Ms. Y has suddenly experienced a substantial loss of endurancecapacity. Six months ago, she was a good runner and swimmer,capable of exercising for hours, yet now she can only exercise fora few minutes before tiring.

As the local physiology expert, you are called in to help theM.D. diagnose the problem.

Her red blood cell count and hemoglobin levels are normal. Whatproblems do these results eliminate? 1 pt

Heart rate is normal at rest, but goes to a very high level(near 200 beats per min) even with mild exercise.

First, you must determine whether the primary problem is withthe respiratory system or the cardiovascular system.

You measure arterial P_O2, arterial hemoglobin percent saturation, and arterial P_CO2.

If the problem is with the respiratory system, what should thenumbers be for these parameters? (2 pts)

Arterial P_O2

Hemoglobin percent saturation:

arterial P_CO2:

Explain why. 1 pt.

If the problem is with the cardiovascular system (such as anemiaor a weak left ventricle), what should the numbers be for theseparameters? Explain why (2 pts)

Arterial P_O2:

arterial hemoglobin percent saturation:

arterial P_CO2:

Explain why.

Suppose you determine that the problem is with the respiratorysystem.

Your next goal is to determine whether the problem is withalveolar ventilation (getting fresh air to the alveoli, as canoccur with asthma) or diffusion (getting oxygen from alveoli toblood, as can occur with pulmonary edema). Assume you can measureoxygen (P_O2) in the exhaled air, the alveoli, and thearterial blood.

How should these P_O2 values compare to normal if theproblem is inadequate alveolar ventilation? (3 pts)

exhaled P_O2?

alveolar P_O2?

arterial P_O2?

Explain why .

How should these P_O2 values compare to normal if theproblem is a poor alveolar diffusing capacity? (2 pts)

exhaled P_O2?

alveolar P_O2?

arterial P_O2?

Explain why.