Question

multiple choice question
when sitting or standing, what is the major force pushing blood from the head towards the heart?

gravity

the skeletal pump

cardiac suction

pressure generated by the heart

the thoracic (respiratory) pump

Explanation:

To determine the major force pushing blood from the head to the heart when sitting/standing:

• Gravity: When upright, gravity helps pull blood down (toward the heart from the head) as the head is above the heart.
• Skeletal pump: Aids blood flow from limbs (not head) via muscle contractions.
• Cardiac suction: Not a major force for head - to - heart blood flow.
• Pressure from heart: Primarily pushes blood away from the heart (e.g., to the body, lungs), not toward it from the head.
• Thoracic pump: Aids venous return from the abdomen/thorax, not the head.

So gravity is the major force here.

Answer:

A. Gravity