Ventilation 10/10

Front 1

Ventilation is defined as

Back 1

The process that exchanges gases between the external environment and the alveoli

Front 2

Ventilation is a mechanism of ________ ________elimination from the alveoli

Back 2

Carbon dioxide

Front 3

Ventilation is a mechanism of _________ delivery and ________ at the alveoli

Back 3

Oxygen, diffusion

Front 4

What is driving pressure

Back 4

The pressure difference between two points in a tube or vessel

And

The force required to move gas or fluid through a tube or vessel

Front 5

Ventilation occurs in the lungs due to ________ _________ created by thoracic expansion and contraction

Back 5

Pressure differences

Front 6

Positive driving pressure refers to

Back 6

Pressure > atmospheric

Front 7

Negative driving pressure refers to

Back 7

Pressure < atmospheric

Front 8

transairway pressure is the

Back 8

Pressure difference between the mouth and the alveoli

Front 9

Transairway pressure represents the driving pressure required to

Back 9

Force the air in and out of the lungs

Front 10

Pta=

Back 10

Pta= Pm-Palv

Front 11

transpulmonary pressure is the difference between the

Back 11

Alveolar pressure and the pleural pressure

Front 12

Transpulmonary pressure maintains

Back 12

Alveolar inflation at resting volume

Front 13

Pleural pressure is always ____ than atmospheric pressure

Back 13

Less

Front 14

Ptp=

Back 14

Ptp=Palv-Ppl

Front 15

transthoracic pressure is the difference between the

Back 15

Alveolar pressure and the body surface pressure

Front 16

Transthoracic pressure represents the total pressure necessary to

Back 16

Expand or contract the lungs and the chest wall

Front 17

Transthoracic pressure is technically the same as

Back 17

Transairway pressure

Front 18

Ptt=

Back 18

Ptt=Palv-Pbs

Front 19

Gas flow into the lungs is caused by these two pressure changes

Back 19

Transairway and transpulmonary

Front 20

Transairway and transpulmonary pressure occurs in response to

Back 20

The action of the diaphragm

Front 21

The diaphragm contracting and moving downward causes the

Back 21

Thoracic volume to increase and intra alveolar and intra pleural pressures to decrease

Front 22

End inspiration is

Back 22

When equilibrium is achieved between intra alveolar pressures and barometric pressures

Front 23

When end inspiration has been achieved the

Back 23

Downward movement of the diaphragm stops

Front 24

During exhalation the

Back 24

Thoracic volume decreases and intra alveolar and intra pleural pressures increase

(> atmospheric)

Front 25

End expiration is

Back 25

When intra alveolar pressure and barometric pressure are in equilibrium

Front 26

At rest the normal diaphragmatic excursion is about

Back 26

1.5cm

Front 27

The 1.5cm movement if the diaphragm results in intrapleural pressure change of about

Back 27

3-6cm H2O

Front 28

During deep inspiration the diaphragm may move as much as

Back 28

6-10cm

Front 29

During deep inspiration intrapleural pressures may drop to

Back 29

50 cm H2O below barometric pressure

Front 30

In positive pressure ventilation, intra alveolar and intrapleural pressures

Back 30

Increases above atmospheric

Front 31

In positive pressure ventilation the diaphragm is

Back 31

Pushed downwards until set volume or pressure is met

Front 32

During positive pressure ventilation, expiration the intra alveolar and intrapleural pressure

Back 32

Decreases toward barometric pressure

Front 33

Static is defined as

Back 33

The study of matter at rest and the forces restoring in or maintaining equilibrium

Front 34

The lungs natural tendency is to

Back 34

Recoil inward (collapse)

Front 35

The chest walls natural tendency is to

Back 35

Move outward (expand)

Front 36

When at equilibrium lungs are at their

Back 36

Resting volume or functional residual capacity (what's left over)

Front 37

The static forces of the lungs cause an inflated lung to

Back 37

Recoil inward

the elastic properties of lung tissue and the surface tension produced by fluid later inside alveoli

Front 38

(transairway pressure inhale)

Pm=

Back 38

pressure of the mouth = 760 mmHg

Front 39

(transairway pressure inhale)

Palv=

Back 39

pressure of the alveoli = 757 mmHg

Front 40

transairway pressure difference

Back 40

+/- 3 mmHg

Front 41

transairway pressure exhalation

Pm=

Back 41

Pm= 760 mmHg

Front 42

transairway pressure exhalation

Palv=

Back 42

Palv = 763 mmHg

Front 43

Elastance is the natural ability of matter to respond

Back 43

Directly to a force and to return to its original resting position or shape once force is withdrawn

Front 44

Elastance is a measure of the tendency of a

Back 44

Hollow organ to recoil towards its original dimensions upon removal of a distending or compressing force

Front 45

Elastance equation

Back 45

Elastance = change of pressure/change of volume

Front 46

Hookes law states that when a spring is acted on by one unit of force the spring will stretch

Back 46

One unit if strength

Front 47

If the elastic limit of the spring is exceeded the ability of length to increase

Back 47

Ceases

Front 48

Lung compliance is how readily the elastic forces of the lungs

Back 48

Accepts a volume of inspired air (CL)

Front 49

Lung compliance is the change in

Back 49

Lung volume per unit pressure change

Front 50

Lung compliance equation

Back 50

CL= change in volume/change in pressure

Front 51

Normal adult value of lung compliance

Back 51

0.1 L/cmH2O

Front 52

Increased lung compliance means

Back 52

Lungs will accept a greater volume if gas per unit of pressure change

Front 53

Decreased lung compliance

Back 53

Lungs accept a smaller volume of gas per unit of pressure change

Front 54

Hysteresis is the

Back 54

Physical manifestation lagging behind the force

Front 55

Hysteresis exhibited by there lung is a result of

Back 55

Surface tensions of the alveoli

Front 56

Surface tension is measured in

Back 56

Dynes/cm

Front 57

What is the force necessary to cause a tear 1 cm long in the surface layer of a liquid?

Back 57

1 dyne/cm

Front 58

Alveolar fluid has the potential to exert a surface tension force in excess of

Back 58

70 dynes/cm

Front 59

Alveolar fluid's potential surface tension force can easily cause

Back 59

alveolar collapse

Front 60

Laplace's law describes how the distending pressure of a liquid bubble (not an alveolus) is influenced by (2)

Back 60

surface tension of the bubble

the size of the bubble itself

Front 61

In Laplace's law, as surface tension of a liquid bubble increases, distending pressure must

Back 61

also increase to keep the bubble open

Front 62

In Laplace's law,as the radius of a bubble increases, distending pressure to keep the bubble open

Back 62

decreases (blowing up a balloon)

Front 63

In Laplace's law,when two different size bubbles (with the same surface tension) are in direct communication the greater pressure of the _______ bubble will empty into the ______ bubble.

Back 63

smaller, larger

Front 64

During the formation of a new bubble, Laplace's principles do not apply until

Back 64

distending pressure of the liquid sphere goes beyond the critical opening pressure

Front 65

The critical opening pressure is the high pressure required to

Back 65

overcome surface tension forces during bubble formation

Front 66

Once critical opening pressure has been met, distending pressure decreases as what increases

Back 66

radius size

Front 67

As the radius of the bubble decreases, distending pressure _______ until it reaches its ______ ________ ________.

Back 67

increases, critical closing pressure

Front 68

The critical closing pressure is the same as

Back 68

the critical opening pressure

Front 69

In Laplace's law, when the molecular forces of the bubble become greater than the distending pressure the bubble

Back 69

collapses

Front 70

In Laplace's law, the size of the bubble does not vary the

Back 70

surface tension

Front 71

According to Laplace's law, high transpulmonary pressure would be required to maintain

Back 71

patency (ability to stay open) of the small alveoli

Front 72

What offsets the surface tension forces of alveolar fluid in the healthy lung?

Back 72

pulmonary surfactant

Front 73

90% of surfactant is composed of

Back 73

phospholipids

Front 74

10% of surfactant is

Back 74

proteins

Front 75

The primary active phospholipid in surfactant is

Back 75

DPPC (dipalmitoyl phosphatidylcholine)

Front 76

The DPPC molecule causes surface tension to decrease with

Back 76

decreased alveolar size

Front 77

The DPPC molecule causes surface tension to increase with

Back 77

increased alveolar size

Front 78

Surface tension in the average small alveoli is

Back 78

about 5-15 dynes/cm

Front 79

Surface tension in the average fully distended alveoli is

Back 79

about 50 dynes/cm

Front 80

Surface tension forces within the alveoli would be greater than the critical closing pressure without what?

Back 80

surfactant

Front 81

If complete alveolar collapse occurred what else would occur?

Back 81

atelectasis

Front 82

What are the 7 functions of surfactant?

Back 82

decrease inflation pressure

improve lung compliance

provides alveolar stability

decreases work of breathing

enhances alveolar fluid clearance

enhances foreign particle clearance

serves as protective layer for cell surface