Question

multiple choice question
during ventricular systole, the av valve cusps move downward, expanding the atrial space. this creates which of the following?

• respiratory pump
• gravity
• cardiac suction
• skeletal muscle pump

Explanation:

To solve this, we analyze each option:

• Respiratory pump: Relates to breathing’s effect on blood flow (e.g., thoracic pressure changes), not AV valve movement. Eliminate.
• Gravity: Influences blood flow direction (e.g., venous return from lower limbs) but is not caused by AV valve movement. Eliminate.
• Cardiac suction: During ventricular systole, AV valve cusps moving downward expand the atrial space, creating a slight negative pressure (suction) that helps draw blood into the atria for the next diastole. This matches the scenario.
• Skeletal muscle pump: Relies on muscle contractions (e.g., walking) to push blood in veins, unrelated to AV valve mechanics. Eliminate.

Answer:

Cardiac suction