"Medical Physiology Pulmonary Mechanics I Amit S. Dhamoon" SANA

Question 1

What is the difference between oxygenation and ventilation?

Answer 1

Oxygenation is getting oxygen to the blood vessels and tissues. Ventilation is the amount of air inspired and expired.

Question 2

What gas is used as a surrogate to measure ventilation?

Answer 2

CO2

Question 3

You are watching your favorite TV show when something exciting happens and you begin hyperventilating. What will happen to your blood CO2 level?

Answer 3

Blood C02 level would decrease as you would ventilate your lungs more than needed. This is respiratory alkalosis.

Question 4

Which of the following leads to respiratory acidemia?

a. hypoventilation
b. hyperventilation

Answer 4

a. hypoventilation

Question 5

Oxygen saturation is a good measure of oxygenation. What are two ways to measure it?

Answer 5

Pulse oximeter and radial artery lab analysis.

Question 6

A capnography is a device used to measure your _____

Answer 6

CO2 levels

Question 7

Your patient has asthma. What does this mean for her lung tidal volume?

Answer 7

Her tidal volume will be lower

Question 8

In your asthmatic patient, the lung tidal volume is very low. How will this effect her respiratory rate? (hint: use MV = RR x TV)

Answer 8

Because the minute ventilation needs to be maintained, the respiratory rate will increase to compensate for the lower tidal volume.

Question 9

In respiratory muscle paralysis, which of the following results and why?

a. hyperventilation and increased CO2 levels
b. hypoventilation and decreased CO2 levels
c. hyperventilation and decreased CO2 levels
d. hypoventilation and increased CO2 levels

Answer 9

d. hypoventilation results and increased CO2 levels

Question 10

Explain the reasoning behind the brown-bag breathing done to fight off hyperventilation.

Answer 10

Breathing into and out of the brown bag allows us increased the CO2 level in the bag and breath in a higher reservoir of CO2, thus raising our CO2 levels (which have lowered as a result of hyperventilation).

Question 11

At rest, our lungs are performing what kind of ventilation?

Answer 11

negative-pressure ventilation

Question 12

A sleep apnea machine is an example of what kind of ventilation?

Answer 12

positive-pressure ventilation

Question 13

In patients with severe COPD, heart failure and asthma, what kind of ventilation should be used?

Answer 13

postivie-pressure ventilation

Question 14

If there is a reduction in pressure in the intrapleural cavity outside the lung but inside the chest wall, will the lung inflate or deflate? Why?

Answer 14

Inflate, this is negative-pressure.

Question 15

Upon chest x-ray, you find that your patient’s right lung is extremely radiolucent and black, indicating that there is air in the pleural space. What pathology is this?

Answer 15

Pneumothorax

Question 16

In a pneumothorax, why does the lung separate from the chest wall?

Answer 16

As air gets in the middle of the pleural cavity, the chest wall will want to expand while the lung will want to recoil, now that it isn’t held close to the chest wall through the surfactant.

Question 17

How does an esophageal balloon help measure intrapleural pressures?

Answer 17

The esophagus is so compliant that it can pick up changes in the pressure once the balloon is swallowed.

Question 18

At what two stages of breathing is the flow 0?

Answer 18

At the end of inspiration and at the end of expiration

Question 19

During end expiration, what is the alveolar pressure?

Answer 19

its the same as the atmospheric pressure (0).

Question 20

As the chest wall expands during inspiration, the intrapleural pressure _______

Answer 20

becomes more negative

Question 21

The alveolar pressure during inspiration is ______ (lower/higher) than during end expiration.

Answer 21

lower (it becomes negative)

Question 22

During a deep breath in, the diaphragm will____

Answer 22

expand and stretch lower down

Question 23

During normal inspiration, what the muscles helping expand the chest wall outwards?

Answer 23

External intercostal and scalene

Question 24

A surgeon accidentally injures a patient’s phrenic nerve. What will happen to the patient’s diaphragm and chest wall during inspiration?

Answer 24

The chest wall will expand but the diaphragm will be pulled upwards by the external intercostals and scalene muscles.

Question 25

Expiration is a _________ (active/passive) process, while inspiration is ________ (active/passive) process.

Answer 25

expiration = passive, inspiration = active

Question 26

What muscles are recruited during expiration at rest? What muscles are recruited during forced expiration?

Answer 26

rest expiration = passive

forced expiration = abdominal muscles and internal intercostals

Question 27

In patients with emphysema, expiration is always _____ (active/passive)? Why?

Answer 27

Active, because their lungs have lost their elasticity and do not recoil and expel air easily, making it necessary for them to use their abdominal and intercostal muscles.

Question 28

Which of the following sets the degree of inflation of the chest wall?

a. transmural lung pressure
b. transmural chest wall pressure
c. transmural total pressure

Answer 28

b

Question 29

Which of the following sets the degree of inflation of the lung?

a. transmural lung pressure
b. transmural chest wall pressure
c. transmural total pressure

Answer 29

a

Question 30

Which of the following sets the degree of inflation of the entire system of bag within a bag?

a. transmural lung pressure
b. transmural chest wall pressure
c. transmural total pressure

Answer 30

c

Question 31

Alveolar interdependence indicates that if you expand alveoli in the periphery or the center, the surrounding alveoli will _____

Answer 31

also expand.

Question 32

In a static compliance curve, why does the slope taper off as the transpulmonary pressure increased?

Answer 32

Because at high volumes, the lung becomes less complaint and less and less stretchy.

Question 33

What is the static compliance curve?

Answer 33

It is the volume/pressure relationship during inspiration

Question 34

during initial inspiration, compliance is ______ (high/low)

Answer 34

high

Question 35

In emphysema, there is an accumulation of :

a. alpha antitrypsin
b. neutrophils and proteases
c. macrophages
d. elastin

Answer 35

b: neutrophils accumulate in an attempt to remove smoke particles and release proteases. alpha-antitrypsin usually inhibit proteases. Lung connective tissue is degraded by proteases.

Question 36

In emphysema, lung connective tissue is degraded by ______

Answer 36

proteases

Question 37

In emphysema, a small change is transmural pressure will yield a ________ change in volume.

Answer 37

large

Question 38

Lung compliance is _______ (increased/decreased) during emphysema but is ______ (increased/decreased) during fibrosis of the lungs.

Answer 38

increased; decreased

Question 39

What are two things you might notice on a chest x-ray of a emphysema patient?

Answer 39

1. radiolucent/black space due to too much air in lungs

2. flatter diaphragm due to increased compliance

Question 40

What might you notice on a chest x-ray of a lung fibrosis patient?

Answer 40

more collagen and elastin deposition (more white stuff on x-ray)