Pulmonary Ventilation

Question 1

What muscles are expiratory?

Answer 1

abdominal muscles

Internal intercostalis

Question 2

What is total lung capacity?

Answer 2

The maximum volume of gas the lungs can hold.

Question 3

What are lung volumes?

Answer 3

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

Question 4

What is tidal volume?

Answer 4

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

500 mL

Question 5

What is inspiratory reserve volume?

Answer 5

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

3000 mL.

Question 6

What is expiratory reserve volume?

Answer 6

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

1100 mL

Question 7

What is residual volume?

Answer 7

Volume of air remaining in lungs after forceful expiration.

Question 8

What is vital capacity?

Answer 8

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

Question 9

What is total lung capacity?

Answer 9

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

5800 mL

Question 10

What is inspiratory capacity?

Answer 10

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

3500 mL.

Question 11

What is the functional residual capacity?

Answer 11

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

2300 mL

Question 12

What is minute ventilation?

Answer 12

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

= (breaths per minute) x (tidal volume)

Question 13

What is alveolar ventilation?

Answer 13

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

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

Question 14

Where is the anatomic dead space?

Answer 14

trachea, bronchi, bronchioles

Question 15

What is the physiological dead space?

Answer 15

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

Question 16

What is the total dead space in a normal individual?

Answer 16

.15 L

Question 17

What is the tidal volume in a normal individual?

Answer 17

0.5 L.

Question 18

What is minute ventilation?

Answer 18

0.5 x breathing rate

Question 19

What is alveolar ventilation?

Answer 19

0.35 x breathing rate

(tidal volume - dead space) x breathing rate

Question 20

What are two observations about dead space?

Answer 20

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).

Question 21

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

Answer 21

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

Question 22

What is the formula for dead space?

Answer 22

Vd = Vtot x (PaCO2 - PeCO2)/PaCO2

Question 23

What is pleural pressure?

Answer 23

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

Question 24

What is alveolar pressure?

Answer 24

Pressure of the air inside the alveoli.

Question 25

What is transpulmonary pressure?

Answer 25

Difference between the alveolar pressure and pleural pressure.

Question 26

How is transpulmonary pressure calculated?

Answer 26

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

Question 27

What is the definition of compliance?

Answer 27

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

Question 28

What is alveolar pressure?

Answer 28

pressure of the air inside the alveoli

Question 29

What is pleural pressure?

Answer 29

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

Question 30

What is the relationship between compliance and elastance?

Answer 30

Compliance and elastance are inversely proportional.

Question 31

How is pressure related to alveolar surface tension?

Answer 31

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

Question 32

How is pressure related to the alveolar radius?

Answer 32

Negative pressure increases the alveolar radius.

Question 33

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

Answer 33

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

Question 34

What is the formula for compliance?

Answer 34

increase in volume/increase in pressure

Question 35

What is surfactant produced by?

Answer 35

type II alveolar clls.

Question 36

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

Answer 36

The surface tension in the alveoli collapses the alveoli. This creates positive pressure in the alveoli.

Question 37

What is the pressure in the alveoli?

Answer 37

Pressure = 2 x surface tension / radius of alveolus

Question 38

What would happen if there were no surfactant?

Answer 38

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

Question 39

What muscles are inspiratory?

Answer 39

Respiratory diaphragm External intercostal muscles Sternomasatoids Serratus anterior muscles Scalene muscles

Question 40

What muscles are inspiratory muscles?

Answer 40

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

Question 41

The combination of lung volumes form what?

Answer 41

> they form lung capacities

Question 42

What is the formula for alveolar ventilation?

Answer 42

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