We would like to invite you to join our latest forum at:

address: http://www.farari.org

So hurry up and join us in our

premium site

A Case Study on Human Respiratory Physiology

Go down

A Case Study on Human Respiratory Physiology

Post by MEDI on Wed Jun 02, 2010 11:32 pm

When Charles returned to his apartment at 5 PM in the
evening, he turned on his old kerosene-fueled space heater. It had been
a cold day in late spring and his third floor apartment was chilly.
After spending an hour fixing dinner, he ate while watching the evening
news on TV. He noticed that his vision became progressively blurred.
When he got up to go to the kitchen, he felt lightheaded and unsteady.
Entering the kitchen, he became very disoriented and passed out. The
next thing he remembered was waking up in the intensive care unit of the
hospital. Some friends who had stopped by about 7 PM
had found Charles unconscious on the kitchen floor. They had called an
ambulance, which had rushed Charles, still unconscious, to the hospital.

An arterial blood sample drawn when he first arrived at the hospital
showed the following values:


  1. The blood gas measurements show abnormalities in the partial
    pressure(s) of what gas(es)?

    1. N2, O2 and CO
    2. CO and CO2
    3. CO alone
    4. N2 and CO
    5. O2 and CO

  2. A measurement of Charles’ blood reveals that the O2
    content is low (50% of normal) and hemoglobin is 50% saturated with CO
    (50% HbCO).

    The oxygen-hemoglobin saturation curve in Charles’ blood (50% HbCO)
    and under normal conditions (2% HbCO) is shown below. CO2
    binding to hemoglobin is normal in both instances.

    What is the approximate % saturation of hemoglobin by O2
    in normal arterial blood?

    1. 100%
    2. 97%
    3. 75%
    4. 50%
    5. 35%

  3. What is the maximum amount of O2 (ml/ 100 ml
    blood) that can be carried in Charles’ arterial blood?

    1. 2 ml/100 ml
    2. 5 ml/100 ml
    3. 10 ml/100 ml
    4. 15 ml/100 ml
    5. 20 ml/100 ml

  4. CO enhances the Bohr effect. This means that CO will
    cause a more pronounced shift of the hemoglobin oxygen saturation curve
    to the:

    1. right
    2. left

  5. If the partial pressure of O2 in the body
    tissues is 20 mm Hg, what is the best estimate of the amount of O2
    (ml/100ml) that can be released from Charles’ blood as it circulates in
    his systemic capillaries?

    1. <1 ml /100 ml
    2. 1 ml /100 ml
    3. 2.5 ml /100 ml
    4. 5 ml /100 ml
    5. 10 ml /100 ml

  6. In Charles’ blood, the partial pressure of CO in the
    blood is far lower than the partial pressure of O2, yet the
    percent saturation of hemoglobin by each gas is equal. This result
    indicates that the affinity of hemoglobin for CO is approximately how
    many times greater as compared to O2?

    1. 38
    2. 100
    3. 238
    4. 708
    5. 1783

  7. Would you expect Charles’ disorder to be accompanied by
    chemoreceptor-mediated hyperventilation?

    1. Yes, since the % oxygen saturation of hemoglobin in his
      blood is decreased
    2. Yes, since CO acts as a CNS neurotransmitter and central
      chemoreceptors are located in the brain
    3. Yes, since elevated partial pressure of CO is detected by
      peripheral chemoreceptors in carotid and aortic bodies
    4. No, since the partial pressure of O2 in his
      blood is normal
    5. No, since CO is unable to diffuse across the blood-brain

  8. Fundamentally, Charles’ condition is a problem of:

    1. pulmonary ventilation
    2. diffusion across the respiratory membrane between the
      alveolar air space and the alveolar capillaries
    3. transport of gases between the alveolar capillaries and
      capillary beds in other tissues
    4. exchange of dissolved gases between the blood and the
      interstitial fluid in peripheral tissues
    5. absorption of oxygen and release of carbon dioxide by
      cells in the peripheral tissues

  9. With regard to the physiology of external respiration,
    Charles’ disorder is most analogous to:

    1. barbiturate-induced hypoventilation
    2. altitude sickness
    3. emphysema
    4. acute hemorrhagic anemia

  10. Which of the following is NOT an appropriate component
    of an aggressive treatment plan for Charles’ disorder?

    1. administration of a breathing gas mixture with a high
      percentage of oxygen
    2. alkalization of the blood (increase the pH)
    3. partial blood replacement with normal, compatible whole
    4. administration of a breathing gas mixture with elevated
      levels of carbon dioxide


Posts : 148
Points : 549

Back to top Go down

Re: A Case Study on Human Respiratory Physiology

Post by alanosero on Mon Dec 31, 2012 10:58 pm

thank u ....................................

Posts : 15
Points : 7
Location : Saudi Arabia

Back to top Go down

Back to top

Permissions in this forum:
You cannot reply to topics in this forum