The Nervous System — Structure and Function

This lesson covers the structure and function of the human nervous system as required by the AQA GCSE Combined Science Trilogy specification (8464). You need to understand how the nervous system detects stimuli, transmits electrical impulses, and coordinates rapid responses.

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Overview of the Nervous System

The nervous system enables humans to react to their surroundings and coordinate their behaviour. It does this by transmitting electrical signals (nerve impulses) extremely quickly along specialised cells called neurones.

The nervous system is divided into two main parts:

graph TD
    A["Nervous System"] --> B["Central Nervous System (CNS)"]
    A --> C["Peripheral Nervous System (PNS)"]
    B --> D["Brain"]
    B --> E["Spinal Cord"]
    C --> F["Sensory Neurones"]
    C --> G["Motor Neurones"]

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The Central Nervous System (CNS)

The CNS consists of the brain and the spinal cord. It acts as the body's coordination centre:

• It receives information from receptors via sensory neurones.
• It processes and integrates the information.
• It sends instructions to effectors via motor neurones.