Nerve Impulse Research Paper

A nerve impulse can also be called an action potential. Each action potential has the same speed and strength, but the frequency of the impulse is what allows the brain to translate these messages and understand the location and importance of what is being communicated. When looking at a resting neuron, the outside of the neuron has a positive charge because of the many Na+ ions in the environment. Inside the neuron, there are K+ ions, which also have a positive charge, but because there are also negatively charged proteins and nucleic acids, the inside has less of a positive charge than the outside and is negative, making the neuron polarized. Within the membrane of the neuron, there are ion channels which open in response to certain stimuli

The refractory period, which is before the resting potential is rebalanced by the pump, prevents the action potentials from traveling both ways down an axon at one time due to the neurons inability to respond to stimuli as a result of the imbalance of Na+ and K+ ions. This entire process repeats in a sort of chain reaction down the axon of the neuron until the impulse reaches the synapse, which is the gap between two neurons. When the neuron is depolarized, voltage-gated Ca2+ channels are activated and opened, releasing Ca2+ into the cytoplasm of the presynaptic neuron. This flow of Ca2+ ions causes synaptic vesicles to fuse with the cell membrane and release the chemical messengers (neurotransmitters) which diffuse across the synapse to the postsynaptic neuron from an area of high concentration to low concentration. The protein receptors, located on the dendrites of the postsynaptic neuron then receive the neurotransmitters which act like the stimulus that then converts the signal back to an electrical signal so the action potential can continue to