Homeostasis and ResponseAQA GCSE Biology (8461)

The Human Nervous System

Work through the notes, try the practice questions, then take the quiz. The report tells you exactly what to revise next. (2026)

Practice progress

5 MCQs

0 of 5 attempted

Correct

Incorrect

Remaining

1
Which structures make up the central nervous system?
Answer & explanation
Correct: option A
CNS = brain + spinal cord. Peripheral nerves are separate.
2
Which neurone carries impulses FROM the CNS TO an effector?
Answer & explanation
Correct: option C
Motor neurones carry impulses OUT of the CNS to muscles or glands (effectors).
3
How does a signal cross a synapse?
Answer & explanation
Correct: option C
Neurotransmitters are released into the synapse, diffuse across, bind to receptors and trigger a new impulse in the next neurone.
4
What is the correct order of a reflex arc?
Answer & explanation
Correct: option B
Order: stimulus → receptor → sensory → relay → motor → effector → response.
5
Why are reflex actions so fast?
Answer & explanation
Correct: option B
Reflexes bypass the conscious brain, so the pathway is shorter and the response is much faster.

Homeostasis and ResponseAQA GCSE Biology (8461)

Work through the notes, try the practice questions, then take the quiz. The report tells you exactly what to revise next. (2026)

5 MCQs

0 of 5 attempted

Correct

Incorrect

Remaining

1
Which structures make up the central nervous system?
Answer & explanation
Correct: option A
CNS = brain + spinal cord. Peripheral nerves are separate.
2
Which neurone carries impulses FROM the CNS TO an effector?
Answer & explanation
Correct: option C
Motor neurones carry impulses OUT of the CNS to muscles or glands (effectors).
3
How does a signal cross a synapse?
Answer & explanation
Correct: option C
Neurotransmitters are released into the synapse, diffuse across, bind to receptors and trigger a new impulse in the next neurone.
4
What is the correct order of a reflex arc?
Answer & explanation
Correct: option B
Order: stimulus → receptor → sensory → relay → motor → effector → response.
5
Why are reflex actions so fast?
Answer & explanation
Correct: option B
Reflexes bypass the conscious brain, so the pathway is shorter and the response is much faster.