100,000 miles of Brain Wiring

Estimates are that the human body contains 60,000 to 100,000 miles of blood vessels and 250,000 miles of lymph vessels, depending on the size of the individual. Estimates are that a network of some 100,000 miles of nerve fibers, called white matter, connect the various components of the mind. Diffusion Spectrum Imaging has shown that the nerve fibers are all grids and intersect at right angles like the lines on a sheet of graph paper. Each neuron is a distinct cell separate from every other neuron. Neurons send signals along axons. A tiny gap separates the ends of axons from dendrites, the receiving ends of neurons. Human neurons have on average 10,000 synapses.

(Zimmer, Carl. “Secrets of the Brain.” P 36-45, National Geographic, February 2014. Washington DC:National Geographic Society.)