Preload, Afterload and the Frank-Starling Relationship · seed 1 · A4, ink-friendly. The answer key prints on its own page for grown-ups.

More in, more out

Science · The Human Body · ages 19-21
Name ______________________   Date ____________

  1. What is the filling load of the chamber?

    • Stretch of the wall before the squeeze
    • Pressure fought during ejection
    • Speed of the pacemaker

  2. How is output per minute calculated from beat volume and rate?

    • Beat volume plus rate
    • Beat volume minus rate
    • Beat volume times rate

  3. The pressure fought during ejection climbs. What happens to each beat?

    • It raises each beat
    • It trims each beat
    • It changes nothing

  4. Only filling rises while strength stays put. What happens on the graph?

    • Slide on the same curve
    • Jump to a higher curve
    • Leave the graph entirely

  5. Each beat ejects 70 units and the rate is 70 per minute. What is the output?

    Answer: ______________

  6. The right side briefly ships more than the left. What follows?

    • Left side pumps less forever
    • Blood piles up on one side
    • Pressures shift until both ship the same

  7. Same filling, bigger beat than before. A friend calls it a filling change. Right?

    • No, same filling with more output means strength itself rose
    • Yes, that is always a filling change
    • Yes, strength never matters

  8. Blood returning to the pump rises and strength stays flat. Predict each beat.

    • Each beat shrinks
    • Each beat grows
    • Rate must fall
LightMySky · lightmysky.comW1-mt_WK8o6OPZ-O-s1

Answer key

For grown-ups. Fold this page away before handing over the rest.

More in, more out W1-mt_WK8o6OPZ-O-s1

  1. Stretch of the wall before the squeeze · Filling stretches the wall and that stretch fixes the next squeeze.
  2. Beat volume times rate · Each minute ships what one beat ejects multiplied by the beat count.
  3. It trims each beat · Fighting higher pressure makes ejection harder, so less leaves per beat.
  4. Slide on the same curve · Same pump, more stretch: you move along the curve you already sit on.
  5. 4900 · 70 units per beat times 70 beats gives 4900 units per minute.
  6. Pressures shift until both ship the same · The sides sit in series, so each side feeds the other and they rebalance alone.
  7. No, same filling with more output means strength itself rose · Equal stretch with a bigger beat can only come from a shifted curve.
  8. Each beat grows · More return means more stretch, and stretch raises the next ejection.
Worksheet · LightMySky