In our series of posts about online study skills, we had frequent occasion to from Nicholas Carr’s fascinating book The Shallows. In the book Carr gives a succinct and extremely helpful summary of how the human brain operates.
“[discrete nerve cells]—our neurons—are both like and unlike the other cells in our bodies. Neurons have central cores, or somas, which carry out the functions common to all cells, but they also have two kings of tentacle-like appendages—axons and dendrites—that transmit and receive electric pulses. When a neuron is active, a pulse flows from the soma to the tip of the axon, where it triggers the release of chemicals called neurotransmitters. The neurotransmitters flow across [the] contact barrier—the synapse, we now call it—and attach themselves to a dendrite of a neighboring neuron, triggering (or suppressing) a new electric pulse in that cell. It’s through the flow of neurotransmitters across synapses that neurons communicate with one another, directing the transmission of electrical signals along complex cellular pathways. Thoughts, memories, emotions—all emerge from the electrochemical interactions of neurons, mediated by synapses.”