How Do Your Nerves Work?


 

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the action potential cycle of a nerve

So how does a sensation travel from you nerve sensors to the brain and back? Well the information passes in an impulse that travels down/up the nerve. The impulse movement is based entirely on the actions of positively charged sodium and potassium ions.

The nerve cell has three states: resting potential, repolarization, and depolarization. The resting potential is when there is no impulse travelling through the nerve cell; at this time it holds more positively charged sodium ions outside the cell membrane and more negative ions within. When a message is passed from the previous cell ion, the cell receives a rush of positive sodium ions with is called depolarization. This causes the cell to respond by repolarizing and a charge of positive potassium ions flows in the opposite direction, returning the cell balance back to its resting potential. The depolarization and repolarization triggers the same occurrences in the next cell and the impulse is sent down a neuron like a wave (Allen, et al., 2007).

When an impulse comes to the end of one neuron and the beginning of another there is a small space called a synapse or synaptic cleft. The impulse prompts the release of neurotransmitters that cross the synaptic cleft between the two neurons. This transfer of neurotransmitters can either trigger a new impulse or actively inhibit the impulse from firing (Allen, et al., 2007).

The Synapse Between Two Neurons

So what happens at the synapse between two neurons?

close up of the synapse between two neurons

  • The sending, or presynaptic, neuron synthesizes the neurotransmitters based on the strength and type of information sent along on the impulse
  • If the message is to be sent to the next neuron in the chain, the action potential travels down the sending neuron and brings the neurotransmitters to the axon terminal, which is the end of the sending neuron right at the synaptic cleft.
  • As the action potential reaches the presynaptic terminal, it releases calcium into the cell; this causes the generated neurotransmitters to be released into the synaptic cleft
  • The neurotransmitters travel across the synapse and attach to receptors in the receiving, or postsynaptic, neuron; this influences the action of the postsynaptic neuron.
  • The neurotransmitters disconnect from the receptors and, occasionally, turn into inactive chemicals that are reabsorbed. If enough neurotransmitters are received to cause a response in the postsynaptic neuron, it triggers another action potential that carries the impulse to the next neuron
  • Unused neurotransmitters that are left over in the synaptic cleft are reabsorbed by the presynaptic neuron and recycled(Kalat, 2004).

Keeping Healthy to Play Safe

If you sustain permanent damage to your nerve endings you can loose feelings in those parts of your body. This can increase the risk of engaging in kink and fetish play. Some forms of BDSM play have a small window of safety and your risk of serious injury goes up if you are too slow to respond to danger because your nerve endings have lost sensation. Take care of your body and ensure that you always play safe.

Written September 4, 2011 | Updated April 28, 2015
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Article References

Allen, M., Bagg, A., Hamilton, J., John, K., Fricker, J., de Burgh, J., et al. (2007). The Human Body Book. New York: DK Publishing.

Kalat, J. W. (2004). Biological Psychology 8th Edition. Toronto: Nelson Thomson Learning.

Image References

Someone else's art deserves recognition! The images presented in this article were borrowed from the following places:

Header Image: http://baef480c1b9a59094802-bb7fd020772cbf1cd099f3b22c712b0b.r79.cf2.rackcdn.com/f4bad255cb49b95b3ee31500b7d40023.jpg | Retrieved April 28, 2015

Image 1: Allen, M., Bagg, A., Hamilton, J., John, K., Fricker, J., de Burgh, J., et al. (2007). The Human Body Book. New York: DK Publishing.

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