"Medical Physiology Pulmonary Mechanics I Amit S. Dhamoon" SANA Flashcards
What is the difference between oxygenation and ventilation?
Oxygenation is getting oxygen to the blood vessels and tissues. Ventilation is the amount of air inspired and expired.
What gas is used as a surrogate to measure ventilation?
CO2
You are watching your favorite TV show when something exciting happens and you begin hyperventilating. What will happen to your blood CO2 level?
Blood C02 level would decrease as you would ventilate your lungs more than needed. This is respiratory alkalosis.
Which of the following leads to respiratory acidemia?
a. hypoventilation
b. hyperventilation
a. hypoventilation
Oxygen saturation is a good measure of oxygenation. What are two ways to measure it?
Pulse oximeter and radial artery lab analysis.
A capnography is a device used to measure your _____
CO2 levels
Your patient has asthma. What does this mean for her lung tidal volume?
Her tidal volume will be lower
In your asthmatic patient, the lung tidal volume is very low. How will this effect her respiratory rate? (hint: use MV = RR x TV)
Because the minute ventilation needs to be maintained, the respiratory rate will increase to compensate for the lower tidal volume.
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
d. hypoventilation results and increased CO2 levels
Explain the reasoning behind the brown-bag breathing done to fight off hyperventilation.
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).
At rest, our lungs are performing what kind of ventilation?
negative-pressure ventilation
A sleep apnea machine is an example of what kind of ventilation?
positive-pressure ventilation
In patients with severe COPD, heart failure and asthma, what kind of ventilation should be used?
postivie-pressure ventilation
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?
Inflate, this is negative-pressure.
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?
Pneumothorax
In a pneumothorax, why does the lung separate from the chest wall?
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.
How does an esophageal balloon help measure intrapleural pressures?
The esophagus is so compliant that it can pick up changes in the pressure once the balloon is swallowed.
At what two stages of breathing is the flow 0?
At the end of inspiration and at the end of expiration
During end expiration, what is the alveolar pressure?
its the same as the atmospheric pressure (0).
As the chest wall expands during inspiration, the intrapleural pressure _______
becomes more negative
The alveolar pressure during inspiration is ______ (lower/higher) than during end expiration.
lower (it becomes negative)
During a deep breath in, the diaphragm will____
expand and stretch lower down
During normal inspiration, what the muscles helping expand the chest wall outwards?
External intercostal and scalene
A surgeon accidentally injures a patient’s phrenic nerve. What will happen to the patient’s diaphragm and chest wall during inspiration?
The chest wall will expand but the diaphragm will be pulled upwards by the external intercostals and scalene muscles.
Expiration is a _________ (active/passive) process, while inspiration is ________ (active/passive) process.
expiration = passive, inspiration = active
What muscles are recruited during expiration at rest? What muscles are recruited during forced expiration?
rest expiration = passive
forced expiration = abdominal muscles and internal intercostals
In patients with emphysema, expiration is always _____ (active/passive)? Why?
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.
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
b
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
a
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
c
Alveolar interdependence indicates that if you expand alveoli in the periphery or the center, the surrounding alveoli will _____
also expand.
In a static compliance curve, why does the slope taper off as the transpulmonary pressure increased?
Because at high volumes, the lung becomes less complaint and less and less stretchy.
What is the static compliance curve?
It is the volume/pressure relationship during inspiration
during initial inspiration, compliance is ______ (high/low)
high
In emphysema, there is an accumulation of :
a. alpha antitrypsin
b. neutrophils and proteases
c. macrophages
d. elastin
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.
In emphysema, lung connective tissue is degraded by ______
proteases
In emphysema, a small change is transmural pressure will yield a ________ change in volume.
large
Lung compliance is _______ (increased/decreased) during emphysema but is ______ (increased/decreased) during fibrosis of the lungs.
increased; decreased
What are two things you might notice on a chest x-ray of a emphysema patient?
- radiolucent/black space due to too much air in lungs
2. flatter diaphragm due to increased compliance
What might you notice on a chest x-ray of a lung fibrosis patient?
more collagen and elastin deposition (more white stuff on x-ray)
