Psychology 9-1 GCSE - 

4.1.3 - Know what neurons and synapses are, including:

a) Function of neurotransmitters - 

Neurotransmitters are electrochemical messengers that transmit nerve inpulses across the synaptic gap during the process of synaptic transmission. Some are excitory and some are inhibitory. Excitory neurotransmitters make the post synaptic cell more likely to fire. While the inhibitory neurotransmitters make them less likely to fire.

b) Synaptic functioning - 

Synapses are the junction between neurons. Communications flow via this.

c) How neurons and synapses interact - 

, usually in the form of neurotransmitter molecules secreted by the presynaptic neuron that travels a short distance across the synaptic cleft, this is the actual space between the neurons. Once at the post synaptic neuron, some of the neurotransmitters will attach themselves to some receptors.

d) Understand the role of the central nervous system - 

The central nervous system (CNS) consists of the brain and the spinal cord. The spinal cord connects to the brain via the brain stem and runs down through the spinal canal inside the vertebra. The spinal cord carrys information from various parts of the body to and from the brain. In the case of some reflect movements the responses are controlled by the spinal pathways without the brains involvement.