Neurons and the
Action Potential
Rosa Caballero
Insulating the axons
AIn many axons, action-potentials move along reasonably well, but not very fast. In others, action potentials really do skip along the nerve.
The action-potential
The answer hinges on harnessing energy locked in physical and chemical gradients, and coupling together these forces in an efficient way.
The dynamic neuron
As we described in the last chapter, a neuron consists of dendrites, a cell body, an axon and synaptic terminals.
This structure reflects its functional subdivision into receiving, integrating and transmitting compartments.
Neurons and the
Action Potential
Whether neurons are sensory or motor, big or small, they all have in common that their activity is both electrical and chemical.
Receiving and deciding
On the receiving side of the cell, the dendrites have close contacts with incoming axons of other cells, each of which is separated by a miniscule gap of about 20 billionths of metre.
A dendrite may receive contacts from one, a few, or even thousands of other neurons.