+
4 Tutorials that teach Neurons: Communication
Take your pick:
Neurons:  Communication

Neurons: Communication

Description:

This lesson will describe the process of neuronal communication as neural impulses generated and transmitted from one neuron to another.

(more)
See More
Try a College Course Free

Sophia’s self-paced online courses are a great way to save time and money as you earn credits eligible for transfer to over 2,000 colleges and universities.*

Begin Free Trial
No credit card required

25 Sophia partners guarantee credit transfer.

221 Institutions have accepted or given pre-approval for credit transfer.

* The American Council on Education's College Credit Recommendation Service (ACE Credit®) has evaluated and recommended college credit for 20 of Sophia’s online courses. More than 2,000 colleges and universities consider ACE CREDIT recommendations in determining the applicability to their course and degree programs.

Tutorial

What's Covered

In this tutorial you will learn about neurons. Specifically you will focus on:

  1. Neuron Communication


1. NEURONS COMMUNICATION

The nervous system, which is your brain and your neurons, and all the nerves that go throughout our bodies, acts as the body's communication system. It sends information to and from the brain, and allows you to control the rest of your body in different kinds of ways.

Think About It

There are two different ways that a neuron communicates, and that's within the neuron itself-- within one individual neuron-- as well as between different neurons. Today, you're going to be taking a look at that message that's being sent inside of one neuron.

The process starts at the dendrites, which are the long, tree-like branches that extend from the cell body itself. What these dendrites do, is they collect different kinds of messages from other neurons surrounding it.

It doesn't necessarily do anything until it reaches a certain level of messages. So one message doesn't cause it to communicate its information; it has to be a combination of lots of them. This is what we call the "Threshold of Excitation." Which is to say, the level, or the point at which the neuron is caused to fire, or a neural impulse is triggered.

Looking more closely at the axon, which is that tail like structure that extends off of the cell body, and acts as a sender or a transmitter of information. The axon is actually covered in all these tiny little holes or tunnels, or what are called "ion channels." What the ion channel does is allow the cell to control or pump the amount of ions, either inside of the cell, or outside of the cell.

Term to Know

Ion Channels

Small tunnels along a neuron that to pump ions from one side of the cellular membrane to the other, which creates an electrical charge.

More importantly, an ion is a positively or negatively charged atom.

ExampleSo when the cell pumps a certain amount of sodium, let's say, which is Na, outside of the cell, and potassium inside of the cell, these electrically charged ions create a charge across the entire axon. And at a resting potential, which is when a cell is not firing-- in other words, when it's sitting and it's waiting to fire, or send a message-- the sodium is generally concentrated outside of the cell. And there's more potassium inside of the cell.

Term to Know

Resting Potential

The state in which a neuron is not firing or sending a neural impulse and when there is a negative electrical charge inside the neuron.

When the neuron receives a message from the dendrites-- enough to reach that threshold of excitation- - when it reaches that point at which it's going to fire, then the cell switches from a resting potential to an action potential. 

And this is when it sends that neural impulse; it fires. What that means is that these ion channels all of a sudden throw themselves open, and the Na, the sodium, comes rushing inside of the cell, and the potassium comes outside of the cell afterwards. 

Term to Know

Threshold of Excitation

The level or point at which a neuron fires, or a neural impulse is triggered.

As a result of this process, it creates more of a positive charge inside the cell, and then a negative charge outside of the cell. And this then allows for a sort of domino effect, where these channels open up and create that switch of electrical charges. 

Eventually the ones next to it also throw themselves open, and send sodium and potassium outside and inside of the cells. And then it continues to go all the way down the axon, until it reaches that axon terminal, that button at the very end of the cell.

When a a neuron fires, this is an all-or-nothing reaction. Either it fires completely and throws open all of these ion channels, or doesn't fire at all. So there's no partial, it's just like a light switch (e.g., on or off). And these neural impulses, these action potentials, can move very quickly; so they're fast, but they're not necessarily instantaneous. Which is why it takes a split second for us to react to something in our environment.

Term to Know

Action Potential

The state in which a neuron reaches its Threshold of Excitation and fires, or sends an electrical impulse down the axon.

After this occurs, after all of this exciting action potential happens, the cell then resets. Essentially the ion channels pump the potassium back inside the cell, and the sodium back outside of the cell. And it resets itself, and gets ready to fire again; and so it goes back to a resting potential. And that is how the information is sent. That electrical charge is created that goes all the way across a neuron, and gets ready to send information to other areas and other neurons that are attached to.


Summary

This tutorial discussed neurons, specifically focusing on neuron communication. It's important to remember that there are two ways for neurons to communicate: within the neuron itself-- within one individual neuron-- as well as between different neurons.

Keep up the learning and have a great day!

Source: This work is adapted from Sophia author Erick Taggart.

TERMS TO KNOW
  • Action Potential

    The state in which a neuron reaches its Threshold of Excitation and fires, or sends an electrical impulse down the axon.

  • Ion Channels

    Small tunnels along a neuron that to pump ions from one side of the cellular membrane to the other, which creates an electrical charge.

  • Resting Potential

    The state in which a neuron is not firing or sending a neural impulse and when there is a negative electrical charge inside the neuron.

  • Threshold of Excitation

    The level or point at which a neuron fires, or a neural impulse is triggered.