Oxygen consumption increases with exercise due to the fact that the contracting muscles are doing work and require ATP to produce the contractions.
A) How does the body meet the increased demand for oxygen?
B) Calculate the oxygen consumption of a runner using the following information:
Heart Rate: 130 bpm; Stroke Volume: 270 mL/beat;
Arterial oxygen content: 250 mL O2/L blood,
and Venous oxygen content: 100 O2/L blood.
In order to meet the increased oxygen usage, more blood needs to be delivered to the working muscles. This is accomplished by increasing cardiac output and by vasodilation of blood vessels to the exercising muscles thus increasing flow and delivering more oxygen rich blood. Oxygen consumption can be calculated using the Fick equation.
Qo2 = CO× (arterial oxygen content - venous oxygen content)
However, CO must be calculated first: CO = SV × HR = 130 x 250 = 32.5 L/min
Then Qo2 = 32.5 × (0.250 - 0.100) = 4.875 L O2/min
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