The Nervous System
The nervous system detects stimuli and coordinates a rapid response using electrical impulses carried by neurones.
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The nervous system detects stimuli and coordinates a rapid response using electrical impulses carried by neurones.
- Brain and spinal cord form the CNS
- Receptors detect stimuli
- Effectors are muscles or glands
🧠 Quick quiz
Three questions. Score 2 or more to complete the topic.
What is The Nervous System?
Within Biology, which covers cells, the human body, genetics, evolution, plants and ecosystems: the science of living things, this topic explains The Nervous System. Biology topics show how living things work, from the cell up to whole ecosystems, with models you can explore step by step.
Check that you can explain The Nervous System in your own words and give one example from everyday life. If you can do that, you have understood the core idea.
Understanding The Nervous System helps you explain how living things stay alive and respond to their surroundings, which is central to biology exams.
The Nervous System in detail
The nervous system lets an organism detect changes and respond. The central nervous system (CNS) is the brain and spinal cord, and the peripheral nerves link them to receptors and effectors. Sensory neurones carry impulses from receptors to the CNS, relay neurones link them within the CNS and motor neurones carry impulses to effectors (muscles or glands).
Neurones carry electrical impulses, and at the synapse, the gap between neurones, chemicals called neurotransmitters carry the signal across. Signals travel very fast, allowing quick responses. Receptors include those in the eye, ear, skin, tongue and nose.
How the interactive helps you understand The Nervous System
Click a step, or use the Previous and Next buttons, to move through the sequence one stage at a time. Auto-play moves on for you.
Before you change anything, predict the result. Then change one value at a time and check whether your prediction was right. This is a quick way to build a correct mental model of The Nervous System.
Real-life uses and examples
- Use The Nervous System to interpret a diagram, graph or microscope image from a practical.
- Structure a longer answer about The Nervous System by moving from definition to example to consequence.
- Explain how The Nervous System helps a living thing stay alive, using a plant or animal example.
Common mistakes to avoid
- Using everyday words, such as “energy” or “bad”, without their scientific meaning.
- Listing the steps of a process without saying how one step causes the next.
- Learning the definition without testing it. Use the quiz and the interactive to check that you can apply the idea.
Frequently asked questions about The Nervous System
What is The Nervous System?
The nervous system detects stimuli and coordinates a rapid response using electrical impulses carried by neurones.
What are the most important points about The Nervous System?
The main points are: Brain and spinal cord form the CNS; Receptors detect stimuli; Effectors are muscles or glands.
Why is The Nervous System useful?
Understanding The Nervous System helps you explain how living things stay alive and respond to their surroundings, which is central to biology exams.
How can I practise The Nervous System?
Open the interactive at the top of this page and change the controls one at a time. Predict the result before each change, then take the three-question quiz. A score of two or more marks the topic as complete on this device.
Which topics are related to The Nervous System?
Related topics in Biology include The Brain, Homeostasis, The Skeleton and Joints.