapsed.
Main thing that gives zone 1 blood flow is
PPV
Zone 4
Very bottom of lung, where the lung rests on the diaphragm. Has slightly less blood flow than bottom of zone 3 due to the compression from the lung sitting on the diaphragm.
