Introduction to the Peripheral Nervous System - Video Tutorials & Practice Problems

Peripheral Nervous System

Hey everyone and welcome to the peripheral nervous system. Now, as you may remember from quite a few videos back now, the peripheral nervous system represents all neural structures outside of the CNS. So the CNS is of course the brain and spinal cord and then the peripheral nervous system, the PNS is pretty much everything else. So the PNS has the very important task of making us aware of the world around us and helping us actually navigate it. So it's going to be sending all kinds of information up to the central nervous system and then actually carrying out the actions that the CNS wants us to do. So, the PNS is comprised of several different components. First, we have sensory receptors, it also contains afferent and efferent nerves and their associated ganglia. And you guys remember ganglia from a while back, right? Those are just clusters of neuron cell bodies that exist outside the CNS. So in the PNS and an easy way to kind of remember the difference between afferent and efferent nerves is that affluent nerves facilitate the arrival of a signal to the CNS. So afferent arrival. So in other words, this is the PNS sending information up to the central nervous system and then efferent nerves facilitate the exit of a signal from the CNS. So efferent exit. So that is basically the central nervous system sending commands or information down to your peripheral nervous system. And then finally, we also have motor endings. Now we're going to cover all of these more to um all of these topics in more detail in upcoming videos. So don't worry too much about the nitty gritty of each of these for now, just know that these are the components that make up the peripheral nervous system. All right. So scooching down to our figure here, we have this cute little person and we can see we have the central nervous system depicted in purple. We have our brain and our spinal cord there and then all of these little pink nerves make up the peripheral nervous system. And we have this little cartoon for you here to kind of showcase how the central and peripheral nervous systems work together and kind of what their relationship is like. So if you can imagine a scenario where you're holding a match and the flame is getting a little too close to your skin, it's getting a little dangerous. What's going to happen is that sensory receptors in your skin are going to sense that heat and then your peripheral nervous system will send signals up to your CNS using your ent division, right? Those signals will arrive in the brain. And your PNS is basically saying, hey, we're sensing too much heat in the hand. This is not going good and then your central nervous system will make the executive decision. All right, we're going to move the hand and then what's going to happen is those commands will get sent down to the peripheral nervous system through those efferent fibers, they will exit the brain and go down to your PNS And we'll actually see movement will drop the match or whatever needs to happen. So that's kind of what the relationship between these two systems is like the CNS is in charge. The PNS is kind of like the the little soldier carrying out all of those necessary actions. All right. So that is the peripheral nervous system in a nutshell. And I will see you guys in our next video to talk about some of these systems in a bit more detail. See you there.

Introduction to the Peripheral Nervous System Example 1

Hey there. So this example is asking us which of the following does not require use of the peripheral nervous system. So as a reminder, the peripheral nervous system is going to be sending information to our brain about our internal and external environment, all that sensory information and then it's going to be carrying out the motor activity that our brain wants to happen. So looking at these choices, I can see a raising your hand in class is a motor activity that would be our PNS. So we want what is not requiring the PNS? So A is out B thinking about the answer to a problem. Now that is cognitive, right? So that would just be your CNS. So B is looking promising, but we'll kind of just underline it for now. C is clicking on the correct answer to a problem that's motor activity. And then D is feeling the warmth from a cup of coffee that is a sensation that is coming from our PNS. So our answer is indeed B thinking about the answer to a problem would not require the PNS. That would be a purely CNS driven activity. All right, see you guys in our next one. Bye bye.

Which of the following structures can be found in the afferent division of the PNS?

• A. Sensory receptors.
• B. Motor endings.
• C. Motor neurons.
• D. Skeletal muscles.