Pulmonary Ventilation Flashcards Preview

A. White- Human Physiology > Pulmonary Ventilation > Flashcards

Flashcards in Pulmonary Ventilation Deck (42):
1

What muscles are expiratory?

abdominal muscles

Internal intercostalis

2

What is total lung capacity?

The maximum volume of gas the lungs can hold.

3

What are lung volumes?

distinct, non-overlapping sub-compartments that make up the total lung capacity.

4

What is tidal volume?

volume of air that is inspired or expired with each breath at rest.

500 mL

5

What is inspiratory reserve volume?

volume of air that can be inspired in addition to tidal volume with forceful inspiration.

3000 mL.

6

What is expiratory reserve volume?

Additional volume of air that can be expired at end of tidal volume by forceful expiration.

1100 mL

7

What is residual volume?

Volume of air remaining in lungs after forceful expiration.

8

What is vital capacity?

The sum of all the volumes that can be inspired or exhaled (inspiration to the maximum extent plus expiration to the maximum extent).

4600 mL

9

What is total lung capacity?

The sum of all the volumes of air. It is vital capacity plus residual volume.

5800 mL

10

What is inspiratory capacity?

The sum of all volumes above resting capacity. It is the tidal volume plus inspiratory reserve volume.

3500 mL.

11

What is the functional residual capacity?

The sum of volumes below resting capacity. It is expiratory reserve volume + residual volume.

2300 mL

12

What is minute ventilation?

Total volume of gases moved into or out of the lungs per minute.

= (breaths per minute) x (tidal volume)

13

What is alveolar ventilation?

Total voume of gases that enter spaces participating in gas exchange per minute.

= (breaths per minute) x (Tidal volume - dead space)

14

Where is the anatomic dead space?

trachea, bronchi, bronchioles

15

What is the physiological dead space?

anatomic dead space + ventilated alveoli with poor or absent perfusion.

16

What is the total dead space in a normal individual?

.15 L

17

What is the tidal volume in a normal individual?

0.5 L.

18

What is minute ventilation?

0.5 x breathing rate

19

What is alveolar ventilation?

0.35 x breathing rate

(tidal volume - dead space) x breathing rate

20

What are two observations about dead space?

It does not participate in ventilation and contains neglibile CO2.

Amount of CO2 in regions of lungs involved in gas exchange = that of arterial blood (PaCO2).

21

Why does the amount of carbon dioxide originating from regions of the lungs equal that of arterial blood?

Blood gases equilibrate with alveolar gases during transit through the pulmonary circulation.

22

What is the formula for dead space?

Vd = Vtot x (PaCO2 - PeCO2)/PaCO2

23

What is pleural pressure?

Pressure of the fluid between parietal pleura and the visceral pleura.

24

What is alveolar pressure?

Pressure of the air inside the alveoli.

25

What is transpulmonary pressure?

Difference between the alveolar pressure and pleural pressure.

26

How is transpulmonary pressure calculated?

Difference in pressure between pleural and alveolar pressures during any point in the inspiration or expiration cycle.

27

What is the definition of compliance?

The extent to which the lungs will expand for each unit increase in the transpulmonary pressure.

28

What is alveolar pressure?

pressure of the air inside the alveoli

29

What is pleural pressure?

The pressure of the fluid in the space between the plerural and parietal pleura.

30

What is the relationship between compliance and elastance?

Compliance and elastance are inversely proportional.

31

How is pressure related to alveolar surface tension?

In the absence of surface tension, pressure changes slightly and the lungs can be expanded.

32

How is pressure related to the alveolar radius?

Negative pressure increases the alveolar radius.

33

Why does a lung filled with saline expand easier than a lung filled with air?

There is less surface tension in the saline-filled lung.

34

What is the formula for compliance?

increase in volume/increase in pressure

35

What is surfactant produced by?

type II alveolar clls.

36

What happens if air passages leading from the alveoli are blocked, what happens?

The surface tension in the alveoli collapses the alveoli.

This creates positive pressure in the alveoli.

37

What is the pressure in the alveoli?

Pressure = 2 x surface tension / radius of alveolus

38

What would happen if there were no surfactant?

The pressure would calculate to about 18 cm of water pressure; about 4.5 times as great.

39

What muscles are inspiratory?

Respiratory diaphragm

External intercostal muscles

Sternomasatoids

Serratus anterior muscles

Scalene muscles

40

What muscles are inspiratory muscles?

> diaphragm
> external intercostal muscles (limited)
> sternomastoids
> serratus anterior muscles
> scales muscles

41

The combination of lung volumes form what?

> they form lung capacities

42

What is the formula for alveolar ventilation?

(Breaths per minute) x ( Tidal volume - Dead space)