Sign up ×
Biology Stack Exchange is a question and answer site for biology researchers, academics, and students. It's 100% free, no registration required.

For further investigation into the progress of the blood pressure, we will measure a patient's blood pressure in the superior vena cava measured during inhalation and during an exhalation. His heart function remains the same during the measurements

Why is this subject's blood pressure in the superior vena cava during inhalation less than during the exhalation?

share|improve this question

closed as off-topic by Majid, Raoul, Bez, anongoodnurse, Luke Jan 26 at 17:02

This question appears to be off-topic. The users who voted to close gave this specific reason:

  • "Homework questions are off-topic on Biology unless you have shown your attempt at an answer. For more information see our homework policy." – Community, Raoul, Bez, anongoodnurse, Luke
If this question can be reworded to fit the rules in the help center, please edit the question.

1 Answer 1

The diaphragm moves down during inspiration. This leads to air being sucked in, due to the pressure difference created. The converse is true during expiration. As the thoracic space is where the SVC sits, it's pressure decreases during inspiration as it is subjected to the surrounding decrease in pressure.

share|improve this answer

Not the answer you're looking for? Browse other questions tagged or ask your own question.