Transmitter Systems and Two Kinds of Receptor · seed 1 · A4, ink-friendly. The answer key prints on its own page for grown-ups.

Two doors for one message

Science · The Human Body · ages 19-20
Name ______________________   Date ____________

  1. What decides whether a signal excites or inhibits its target?

    • The receptor on the receiving cell
    • The shape of the sending cell
    • The length of the axon

  2. What is the time difference between the two receptor kinds?

    • Both act in milliseconds
    • One acts fast and brief, the other slow and lasting
    • Both start cascades inside the cell

  3. Glutamate excites its targets and GABA quiets them.

    Circle one:   True   False

  4. One signal reaches two cells with different receptors. What happens?

    • It excites one and inhibits the other
    • It excites both the same way
    • It has no effect on either

  5. A target cell carries only the slow cascade receptor. What reply do you predict?

    • A brief twitch
    • No reply at all
    • A long lasting shift in activity

  6. What is the correct order of events at the gap?

    • Receptors catch it before release
    • Vesicles spill it, it crosses the gap, then it is cleared
    • It is cleared before it is released

  7. Someone claims one transmitter owns one behaviour. Is that claim right?

    • Yes, each system owns one behaviour
    • No, each behaviour involves many systems
    • Yes, but only for movement

  8. Cleanup crews stop mopping up the gap. What happens to signalling?

    • The reply gets shorter
    • Nothing changes
    • The reply drags on too long
LightMySky · lightmysky.comW1-mt_yXaSbrBxua-s1

Answer key

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

Two doors for one message W1-mt_yXaSbrBxua-s1

  1. The receptor on the receiving cell · The message is the same. The receiver and its receptors give it meaning.
  2. One acts fast and brief, the other slow and lasting · Direct channels answer at once. Cascade receptors take longer and linger.
  3. True · Glutamate is the main exciting signal and GABA is the main quieting one.
  4. It excites one and inhibits the other · One release can do both jobs at once when the two targets carry different receptors.
  5. A long lasting shift in activity · Slow receptors work through inner messengers, so their reply builds slowly and persists.
  6. Vesicles spill it, it crosses the gap, then it is cleared · Release comes first, then crossing and binding, then cleanup for reuse.
  7. No, each behaviour involves many systems · A system touches mood or movement as one player among many, never alone.
  8. The reply drags on too long · Cleanup ends the message on time, so blocking it leaves extra signal behind.
Worksheet · LightMySky