ABSTRACT
The human brain is a wonder and a mystery. It is a thing of magic, yet it is a concrete object. It is extraordinary – the most complex thing people can imagine. There is nothing in nature that has any parallel. The brain contains billions of cells, known as neurons. The brain contains perhaps 80 or possibly 100 billion neurons. The brain operates by sending messages along pathways between neurons. Each neuron has branches that connect to other neurons. The development of brain imaging has provided amazing insights into the teenage brain. The synapses play a central part in the story, as they can be seen as the on/off mechanism in the brain. Myelin is the substance that covers the axon, and it has two purposes. First, it helps speed up the transmission of a message. It also plays a big role in helping to keep the neurons, axons and dendrites separate from each other.
