Sodium is the first ion to enter the axon, initiating the action potential.
A nerve impulse typically starts at the dendrites of a neuron, where it receives signals from other neurons or sensory receptors. These signals are then transmitted down the axon of the neuron to the axon terminals, where they can communicate with other neurons or target cells.
the diameter of an axon
synaptic vesicles
Its main function is to propagate the action potential (the 'impulse') along the length of the axon.
cell body, continues down the axon, and finally reaches the axon terminal. At the axon terminal, the impulse triggers the release of neurotransmitters to communicate with other neurons or muscles.
Via chemical messangers that cross the synapse.
axon
Curently unknown...
The material surrounding the axon that increases the speed of the nerve impulse is called myelin. Myelin is a fatty substance that acts as an insulating layer, allowing for faster transmission of electrical signals along the axon.
One factor that does not influence the rate of impulse propagation is the size of the neuron. The rate of impulse propagation is determined mainly by the myelination of the axon, the presence of nodes of Ranvier, and the diameter of the axon.
This is called saltatory conduction.
myelin