The respiratory pump facilitates the return of blood to the heart by
A) raising the pressure gradient between abdominal and thoracic veins during inspiration.
B) decreasing the pressure gradient between abdominal and thoracic veins during inspiration.
C) squeezing blood from the rhythmic contraction of the diaphragm muscle.
D) decreasing the pressure gradient between abdominal and thoracic veins during expiration.
E) raising the pressure gradient between abdominal and thoracic veins during expiration
Answer: A) raising the pressure gradient between abdominal and thoracic veins during inspiration.
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