Compare nervous and hormonal control by speed of action
Contrast rapid neural signalling with generally slower blood-borne hormonal action.
Mapped to the named 0654 section using teaching from the corresponding single-science course. A 0654-specific review of every Core and Supplement objective is still in progress. Written practice is self-checked; it does not demonstrate supervised laboratory competence or award an official Cambridge grade.
Before you begin
- Recall electrical impulses, blood transport, gland secretion and the distinction between a stimulus and a body response.
Work on paper. Try each question before revealing help, and explain why your method works.
Quick readiness check
Which quantity describes speed of action here?
What you will learn
- Compare the onset of a response
- Use a general contrast without an absolute rule
Compare nervous and hormonal control by speed of action
Speed compares response onset. Nervous action is generally faster; hormonal action generally slower, with relatively rapid hormonal examples. Original teaching model.
| Feature | Meaning |
|---|---|
| Speed | Time until response begins |
| Nervous | Generally faster onset |
| Hormonal | Generally slower onset |
| Qualification | Adrenaline can act relatively rapidly |
Compare the onset of a response
Speed of action concerns how quickly a response begins after the relevant signal. Nervous control is generally rapid: electrical impulses travel along neurones to coordinate effectors. Hormonal control is generally slower because a chemical released by a gland must be transported in blood and act on responsive targets. This is a general comparison rather than one fixed delay for every system.
For a familiar contrast, a simple withdrawal reflex produces a rapid muscle response to a supplied painful stimulus. A hormonal signal often begins more slowly. Keep the comparison matched: say nervous action is generally faster and hormonal action generally slower. Simply describing the nervous system as electrical and hormones as chemical does not directly answer a speed question.
Use a general contrast without an absolute rule
Adrenaline shows why the word generally matters. It can produce relatively rapid hormonal responses, so it would be wrong to claim every hormone needs days before any effect occurs. A fast hormonal example does not make the blood-borne substance an electrical impulse or remove the useful general speed contrast.
If a question supplies measured onset times for two systems, use those times as evidence for that particular comparison. Convert them to the same units before calculating a difference or ratio. A supplied timing record describes the model responses, and is not a universal measurement for all neurones, glands, hormones or target organs.
Sources for this lesson
Pause and explain
Which comparison is accurate?
Worked example
Compare nervous and hormonal speed of action.
Show the worked solution
- Nervous control is generally rapid.
- Hormonal control is generally slower, with relatively fast examples such as adrenaline.
Answer Nervous action is generally faster; hormonal action is generally slower, although adrenaline can act relatively rapidly.
Try a topic test
Choose Easy, Normal or Difficult. Save your answers and open worked review after finishing.
Test this topic →From guided practice to a new situation
Write your answer and reasoning first. Use a hint only if you are stuck. The model solution is for self-checking; your written work is not automatically marked.
Compare the speed of nervous and hormonal control.
Give me a hint
State both sides of the timing contrast.
Compare my reasoning
- Nervous control is generally rapid.
- Hormonal control is generally slower.
Nervous control is generally faster; hormonal control is generally slower.
Look for these in your work
- Compare both systems
- Use speed rather than duration
Why is every hormone takes days an unsuitable rule? Use the taught example.
Give me a hint
A general comparison allows differences between hormones.
Compare my reasoning
- Adrenaline can act relatively rapidly.
- Hormonal signalling still uses a chemical carried by blood.
Adrenaline can have relatively rapid effects, so a universal days-long delay is false. It remains a blood-borne chemical hormone.
Look for these in your work
- Use adrenaline as a counterexample
- Retain the hormone route
A supplied neural response starts at 0.5 s and a hormonal response at 20 s. Compare onset, keeping the conclusion specific to these responses.
Give me a hint
Both values are already seconds.
Compare my reasoning
- 20 − 0.5 = 19.5 s later for the hormonal response.
- The neural response begins sooner in this record.
The neural response starts sooner; the hormonal response starts 19.5 s later in this supplied record. These are not universal system delays.
Look for these in your work
- Use onset values and units
- Keep the comparison evidence-bound
Common mistakes
- Saying every hormone always takes days.
- Answering only duration when asked for speed.
What can you explain now?
Which comparison is accurate?
Compare with the explanation
Nervous action is generally faster; hormonal action generally slower
It preserves the useful contrast without an absolute timing rule.
After trying it yourself, choose your next review. This is your self-assessment.
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Make it stick
Compare onset speeds without claiming every hormone has the same delay.
If you needed the solution, close it and solve the problem again from a blank page. A correct answer is stronger when you can explain the reason for each step.