Hypothalamic and Pituitary Axes and Layered Feedback · seed 1 · A4, ink-friendly. The answer key prints on its own page for grown-ups.

Three levels, one loop

Science · The Human Body · ages 20-22
Name ______________________   Date ____________

  1. Why does each step amplify the signal?

    • Hormones shrink as they travel
    • Feedback adds new hormone
    • One cell above drives many cells below

  2. Which order runs a three level hormone axis?

    • Hypothalamus, pituitary, target gland
    • Gland, pituitary, hypothalamus
    • Pituitary, gland, hypothalamus

  3. The final hormone suppresses release at both upper levels.

    Circle one:   True   False

  4. The target gland fails outright. What do labs show?

    • All three levels fall together
    • Final low while both upper levels climb
    • All three levels climb together

  5. In the adrenal axis, what drives cortisol release?

    • Cortisol driving itself
    • ACTH from the pituitary
    • Insulin from the pancreas

  6. A patient takes the final hormone daily for months. What happens to the axis?

    • Upper levels surge higher
    • The gland grows larger
    • Upper levels and the native gland go quiet

  7. Feedback in an axis amplifies the downward signal to make it louder.

    Circle one:   True   False

  8. Upper hormones are high but the final product is low. Where is the fault?

    • The target gland itself has failed
    • The hypothalamus is lazy
    • Feedback is too strong
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Answer key

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

Three levels, one loop W1-mt_tgRAAq3Poe-s1

  1. One cell above drives many cells below · Each level commands a crowd at the next one down.
  2. Hypothalamus, pituitary, target gland · Command flows from brain to pituitary to distant gland.
  3. True · That double feedback holds levels near their set point.
  4. Final low while both upper levels climb · Lost product lifts feedback, so the upper drive rises vainly.
  5. ACTH from the pituitary · The middle level commands the target gland.
  6. Upper levels and the native gland go quiet · The brain reads plenty and cuts its own drive.
  7. False · Amplification runs downward, while feedback steadies from above.
  8. The target gland itself has failed · High drive with low product means the bottom cannot answer.
Worksheet · LightMySky