Pulmonary Anatomy and Physiology ppt Flashcards Preview

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1
Q

Just a quick reveiw of some anatomy, he said it is just info but I thought it would be good to know your BASIC anatomy prior to becoming a lung master!!!!

what makes up the thoracic cage?

what is the thoracic cage for?

A

-12 thoracic vertebral bodies, the ribs, and the sternum

protection and pliability

2
Q

Just a quick reveiw of some anatomy, he said it is just info but I thought it would be good to know your BASIC anatomy prior to becoming a lung master!!!!

  1. what is a useful landmark b/c it corresponds to the mid portion of the trachea? (which as we all know is the desirable location for the distal tip of the tracheal tube)
  2. the trachea is fibromuscular. how long is it? and what is it’s diameter?
  3. the trachea beagins at what vertebra?
  4. it bifurcates where? (name and location)
  5. the right main stem bronchus extends approx ____cm before it’s initial division into the bronchus to the right, upper and missle lobes?
  6. The left mainstem bronchus extends approx ____ cm before its initial division.
  7. 1/250-1/50 people have and anomalous what?
A
  1. the 2nd thoracic vertebra
  2. 10-12 cm long, 20 mm diameter
  3. 6th cervical vertebra
  4. at the carina, 5th thoracic vertebra
  5. 2.3 cm
  6. 5 cm
  7. RUL bronchus above the carina
3
Q

what degree do the bronchus take off at?

right?

left?

A

right-250

left- 450

4
Q

do the bronchioles have cartilage like the bronchi??

A

no that would be silly

5
Q

The “air” transfers from the bronchi to the bronchioles then divide to transitional resp bronchioles. during all of this what happens to caliber and total airway area?

A

the caliber decreases and the total airway area increases!

(sounds confusing but this is what i found when I looked it up…so basicaly we are going from a Large diameter (caliber) bronchi to the smaller bronchioles. althought the diameter or caliber gets smaller teh actual surface area is larger, b/c there are more bronchials kind of like the alveoli have a huge surface area dispite being smaller than a freckel on an ants pecker)

6
Q

what is between the visceral and parietal pleura and why?

A

a thin layer of fluid to allow the lungs to move in a smooth motion

(visceral is toward the organ (lung) and the parietal pleura is toward the rib cage)

7
Q

what occurs with negative pressure in the lungs?

A

the lungs expand and the layers are approximated

8
Q

Note position of lungs

anterior

A
9
Q

Note position of lungs

right side

A
10
Q

Note position of lungs

left side

A
11
Q

As stated previously notice the different bronchi and see the 250 right vs the 450 left and the cm difference between the first branches

A
12
Q

****************************

what do we do if a pt gets over constriction? like an analphalaxis response or a recative airway?

A

we either want to OVERDRIVE the sympathetic side (our beta agonist) or give epinephrine

or we want to KNOCK OUT the parasympathetic side- atropine, glycopyrrolate, atrovent (anticholinergics)

side note- the reason we do this is because this is b/c when they are having a airway issuse that is causing the lungs to constrict is it PNS not SNS so we need to stop it or overcome it

13
Q

*******************************

as the last slide stated if we are having a constrictive airway problem we are having a PNS response. This slide will tie in with it and show why the smooth muscle is PNS controlled

So what are the 4 ways that airway smooth muscle is controlled (basically what controlls the resistance in the airway smooth muscle)

A
  1. Humeral and neural influances
  2. Rich PARASYMPATHETIC innervation (ACh)
  3. ß2 receptors- smaller airways
  4. NANC receptors (NonAdrenergic NonCholinergic)- histamine H1 and H2, substance P
14
Q
  1. Increases in lung volumes are accompanied by increases in what?
  2. As lung volumes decrease below FRC significant increases in what occurs?
A
  1. airway diameter

B/c the airways are tethered by the surrunding lung parenchyma.

   2.  airway resistance
15
Q

pharmacological blockade of the PNS pathways or surgical transection of the vagus nerves can cause what in the lungs?

A

bronchodilation

(remember what i said earlier, to overcome the airway resistance you must increase SNS or block PNS)

16
Q

the NANC stimulation of the airway smooth muscle realeases H1 and H2. what do each do? and which one prevales?

A

H1 receptors -bronchoconstriction

H2 receptors- Bronchodilation

but regardless the predominant effect is bronchoconstriction

17
Q

Inhaled gases are warmed, filtered and humidified by what?

A

the nasal vascular mucosa (your god damn nose)

18
Q

the nose can heat the filtered air within __0C of body temp.

(i found this kinda of crazy. the nose is kind of like an instant warmer)

A

10C

33.8oF

19
Q

The nose humidifies the air to almost _____%

A

100%

20
Q

What in the nose is for mucous and particle removal?

A

Nasal cilia

21
Q

what can supress the cough reflex? and what can this lead to?

A

the administration of

general anesthesia

local anesthesia to the airway

opiods

benzodiazepines

-leads to the impaired clearance of secretions and foreign material from the airway

22
Q

the cough reflex is mediated by what? and from where? so it is controlled by what part of the ANS?

A

vagus mediated

from the medulla

PNS

23
Q

What actually occurs with a cough? or the basic 3 steps in a cough reaction

A

deep inspiration ⇒ glottic closure ⇒ forceful expiration (a cough0

24
Q

the Sneeze relex (or nose cough as I like to call it) is similar to a cough with what exception!!!

this is a gimme come on you know it!!!

A

it facilitates the clearance of secretions from the nasal passageway, rather than the passageway below the nose

25
Q

***********************************

what is the chief muscle of breathing?

A

The diaphragm

26
Q

******************************

the diaphragm accounts for approximately __% of the air that enters the lungs during spontaneous inspiration.

A

75%

27
Q

how does the diaphragm cause gas to flow into the chest?

A

by decreasing intrathoracic pressure to less than atmospheric pressure

28
Q

***************

the diaphragm does what to abdominal contents during inspiration?

A

downward and forward

29
Q

************************

what is the usual (average/normal) diaphragm excursion?

A

1-10cm

30
Q

*********************

what in the spinal cord is the diaphragm controlled? and by what nerve?

A

cervical roots 3-5

the phrenic nerve

** a way to remember 3,4,5 keeps the lungs alive**

31
Q

*************************

some defining characteristics of the diaphragm

what type of nerves?

in controlled by what part of the cell?

rich in what?

and is vascularity?

A

what type of nerves? slow twitch

in controlled by what part of the cell? mitochondria

rich in what? myoglobin

and is vascularity? highly vascular

32
Q

***********************

what do the external intercostals do?

A

contract to assist with inspiration

(a small amout)

**how to remember EXternal INspiration

INternal EXperation

EX-IN

IN-EX

33
Q

***********************

What do the internal intercostals do?

A

the Tension (he uses this word and not the word contraction frther explanation will follow) allows retraction during exhalation

—the book states (this is why i think the word tension is more important than contraction) normal exhalation is a passive event utilizing the elastic recoil of the lungs, chest wall, and abdominal structures.

**how to remember EXternal INspiration

INternal EXperation

EX-IN

IN-EX

34
Q

*********************

Inhalation is chiefly a result of what??? but there is some _______ intercostals as well.

A

Diaphragm

external

35
Q

******************

inhalation provides what type of tension??

and to what organs/tissue??

A

ACTIVE

to the thoracic and lung tissue

** i didn’t know exactly what this “active” tension was so here it is-

Active tension– derives from the interaction between myosin and actin active tension.

Passive tension– can develop in the muscle’s complex connective tissue.

36
Q

**********************

what is the normal resting tension in the lungs??

what is the MAX INSPIRATION tension?

A

* Normal* -4 mmHg

** Max** > -12 mmHg

37
Q

**************************

exhalation is primary passive. Why is this?

A

bc exhalation results from a recoil of tension

38
Q

********************

An important additional exhalation mechanism (deflating force) is the surface tension of the fluid lining in the alveoli what are the 2 parts that cause this and what is the ratio of the parts to that allow this to occur?

A

Lung elastic fibers 1/3

surface tension/surfactant 2/3

I know this is real confusing but he said it was important on page 900 of S&H and ppt slide 13 may be some (but trust me) very little further assistance

39
Q

******************

what are the most important muscles for forced exhalation or exhaltion during exertion (either way you want to look at it)

A

Abdominal muscles

40
Q

What law describes surface tension properties mathmatically?

A

Laplace’s law

41
Q

What does laplace’s law state? and give an example

A
  1. The pressure to expand is directly proportional to tension/radius
  2. ex. the pressure inside the bubble (alveoli) necessary to keep it expanded is directly proportional to the tension on the wall of the bubble (which tends to collapse it) divided by the radius of the bubble.
42
Q

What results from the attraction between the molecules of the fluid film that lines the alveoli (tends to reduce the alveolar diameter)

A

surface tension

43
Q

What helps to stabilize the sizes of the alveoli, reducing the surface tension in the larger alveoli to a lesser extent than in smaller alveoli? The net effect is maintenance of consistent alveolar diameter and stability

A

pulmonary surfactant

44
Q

Surface tension is greater when fluid molecules are what?

A

closer together

b/c remember the definition of surface tension is–

What results from the attraction between the molecules of the fluid film that lines the alveoli (tends to reduce the alveolar diameter)

45
Q

*****************

when the surface area of the surfactant film is kept small, a rearrangemnt of molecules occurs, causing surface tension to ____1__\_ with time. Therefore, peripheral alveoli tend to *____2____* during prolonged periods of shallow breathing?

so basically smaller and smaller (tidal) volumes equals *____3___*

A
  1. Increase
  2. collapse
  3. Collapse (atelectasis)
46
Q

*****************

when the surface area of the surfactant film is kept small, a rearrangemnt of molecules occurs, causing surface tension to increase** with time. Therefore, peripheral alveoli tend to **collapse during prolonged periods of shallow breathing.

so basically smaller and smaller (tidal) volumes equals Collapse (atelectasis)

since we know know all of this is true!!!! what can WE do immediatly to increase their surface area, thus restoring normal surface tension?? 3 things? and in doing these things what is the main goal of this treatment.

A
  1. A single large breath
  2. Vital capacity maneuver
  3. Sigh

The main goal is to RE-EXPAND these alveoli

47
Q

what promotes fluid movement into the alveolus?

A

the tension

48
Q

Surfactant

  1. Made up of what?
  2. secreted by what?
  3. 1st produced when?
  4. what does it do?
  5. what 3 things make it decrease?
A
  1. Lipoprotein
  2. Pneumocytes
  3. 28-32 wks gestation
  4. decreases surface tension to physiologic levels
  5. -100% O2
          - smokers
          - after CPB (coronary pulmonary bypass)
49
Q

*************

the less the alveoli expand the more they want to do what

A

contract

50
Q

we now know that tension allows fluid movement into the alveoli, but what keeps extra fluid out of the alveoli?

A

colloid osmotic pressure- it keeps the fluid intravascular

51
Q

*****

  1. with mechanical ventilation which alveoli expand more? apical or basal?
  2. with spontaneous breathing which alveoli expand more?
  3. this regional ventilation is all based on ________ in alveolar size?
A
  1. apical alveoli expand > basal
  2. Basal alveoli expand > apical
  3. Change
52
Q

the Basal alveoli has a greater change in size with what type of ventilation

A

spontaneous

(thus apical alveoli has a greater change in size with mechanical ventilation)

53
Q

What is the total amount of gas moved into the lungs in a minute?

(it represents the total amount of gas moved into the lungs each minute)

A

Minute ventilation

54
Q

how do you calculate minute ventilation

A

TV x frequency of breathing

55
Q

the average minute ventilation is what?

A

6 Liters

56
Q

what is more important that MV, But we use minute ventilation instead b/c this is too hard to calculate

A

alveolar ventilation

57
Q

what is alveolar ventilation

A

the volume of gas each minute that enters those areas of the lungs caple of participating in gas exchange with pulmonary capillary blood

58
Q

why is the alveolar ventilation less than MV?

A

b/c a portion of the inhaled gases resides in those areas of the airway (dead space est to be 150ml) that do not participate in gas exchange with pulmonary capillary blood

59
Q

***

Alveolar Ventilation

  1. Is what?
  2. Is less or more than MV?
  3. how is it calculated?
  4. average is what?
  5. What 2 things are determined via the alveolar ventilation?
A
  1. Gas capable of participating in gas exchange
  2. less than MV
  3. TV-dead space x RR
  4. 4.2 L/min
  5. PaCO2 and to a lesser degree PaO2
60
Q

Hypercarbia increases _____ HTN and dilates vessels in the head leading to increased ___

A

pulmonary

ICP

61
Q

2 types of dead space

A
  1. Anatomic
  2. Physiologic
62
Q

what is the anatomic dead space? what is included in it?

A
  • The areas of the respiratory tract that do not normally participate in gas exchange with the pulmonary capillary bed.
  • Includes the
    • nasal passage
    • pharynx
    • trachea
    • bronchi
63
Q

what is Physiologic dead space?

A
  • simple definition
    • non-perfused alveoli
  • More detailed definition
    • the gas volume of the alveoli that are not functional or only partially functional b/c of absent or poor blood flow through corrosponding pulmonary cappilaries (wasted ventilation)
64
Q

what is the average amount of dead space in an adult?

A

2 mL/kg or approximately 150 mL

65
Q

does dead space contain and nitrigen?

A

nope

(i just thought that was odd so I put it here)

66
Q

During exhalation gas in the ______1_______ is exhaled before gas comming from the _____2___\_

A
  1. dead space
  2. alveoli
67
Q

*************

an alveoli that is not ventilated is called a what?

A

Shunt

68
Q

with dead space ventilation what is this and say why??

A

Normal

b/c you have normal perfusion and normal blood flow!!

69
Q

with dead space ventilation what is this and say why??

A

Shunt

b/c No ventilation and normal perfusion

70
Q

with dead space ventilation what is this and say why??

A

Dead Space

b/c normal ventilation but No perfusion

71
Q

with dead space ventilation what is this and say why??

A

Dead Unit

b/c No ventilation and No perfusion

72
Q

Control of ventilation is via what 2 types of control?

A

neural

chemical

73
Q

Ventilation will adjust in response to what 3 things in the body?

A

PaO2

PaCO2

and

H+ ion concentrations

74
Q

*****

the major factor in regulation of alveolar ventilation in the ____1__ rather than the __2___

A
  1. PaCO2
  2. PaO2
75
Q

so we just learned that the major factor in regulation of alveolar ventilation is the PaCO2 rather than the PaO2. the is shown as the following. a 50% increase in PaCO2 evokes a ______ increase in alveolar ventilation, and a PaO2 of 40 mmHg only evoke a ______ increase in alveolar ventilation

A

ten-fold

1.5-fold

76
Q

the FINE control of ventilation is provided by the respiratory center under the influance of chemical stimuli from what???

A

chemoreceptors

77
Q

How does the medullary vasomotor center communicate with the repiratory center to influance ventilation??

2 ways

A
  1. decrease in systemic B/P evoke a SNS activity (from vasomotor center)this causes an increase in alveolar ventilation
  2. Hyperthermia directly and indirectly increases ventilation
78
Q

****

the respiratory center is located bilaterally in the reticular substance of the what?

A

medulla oblongata and pons

79
Q

***

the inspiratory area of the respiratory center does what? For a bonus where is it located?

A

rhythmic (insiratory) cycles

bilat in dorsal portion of medulla

side note it is vagal modulated

80
Q

******

the Pneumotaxic area of the respiratory center does what?

A

determines the duration of the inspiration

(in other words triggers the termination of inspiration)

81
Q

***

when does the apneustic center kick in? what are its characteristics?

A

only works if there is no pneumotaxic area stimulation

the pattern is maximal lung inflation with occasional breif expiratory gaps (apneuses)

82
Q

The inflation and deflation reflexes on ventilation control are controlled by what?

A

vagal stretch receptors

83
Q

***

in regards to the expiratory area of the ventilation controll center.

what is it normally doing?

When does it become active?

A

inactive

with increased alveolar ventilation

84
Q

the chemical control of ventilation adjust respiration to maintain a constant ___1____, to defend against excessive changes in __2__ comcentrations and to prevent a dangerous decrease in ___3___

A
  1. PCO2
  2. H+ ion
  3. PaO2
85
Q

what are the 2 chemoreceptors that regulate the chemical controll of ventilation?

A
  1. medullary chemorecptors
  2. Peripheral chemoreceptors
86
Q

where are the medullary chemoreceptors located

A

a few microns below the medulla (basically in the medulla)

87
Q

*******

the medullary chemorecptors

  1. Most responsive to what?
  2. Why are they most response to that?
  3. How does the CO2 stimulate the chemosensitive area of the medulla?
A
  1. CO2 concentrations
  2. b/c the H+ ions can’t easily cross BBB
  3. CO2 crosses BBB ⇒ mixes with H2O ⇒ forms Carbonic acid (H2CO3) ⇒dissociates into H+ ions (H+ and HCO3)

(this is that whole equation that shores taught us) shadush bitch putting it all together……

88
Q

___ to ___% of the ventilatory response from the medulla is in the response to CO2

A

70-80%

89
Q

the changes of H+ ion concentrations in the CSF occurs within __1____, and is much __2____ in interstitial fluids

A
  1. seconds
  2. slower
90
Q

***

where are the peripheral chemoreceptors located

A

carotid and aortic bodies

91
Q

which peripheral chemoreceptors respond to the hypoxic ventilatory response

A

carotid bodies

92
Q

*******

In the carotid bodies (hypoxic ventilatory response)

  1. hypoxic ventilatory response transmits through what nerve?
  2. it responds to what very rapidly?
  3. this hypoxic ventilatory response is inhibited by what?
A
  1. glossopharyngeal nerve
  2. PaO2 (not SaO2)
  3. VAA
93
Q

Which peripheral chemoreceptor is not ad involved with the ventilatory response?

A

Aortic bodies

94
Q

the peripheral Chemoreceptors that are located in the aortic bodies

  1. transmitt thorugh what nerve?
  2. and is more prominent in what response?
A
  1. vagus
  2. CV response
95
Q

interesting fact

i stated that it is the PaO2 not the SaO2 (arterial hemoglobin saturation) that determines the stimulation level of the peripheral chemoreceptors.

A

this is the reason that anemia or carbon monoxide poisioning, inwhich the amount of dissolved oxygen and the PO2 remains normal, do not stimulate alveolar ventilation via the chemoreceptors.

(just for knowledge)

96
Q

The regulation of pulmonary blood flow is what? but can also can be affected by what?

A

passive

O2 and C02

97
Q

there is a anatural anatomic shunt of what % of CO

A

2-5%

98
Q

what do all the lymphatic vessles do?

A

remove particulate and protein

99
Q

pulmonary b/p is ___ that of systemic b/p

thus is a persons systemic B/P is 100 systolic what would you expect it to be in the pulmonary system

A

1/5

20

100
Q

Normal PAP is what?

normal PAP mean is what?

PAP= Pulmonary Artery Pressure

A

22/8

13

( remember how to calculate MAP)

(dys x 2) + Sys / 3

so

((8 x 2) + 22) /3

16+ 22 = 38

38 / 3= 12.666666 =13

so remember the PAP and you can figure out the MAP

101
Q

PAOP pressure in normally what?

PAOP= pulmonary capillary pressure/ or pulmonary capillary wedge pressure or PCWP (also called the pulmonary wedge pressure or PWP, or pulmonary artery occlusion pressure or PAOP

A

10 mmHg

102
Q

what is the mean pressure in the pulm veins?

A

4 mmHg

103
Q

the resistance to blood flow in the pulmonary circulation is about ______ the resistance in systemic circulation

A

1/10th

104
Q

how do you estimate the LAP?

A

usually the PAOP is 2-3 mmHg higher than the LAP

105
Q

what can increase LAP??

A

anything that is distal to the LA

for example mitrsl stenois

LVH

Increased SVR

Mitral Regurg

Aortic Stenosis

Aortic regurg

106
Q

WHat is higer LAP or RAP

A

LAP

107
Q

Pulmonary blood flow is greatest where? give examples

A

in dependent areas

posterior lungs (when supine)

bases (when standing)

108
Q

Optimal oxygenation requires what?

A

V/Q matching

109
Q

what is perfusion with suboptimal ventilation

A

shunt

110
Q

What is ventilation with suboptimal perfusion?

A

dead space

111
Q

Suboptimal ventilation and perfusion equals what?

A

dead unit

112
Q

****

what evokes Hypoxic Pulmonary Vasoconstriction?

give the actuall numbers also

A

alveolar hypoxia

which is a PaO2 < 70 mmHg

113
Q

******

what is HPV

A

when alveolar hypoxia (PaO2 <70 mmHg)is sensned it evokes vasoconstriction in the pulmonary arterioles supplying the affected alveoli; the net effect is diverted blow flow away from the poorly ventilated alveoli, as a result the shunt is minimized, and the resting PaO2 is maximized

114
Q

A PaO2 of what evokes HPV?

A

<70 mmHg

115
Q

what is uniqe about HPV and how is occurs???

A

it is locally mediated!

this means that it can occur in denervated lungs

so basically even if you have a lung transplant you still get this response.

(i think thats pretty badass)

116
Q

HPV is inhibited by what?

A

VAA (in animal models)

vasodilators

117
Q

******

what is normal VQ mismatch?

and how is that determined??

what is it’s connection to PaO2

what does the formula ?/? mean

A

0.8

vent over perfusion is 4/5 or 0.8

normal Room Air PaO2 80-100

the 4 is smaller than the 5 and it means that of whats getting through 4/5ths is actually getting the oxygen

118
Q

Explain what this means!!

A

Shunt

normal V/Q is 4/5 or 0.8

with a shunt the ventilation is lowered and perfusion remains good. think of it as if u had 0 ventilation and still good perfusion

0/5=0

(that is the example he gave in class just know that with a shunt the V/Q= 0 (or less than 0.8)

so if the VQ mismatch decreases you have a shunt!!!

119
Q

explain what this means

A

Dead space!!

this is because with dead space you have ventilation but the perfusion decreases. so as perfusion decreases you have an infinity (this is again what he states in class)

so if normal V/Q is 4/5=0.8 then deadspace had an infinity

ex V=4 and Q= 0.5

4 / 0.5 = 8

so if the VQ mismatch goes up you have deadspace i

120
Q

with V/Q ventilation is closely matched to what?

A

perfusion

121
Q

3 main causes of a shunt

A

physiologic shunt

hypoventilation

disease states

122
Q

with spontaneous ventilation

what part of the lungs are already maximally distended from greater NEGATIVE pleural pressure?

what does this mean

A

Apex alveoli

less ability to expand and receive volume increases

123
Q

with spontaneous ventilation

what part of the lungs get the greatest gas flow due to greater change in thoracic pressures?

A

the basal alveoli

due to the diaphragmatic downward movement

124
Q

******************************

with spontaneous ventilation

There is a greater ______ ________ in the apex during end expiration and small changes during inspiration

A

Negative pressure

think of it as everything is pulling it down (in a standing position) so a greater negative pressure

125
Q

*******************************

in what zone (zone of west) is the primary normal ventilation occurs ( where there is the lease VQ mismatch)

A

zone 3

126
Q

why does positive pressure ventilation cause VQ mismatch?

A

B/C we end up ventilating the wrong zone. during mechanincal vent we have greasted blood flow to the dependent areas and bases, but the greatest gas flow is to the bases.

127
Q

***********

explain the 3 ZONES of WEST and what they mean

A
  1. PA > Pa > PV =Alveoli pressure is greatest it is greater than arterial and venous pressures. these alveolies are hyperinflated
  2. Pa > PA > PV = arterial pressure greatest
  3. Pa > PV > PA = Pulmonary artery pressure greatest with the least pressure in the alveoli allowing easy gas exchange ( so there is nothing pushing it back, good arterial pressure, good flow, the lung ISN’T over inflated this is ideal)
128
Q

***************

explain Zone 1

“1st draw a picture”

A

Alveolar pressure exceeds arterial exceeds venous

129
Q

***************

explain Zone 2

“1st draw a picture”

A

Arterial pressure exceeds Alveolar exceeds venous

130
Q

***************

explain Zone 3

“1st draw a picture”

A

Arterial pressure exceeds venous exceeds alveolar

in teh supine position its all zone 3

131
Q

When in the supine position what zone are you using the most?

A

3

132
Q

With mechanical ventilation the greatest blood flow is to where?

A

bases

133
Q

with mechanical ventilation the greatest gas flow is to what part of the lungs

A

Apexes

134
Q

*********************************

VQ is poorly matched in mechanically ventilated patients! why is this???

A

Positive pressure ventilation pushesgas into the apexes (path of least resistance), but blood perfuses primarily to the dependent parts of the lung

thank you gravity

135
Q

***********************************

what is a problem with mechanical ventialation??

specifically r/t to the poorly ventilated alveoli (in the bases)

A

poorly ventilated alveoli are prone to atelectasis and collapse

136
Q

whos law deals with partial pressures?

A

daltons law

137
Q

Daltons law of partial pressures for

N2O 79%

O2 21 %

A
138
Q

what is the vapor pressure of water at 370C

A

47 mmHg

139
Q

What si alveolar partial pressure?

what is the alveolar partial pressure for PAO2

and PAN2O

A

you must subtract H2O, add for CO2 and account for O2 abs

PAO2 104mmHg

PAN2O 569 mmHg

140
Q

******************

what is normal PAO2 use (or use of O2)

A

250 mL/min

141
Q

***********

what is teh normal PACO2 delivery

A

200 mL/min

142
Q

CO2 is how many times as diffusible as O2

A

20x’s

143
Q

O2 is how many more times as diffusable as N2O

A

2 x’s

144
Q

explain the last 2 cards on diffusion

A

even though the CO2 gradient is low it is more diffusable so that was you can still have diffusion with a low gradient

O2 diffusion due to large gradients.

CO2 difusses with small gradients

145
Q

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what % of O2 is bound to hemoglobin?

A

97%

146
Q

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what % of O2 is dissolved in plasma???

A

3%

(remember 97% is bound to hgb)

147
Q

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a single Hgb holds how many O2 molecules?

A

4

148
Q

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1 Gram of Hgb will hold how much O2

A

1.34 mL of O2

149
Q

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if you have a Hgb of 15 g/dl how much O2 is being carried? and how did you get this answers?

A

20 mL

1 g of Hgb holds 1.34 mL of O2

so 15 x 1.34 = 20 mL/O2

150
Q

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what is the formula for oxygen content ???

what is the equation for oxygen deliver??

A

Content: (1.34 x Hgb x SaO2) + (0.003 x PaO2)

Delivery: CONTENT x Cardiac Output

151
Q

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what is the normal Aveolar (A) to arterial (a) O2 Gradient

A

5-10 mmHg

152
Q

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how do we calculate the O2 Difference

A

PAO2 - PaO2

153
Q

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How do we Calculate the ideal ALVEOLAR gas equation?

(how do we determine what the PAO2 (A) is so we can calculate the (A-a) O2 difference?)

A

PAO2= FiO2 (PBP - PH20) -PaCO2 / RQ

FIO2= inspired O2 (.21)

PBP = Barometric pressure (760 mmHg)

PH2O= Water vapor (47 mmHg)

RQ = Respiratory Quotient (0.8)

154
Q

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with the A-a O2 Difference what are good numbers

A

single digits

155
Q

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with the Alveolar gas equation how do you calculate RQ

A

PaCO2 / PaO2

normal 0.8

under ventilation 0.7 usually

156
Q

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caculate the A-a O2 gradient. What is the R? is it normal? would O2 help?

PaO2=54

PaCO2 =32

A