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.
Axons are extended regions of the neuron cell membrane. It starts from a portion of the cell body, known as the axon hillock. From there, the axon extends towards the target cell to what is known as the terminal. Along the cell membrane of the axon will be ion channels and ATP-driven pumps that will regulate ion concentrations within the axon.