The Autonomic Nervous System and Its Two Outflows · seed 1 · A4, ink-friendly. The answer key prints on its own page for grown-ups.

Your two autopilots for the organs

Science · The Human Body · ages 20-21
Name ______________________   Date ____________

  1. How do the two sides place their ganglia?

    • Both share one ganglion chain
    • Both hide ganglia inside the brain
    • Sympathetic chains near the cord, parasympathetic terminals near organs

  2. Where do the sympathetic and parasympathetic outflows leave?

    • Sympathetic middle cord, parasympathetic cranial plus sacral
    • Sympathetic cranial plus sacral, parasympathetic middle cord
    • Both leave only from the neck cord

  3. The heart hears from both outflows, pulling opposite ways.

    Circle one:   True   False

  4. Phenylephrine drops go into the eye. What happens to the pupil?

    • It widens the pupil
    • It shrinks the pupil
    • It freezes all eye motion

  5. A patient takes a beta blocker. What happens to heart rate and pressure?

    • Both spike sharply
    • Heart rate and pressure fall
    • Nothing changes at all

  6. An autonomic efferent path runs in how many steps? Type the count.

    Answer: ______________

  7. Blood pressure rises. Which sensor starts the correcting loop?

    • Light sensors in the retina
    • Stretch sensors in the aorta wall
    • Taste buds on the tongue

  8. A student says sympathetic ganglia use norepinephrine. What is wrong?

    • Ganglia use no transmitters
    • Sympathetic nerves never reach ganglia
    • Ganglia use acetylcholine on nicotinic receptors
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Answer key

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

Your two autopilots for the organs W1-mt_bnVgu4T4E9-s1

  1. Sympathetic chains near the cord, parasympathetic terminals near organs · Sympathetic relays hug the spine; parasympathetic relays sit by the targets.
  2. Sympathetic middle cord, parasympathetic cranial plus sacral · Sympathetic is thoracolumbar while parasympathetic is craniosacral.
  3. True · One input speeds the heart while the other slows it.
  4. It widens the pupil · Phenylephrine mimics norepinephrine at alpha-1 receptors, dilating the pupil.
  5. Heart rate and pressure fall · Blocking beta receptors mutes adrenergic drive to the heart.
  6. 2 · Preganglionic fiber to ganglion, then postganglionic fiber to organ: two steps.
  7. Stretch sensors in the aorta wall · Aortic baroreceptors report stretch, opening the reflex loop.
  8. Ganglia use acetylcholine on nicotinic receptors · Norepinephrine acts past the ganglia; inside them both systems use acetylcholine.
Worksheet · LightMySky