Exam 3: 6 Mar Basic Pulmonary Function Testing And Gas Exchange

Question 1

What is dead space in the context of pulmonary function?

Answer 1

Dead space refers to the air in the upper airways and conducting zones that does not participate in gas exchange

In healthy individuals, dead space is limited to chemical death rates.

Question 2

How much of a normal tidal breath (500 cc) typically reaches the alveoli?

Answer 2

About 350 cc of the tidal breath reaches the alveoli, while the remaining 150 cc is dead space air.

Question 3

What is the formula for calculating the partial pressure of a gas?

Answer 3

The partial pressure of a gas is equal to the fractional concentration of the gas multiplied by the total pressure

Commonly used total pressures are 760 mmHg or 713 mmHg after accounting for vapor pressure of water.

Question 4

What is the normal alveolar pressure of nitrogen in millimeters of mercury?

Answer 4

569 millimeters of mercury.

Question 5

Fill in the blank: The concentration of nitrogen in lung air is approximately ______.

Answer 5

75%.

Question 6

What happens to the concentration of nitrogen in lung air compared to dry atmospheric air?

Answer 6

It decreases from about 80% in dry atmospheric air to about 75% in lung air due to water vapor.

Question 7

True or False: The total pressure of all gases at sea level is 760 mmHg.

Answer 7

True.

Question 8

What is Fowler’s test used for?

Answer 8

Fowler’s test analyzes the nitrogen content in expired air to assess pulmonary function.

Question 9

What is the expected expired nitrogen concentration when a healthy person breathes room air?

Answer 9

About 75% to 80% nitrogen concentration.

Question 10

What is the significance of using a source of 100% oxygen in pulmonary function tests?

Answer 10

It allows for the measurement of nitrogen coming from the lungs, as the inspired air contains no nitrogen.

Question 11

Fill in the blank: To find the nitrogen concentration in lung air, divide the alveolar pressure of nitrogen by ______.

Answer 11

760.

Question 12

What does a nitrogen meter measure during a pulmonary function test?

Answer 12

The concentration of nitrogen in the expired gas.

Question 13

What is the role of water vapor in gas exchange within the lungs?

Answer 13

Water vapor displaces some of the gas in the lungs, affecting the concentration measurements.

Question 14

What is the formula to find the concentration of a gas in the lungs if the partial pressure and total pressure are known?

Answer 14

Fractional concentration = Partial pressure / Total pressure.

Question 15

What does the term ‘anatomical dead space’ refer to?

Answer 15

The volume of air in the conducting zones where no gas exchange occurs.

Question 16

What is the significance of the transitional zone between dead space air and alveolar air?

Answer 16

It allows for some mixing and minor gas exchange between dead space air and alveolar air.

Question 17

In pulmonary function tests, why is it important to account for water vapor?

Answer 17

To accurately determine the concentration of gases in the lungs, as water vapor displaces some of the gas volume.

Question 18

What is the expected partial pressure of nitrogen when inspiring 100% oxygen?

Answer 18

569 millimeters of mercury

Question 19

What is the composition of the first part of the inspired breath when breathing 100% oxygen?

Answer 19

Contains no nitrogen

Question 20

What is anatomical dead space?

Answer 20

The portion of the respiratory system where no gas exchange occurs

Question 21

What should be expected in the first portion of expired breath after inhaling 100% oxygen?

Answer 21

0% nitrogen

Question 22

What is the alveolar plateau in expired breath?

Answer 22

A phase where the expired nitrogen concentration stabilizes

Question 23

How much anatomical dead space is expected in a healthy 20-year-old?

Answer 23

About 150 CC’s

Question 24

What is the nitrogen washout test used for?

Answer 24

To analyze ventilation distribution in the lungs

Question 25

What is the expected nitrogen concentration in expired air from a healthy individual after breathing normally?

Answer 25

Dilution of nitrogen concentration occurs with each breath

Question 26

What is the normal endpoint for the nitrogen washout test in a healthy individual?

Answer 26

2.5% nitrogen concentration

Question 27

What is an abnormal result in the nitrogen washout test?

Answer 27

Taking greater than seven minutes to reach 2.5% nitrogen concentration

Question 28

What indicates uneven ventilation in the nitrogen washout test?

Answer 28

Scattered data points and irregular nitrogen dilution

Question 29

What can cause a delay in nitrogen washout besides uneven ventilation?

Answer 29

Large lung capacity in individuals with COPD

Question 30

What does the flow-volume graph represent?

Answer 30

Air flow rates during maximal inspiration and expiration

Question 31

What happens to air flow rate during expiration as lung volume decreases?

Answer 31

The air flow rate slows down

Question 32

What is the maximum expected peak air flow rate during expiration?

Answer 32

About 10 liters per second

Question 33

What is the significance of the vital capacity in respiratory function?

Answer 33

It represents the maximum amount of air that can be expelled from the lungs

Question 34

Fill in the blank: The anatomical dead space should have ______% nitrogen in it after inhaling 100% oxygen.

Answer 34

0

Question 35

True or False: The first breath after inhaling 100% oxygen should have a higher nitrogen concentration than subsequent breaths.

Answer 35

False

Question 36

What happens to the nitrogen concentration in the lungs after multiple breaths of 100% oxygen?

Answer 36

It continues to dilute with each breath

Question 37

What does a normal nitrogen washout test result look like on a graph?

Answer 37

A smooth, orderly reduction in nitrogen concentration

Question 38

In a nitrogen washout test, what is indicated by a longer time to reach the endpoint?

Answer 38

Potentially unhealthy lung function

Question 39

What is the relationship between lung size and nitrogen washout test results?

Answer 39

Larger lungs may require longer to wash out nitrogen due to increased volume

Question 40

What should be monitored during the nitrogen washout test?

Answer 40

Expired gas nitrogen content over time

Question 41

What happens to the air flow rate as lung volumes decrease?

Answer 41

The air flow rate slows down as we get towards lower lung volumes.

Question 42

What is the total lung capacity?

Answer 42

The total lung capacity is the maximum amount of air that the lungs can hold.

Question 43

What is vital capacity?

Answer 43

The vital capacity is the difference between total lung capacity and residual volume.

Question 44

Describe the relationship between effort and expired air flow.

Answer 44

At high lung volumes, expired air flow is effort dependent; at low lung volumes, it becomes effort independent.

Question 45

What is effort dependence in the context of lung function?

Answer 45

Effort dependence refers to the degree to which expiratory flow rate is affected by the effort applied.

Question 46

What is effort independence in the context of lung function?

Answer 46

Effort independence occurs when the maximum expired flow rate is capped and does not increase with additional effort.

Question 47

What happens to the expiratory flow rate during maximal effort?

Answer 47

The expired air flow picks up quickly, peaks, and then tapers off throughout expiration.

Question 48

What muscle groups are primarily involved in forced expiration?

Answer 48

* Internal intercostal muscles * Abdominal muscles

Question 49

What is elastic recoil pressure?

Answer 49

Elastic recoil pressure is the pressure generated when the lungs are stretched to total lung capacity.

Question 50

How does a patient's health affect their expiratory flow rate?

Answer 50

The more unhealthy a patient is, the slower they are able to expel air.

Question 51

What is the typical pleural pressure during maximal effort expiration?

Answer 51

Pleural pressure is usually positive during maximal effort expiration.

Question 52

What is the significance of the flow volume loop?

Answer 52

The flow volume loop helps visualize the relationship between lung volume and flow rate during expiration and inspiration.

Question 53

What is FVC?

Answer 53

FVC stands for forced vital capacity, referring to the maximum amount of air that can be forcibly exhaled.

Question 54

What does a lower residual volume indicate in restrictive lung disease?

Answer 54

Lower residual volume indicates less air remaining in the lungs after expiration due to increased elastic tissue.

Question 55

What does a higher residual volume indicate in obstructive lung disease?

Answer 55

Higher residual volume indicates that the lungs are fuller at higher pleural pressures, making it difficult to expel air.

Question 56

How does vital capacity differ between restrictive and obstructive lung diseases?

Answer 56

* Restrictive lung disease: lower vital capacity * Obstructive lung disease: smaller vital capacity due to increased lung fullness

Question 57

What is the typical shape of the expiratory flow rate curve in healthy lungs?

Answer 57

The curve resembles an upside-down ice cream cone.

Question 58

True or False: The inspiratory flow rate is usually prioritized over the expiratory flow rate in pulmonary function tests.

Answer 58

False

Question 59

Fill in the blank: The maximum expiratory flow rate is affected by _______ and _______.

Answer 59

elastic recoil pressure and pleural pressure

Question 60

What happens to the time required for expiration in patients with low elastic recoil?

Answer 60

More time is needed for expiration due to slower passive forces.

Question 61

What is the significance of the peak inspiratory flow rate?

Answer 61

The peak inspiratory flow rate occurs at the halfway point of the inspiration loop.

Question 62

What is vital capacity?

Answer 62

The maximum amount of air a person can exhale after a maximum inhalation.

Question 63

What is the typical vital capacity for a healthy individual?

Answer 63

Approximately four and a half liters.

Question 64

How does vital capacity differ in restrictive lung disease?

Answer 64

It is lower than normal, approximately three liters.

Question 65

In obstructive lung disease, what happens to vital capacity?

Answer 65

It is smaller due to increased residual volume.

Question 66

What is the relationship between airflow rate and disease severity?

Answer 66

Lower airflow rate usually indicates worse disease.

Question 67

What is FBC an abbreviation for?

Answer 67

Forced Vital Capacity maneuver.

Question 68

What does a flow volume loop typically not provide?

Answer 68

Specific values for residual volume.

Question 69

What is the significance of residual volume in lung disease?

Answer 69

A large residual volume may indicate severe disease.

Question 70

What is the role of positive pleural pressure during forced expiratory maneuvers?

Answer 70

It affects the ability of airways to stay open.

Question 71

What happens to airway pressure as air moves up the respiratory tree?

Answer 71

Airway pressure decreases.

Question 72

What supports the structure of the conducting zones in the respiratory system?

Answer 72

Cartilage.

Question 73

What is a vulnerable point in the small airways?

Answer 73

The area just before cartilage support begins.

Question 74

What occurs if alveolar pressure is low but pleural pressure is high?

Answer 74

Small airway collapse may happen.

Question 75

True or False: The shape of the flow volume loop can provide information about lung disease.

Answer 75

True.

Question 76

Fill in the blank: The lower the vital capacity, the ______ the disease.

Answer 76

worse.

Question 77

What is the significance of expiratory flow rate in lung function tests?

Answer 77

It indicates how well air can be expelled from the lungs.

Question 78

What can be inferred from a maximal forced expiratory flow rate?

Answer 78

It provides insight into airway obstruction.

Question 79

What is typically not plotted in flow volume loops from pulmonary function labs?

Answer 79

Specific residual volume values.

Question 80

What is the relationship between vital capacity and disease severity?

Answer 80

Typically, the sicker you are, the smaller your vital capacity.