Neurons and the Brain

• What do we use to think?
• We use our brains.
• How does the brain manage it?
• The homonculus problem.
• The brain is made up of about 500 Billion Neurons
• There are lots of types of neurons, but they all are made up of a body, dendrites and axons.
• Axons from one neuron meet dendrites of another neuron at the synapse (most of the time).
• They vary but neurons have about 1000 post-neuronal synapses.
• When a neuron fires, it sends energy down the axon to the synapse, and along to the next neuron.
• If the next neuron gets enough energy (from all it's pre-neuronal synapses), it'll fire.
• Sensory organs (like your eyes) have neurons that get stimulus from the environment and start the whole chain of action.
• You also have effectors (muscles and organs) that the brain makes go.
• So the brain gets input, categorises it (big world small brain problem), and then decides what to do.
• Short and long term memories.