During Heavy Exercise, the PO₂ in Muscle May Drop to 20

question 88

Multiple Choice

During heavy exercise, the pO₂ in muscle may drop to 20 mm Hg. Considering the oxygen-hemoglobin dissociation curve below, what is the approximate percent O₂ saturation of hemoglobin in venous blood returning from skeletal muscles during heavy exercise?

• A)approximately 100%
• B)approximately 75%
• C)approximately 50%
• D)approximately 20%
• E)nearly 0%

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Definitions:

Endocardium

The innermost layer of tissue that lines the chambers of the heart, providing a smooth surface for blood flow.

Epicardium

The outermost layer of the wall of the heart. Also known as the visceral pericardium.

Pericardium

A membrane that covers the heart and large blood vessels attached to it.

Cardiac Conduction

The process by which the heart's electrical impulses are generated and transmitted, facilitating heartbeats.