Neurons

• There are three types of neurons: sensory neurons, relay neurons and motor neurons
• Sensory neurons are found in receptors -eyes, ears tongue and skin-. They carry messages to the Central Nervous System -CNS-. They have long dendrites and short axons
• Relay neurons are found in the brain and spinal cord; connect the sensory neurons to the motor neurons or other relay neurons. They have short dendrites and long axons
• Motor neurons connect the CNS to effectors such as our muscles or glands. They have short dendrites and long axons
• Excitation increases the chance of the PSN continuing the message to the next neuron as it makes it more likely to fire -e.g. Glutamate-
• Inhibition decreases the chances of the postsynaptic neuron continuing the message to the next neuron as it makes it less likely to fire