Exam 3: 13 Mar

Question 1

What is the significance of flow volume loops in pulmonary function tests?

Answer 1

They help assess maximal peak expiratory force and airway collapse.

Question 2

What is forced vital capacity?

Answer 2

The maximum amount of air that can be forcibly exhaled after taking the deepest breath possible.

Question 3

How does airway collapse affect expiratory flow rate?

Answer 3

It reduces the expiratory flow rate due to obstruction.

Question 4

What is the relationship between lung volume and airway resistance?

Answer 4

Lower lung volume increases airway resistance.

Question 5

True or False: In restrictive lung diseases, peak expiratory flow rate is typically higher.

Answer 5

False

Question 6

What pressures are involved in normal expiration?

Answer 6

Pleural pressure and elastic recoil pressure.

Question 7

What happens to airway pressure during forced expiration?

Answer 7

It increases significantly due to applied force.

Question 8

What is the role of pleural pressure in preventing airway collapse?

Answer 8

Negative pleural pressure helps keep the airways open.

Question 9

Fill in the blank: The _______ is essential for maintaining airflow through the lungs.

Answer 9

pressure gradient

Question 10

What can cause small airway collapse?

Answer 10

High surrounding pressure compared to small airway pressure.

Question 11

What is meant by ‘airway traction’?

Answer 11

The support provided by elastic tissue to keep small airways open.

Question 12

How does emphysema affect elastic recoil in the lungs?

Answer 12

It reduces elastic recoil due to loss of elastic tissue.

Question 13

What is a common example of fixed intra or extra thoracic obstruction?

Answer 13

An endotracheal tube.

Question 14

True or False: A smaller diameter endotracheal tube increases airflow resistance.

Answer 14

True

Question 15

What is the relationship between elastic recoil and lung compliance?

Answer 15

Less elastic recoil leads to increased lung compliance.

Question 16

What is the effect of low lung volume on small airways?

Answer 16

It narrows small airways, increasing the risk of collapse.

Question 17

How does the structure of upper respiratory tract airways differ from small airways?

Answer 17

Upper airways are supported by cartilage, while small airways are not.

Question 18

What happens to the pressure gradient as you move away from the alveoli during expiration?

Answer 18

The pressure gradient decreases.

Question 19

What happens during passive expiration?

Answer 19

Air is pushed out of the lungs by elastic recoil.

Question 20

Fill in the blank: The pressure inside the small airways must be _______ than the surrounding pressure to prevent collapse.

Answer 20

greater

Question 21

What is the impact of airway obstruction on flow volume loops?

Answer 21

It alters the shape of the loops, indicating resistance.

Question 22

What condition often leads to the loss of elastic tissue in the lungs?

Answer 22

Emphysema.

Question 23

What is the primary factor that influences airway collapse in small airways?

Answer 23

The balance between internal airway pressure and external environmental pressure.

Question 24

How does a healthy lung maintain airway patency?

Answer 24

Through sufficient elastic tissue and pressure gradients.

Question 25

What happens when a smaller diameter tube is placed in the trachea?

Answer 25

Higher resistance to air flow ## Footnote Causes difficulty in both inspiration and expiration.

Question 26

What does obstruction in the flow volume loop typically affect?

Answer 26

Limits both inspiration and expiration ## Footnote It cuts off the expired portion of the flow volume loops.

Question 27

What is an example of a fixed obstruction in the respiratory system?

Answer 27

Endotracheal tube ## Footnote It obstructs airflow throughout the respiratory cycle.

Question 28

What characterizes a variable intrathoracic obstruction?

Answer 28

Affects only expiration ## Footnote It is not present throughout the entire respiratory cycle.

Question 29

In the context of variable intrathoracic obstruction, what happens during forced expiration?

Answer 29

Airway collapse can occur due to positive pressure ## Footnote This can happen if elastic recoil is not normal.

Question 30

What condition can cause variable intrathoracic obstruction?

Answer 30

Emphysema or asthma ## Footnote These conditions typically involve small airway collapse.

Question 31

What is a variable extra thoracic obstruction?

Answer 31

Obstruction outside the chest that affects inspiration ## Footnote It can cause airway collapse due to negative pressure.

Question 32

What can lead to variable extra thoracic obstruction?

Answer 32

Paralyzed vocal cords or missing cartilage ## Footnote These conditions may prevent normal airway support.

Question 33

What is the normal FEV1/FVC ratio in healthy individuals?

Answer 33

Approximately 80% ## Footnote This ratio indicates normal lung function.

Question 34

What does FEV1 stand for?

Answer 34

Forced expiratory volume in one second ## Footnote It measures the amount of air expelled in the first second of a forced exhalation.

Question 35

What does FVC stand for?

Answer 35

Forced vital capacity ## Footnote It represents the total amount of air that can be forcibly exhaled.

Question 36

What occurs if the FEV1/FVC ratio is lower than 80%?

Answer 36

Indicates a potential respiratory problem ## Footnote It suggests possible obstruction or restriction in lung function.

Question 37

What is the significance of measuring lung volumes over time during a forced expiratory maneuver?

Answer 37

It helps assess how quickly air can be expelled from the lungs ## Footnote Typically shows how lung volume decreases during expiration.

Question 38

What is a characteristic finding in restrictive lung disease?

Answer 38

Low vital capacity ## Footnote The FEV1 may also be low, but the ratio can be normal.

Question 39

What does a low FEV1 in conjunction with a low FVC suggest?

Answer 39

Restrictive lung disease ## Footnote It indicates a proportionate decrease in both volumes.

Question 40

What might a significantly low FEV1/FVC ratio indicate?

Answer 40

Obstructive lung disease ## Footnote This suggests a problem with airflow, often seen in conditions like COPD.

Question 41

What happens to airway pressure during inspiration with variable extra thoracic obstruction?

Answer 41

Internal airway pressure becomes negative ## Footnote This can cause collapse of the airway if not supported.

Question 42

What does a low force vital capacity indicate?

Answer 42

Restrictive lung disease ## Footnote A low force vital capacity suggests that the lungs cannot expand fully, often seen in conditions like restrictive lung disease.

Question 43

What is the significance of the FEV1 to FVC ratio?

Answer 43

Indicates obstructive or restrictive lung disease ## Footnote A ratio less than 70% usually indicates an obstructive problem, while a higher ratio may suggest restrictive lung disease.

Question 44

What does a flattened expiratory curve suggest?

Answer 44

Obstructive lung disease ## Footnote A hallmark shape change in the flow-volume loop indicates issues with airflow, typical of obstructive lung diseases.

Question 45

How can bronchodilator response help in diagnosing lung conditions?

Answer 45

Indicates airway reactivity ## Footnote If a bronchodilator improves FEV1, it suggests asthma; if not, it may indicate emphysema or another irreversible obstructive condition.

Question 46

What does an increased residual volume indicate?

Answer 46

Obstructive lung disease ## Footnote An increase in residual volume relative to total lung capacity can help differentiate between types of obstructive lung diseases.

Question 47

What is the purpose of the carbon monoxide diffusion test?

Answer 47

Measures surface area available for gas exchange ## Footnote This test assesses how well oxygen and carbon dioxide can transfer between the alveoli and blood.

Question 48

What is the procedure for measuring closing capacity?

Answer 48

Monitor nitrogen concentration during expiration ## Footnote The patient exhales to residual volume, then inhales 100% oxygen and exhales again to measure nitrogen levels.

Question 49

What happens to nitrogen concentration during a vital capacity maneuver with 100% oxygen?

Answer 49

Dilution of nitrogen occurs ## Footnote The nitrogen previously in the lungs gets diluted as oxygen is inhaled, affecting nitrogen concentration in expired air.

Question 50

How does lung volume affect nitrogen dilution?

Answer 50

Base of the lung dilutes nitrogen more than the apex ## Footnote The base of the lung, being less full, allows for more dilution of nitrogen when inhaling oxygen.

Question 51

What is indicated by the first phase of the nitrogen expiration maneuver?

Answer 51

Expiring dead space air ## Footnote This phase includes air that was not involved in gas exchange, primarily from the trachea and bronchi.

Question 52

Fill in the blank: A FEV1/FVC ratio of less than ___ is typically considered a problem in pulmonary function testing.

Answer 52

70 ## Footnote This threshold is used to distinguish between normal and obstructive lung function.

Question 53

What is the expected outcome in a patient with advanced emphysema during a forced expiration test?

Answer 53

Prolonged expiration time with low FEV1 ## Footnote Patients may struggle to empty their lungs due to loss of elastic recoil, leading to a characteristic prolonged expiration.

Question 54

True or False: A normal FEV1 suggests healthy lung function.

Answer 54

True ## Footnote A normal FEV1 indicates that the patient can exhale a sufficient volume of air in one second, suggesting no significant obstructive disease.

Question 55

What are the three main types of lung diseases indicated by pulmonary function tests?

Answer 55

* Obstructive lung disease * Restrictive lung disease * Mixed lung disease ## Footnote These classifications help in diagnosing specific pulmonary conditions based on test results.

Question 56

What is the first phase of the nitrogen expiration maneuver?

Answer 56

The first phase involves expiring dead space air with no nitrogen content ## Footnote This phase represents the anatomical dead space air, approximately 100 cc.

Question 57

What occurs during phase two of the nitrogen expiration maneuver?

Answer 57

Phase two is a transitional period with mixed anatomical dead space air and alveolar air ## Footnote This phase correlates with the Fowler test.

Question 58

What is the primary source of expired air during phase three?

Answer 58

Most expired air during phase three comes from the base of the lung ## Footnote Initially, the base has a lot of nitrogen dilution due to previous emptying.

Question 59

What characterizes phase four of the nitrogen expiration maneuver?

Answer 59

Phase four is marked by an abrupt change in expired nitrogen concentration due to small airway collapse ## Footnote This indicates a shift from air coming from the base to the apex of the lung.

Question 60

What are the terms used to describe the inflection point between phases three and four?

Answer 60

The terms are closing capacity and closing volume ## Footnote Closing capacity includes closing volume plus residual volume.

Question 61

How does aging affect the closing capacity and closing volume?

Answer 61

Closing capacity and closing volume increase with age ## Footnote This is due to loss of elastic tissue, resulting in earlier small airway collapse.

Question 62

What happens to residual volume (RV) as a person ages?

Answer 62

Residual volume tends to increase as we age ## Footnote This is linked to difficulties in emptying parts of the lung.

Question 63

At what age does small airway collapse begin to occur during normal breathing?

Answer 63

Small airway collapse begins around age 55 ## Footnote This occurs even in individuals who are in perfect health.

Question 64

What is the impact of small airway collapse on the work of breathing in older adults?

Answer 64

Older adults experience increased work of breathing due to frequent small airway collapse ## Footnote They have to exert more effort to breathe compared to younger individuals.

Question 65

True or False: Total lung capacity significantly changes with age.

Answer 65

False ## Footnote Total lung capacity remains relatively constant as we age.

Question 66

What is the significance of the nitrogen meter in lung function testing?

Answer 66

The nitrogen meter is used to detect small changes in lung function related to airway behavior ## Footnote It can help identify respiratory issues before they become serious.

Question 67

Fill in the blank: The transitional phase in the nitrogen expiration maneuver is similar to the _______.

Answer 67

[Fowler test]

Question 68

What happens to the proportion of expired air from different lung regions during phase three?

Answer 68

As expiration progresses, the proportion shifts from the base to the apex of the lung ## Footnote This reflects the emptying pattern of the lungs.

Question 69

How does the collapse of small airways affect nitrogen concentration in the expired air?

Answer 69

Collapse leads to a decrease in nitrogen concentration in expired air from those alveoli ## Footnote This results in an abrupt change in the nitrogen concentration curve.

Question 70

What is Full Body plethysmography?

Answer 70

A pulmonary function test that measures lung volumes and capacities in a sealed chamber ## Footnote It involves complex equipment and is not commonly visualized.