The structure of the human brain is enormously complex. It contains about 10 billion nerve cells (neurons), which are interlinked in a vast network through 1,000 billion junctions (synapses). The whole brain can be divided into subsections, or sub-networks, which communicate with each other in a network fashion. All this results in intricate patterns of intertwined webs, networks of nesting within larger networks.

The Web of Life: A New Scientific Understanding of Living Systems (ed. Doubleday, 1996)