A columnist is someone who writes for publication in a series, creating an article that usually offers commentary and opinions. Columns appear in newspapers, magazines and other publications, including blogs. They take the form of a short essay by a specific writer who offers a personal point of view.
This positive spike constitutes the action potential: the electrical signal that typically moves from the cell body dlown the axon to the axon terminals. The electrical signal moves down the axon like a wave; at each 84 Ch apter 3 Biopsycholo gy point, some of the sodium ions that enter the cell diffuse to the neJ1.'t section of the axon, raising the charge past the threshold of excitation and triggering a new influx of sodium ions.
axon. the process of a nerve cell along which impulses travel away from the cell body. It branches at its termination, forming synapses at other nerve cells or effector organs. Many axons are covered by a myelin sheath formed from the cell membrane of a glial or Schwann cell.