GCSE Psychology: Neurons and the Nervous System Guide

The nervous system

The nervous system is divided into the central nervous system (brain and spinal cord) and the peripheral nervous system (nerves connecting the CNS to the rest of the body).

Neuron structure

A neuron has dendrites (receiving signals), a cell body, and an axon (transmitting signals to the next neuron), often insulated by a myelin sheath that speeds up transmission.

Synaptic transmission

Information passes between neurons at a synapse, a small gap, using chemical messengers called neurotransmitters, which cross the gap and bind to receptors on the next neuron.

Neurotransmitters

Different neurotransmitters have different effects — for example, serotonin is linked to mood regulation, and dopamine is linked to reward and motivation.

Common mistakes

• Confusing the central and peripheral nervous systems.
• Mixing up dendrites (receive) and axons (transmit) within a neuron.
• Assuming information passes between neurons through direct physical contact rather than across a synaptic gap.