Wednesday, November 27, 2013
Your Synapses and Neurons #1
Most people now know the term neuron (nerve cells in the brain, spinal cord, and peripheral nervous system) that have a special ability to talk with each other. They hold these conversations throughout a vast and intricate network. Estimates are that your brain alone contains about 100 billion neurons (and that there are thousands of neurons in your heart and at least a million in your intestines, and so on). These 100 billion neurons connect with each other via a quadrillion connections known as synapses (the tiny space between each neurons). The book Super Brain describes it this way: neurons project wormlike threads known as axons and dendrites, which deliver both chemical and electrical signals across the space between synapses. A neuron contains many dendrites to receive information from other nerve cells. But it has only one axon, which can extend out to over a meter (about 39 inches) in length. An adult human brain contains well over 100,000 miles of axons and countless dendrites--enough to wrap around the earth over four times. Wow!