Why is autonomic tone a significant part of ANS function?

Question

Accepted Answer

Hi, everyone. Let's take a look at our next question. Which of the following statements concerning the autonomic tone is false. A it is an important aspect of A NS function just as muscle tone is a key aspect of SNS function. B is the inactivity of the sympathetic or parasympathetic motor neurons under resting conditions. C it allows for an increase or decrease in the activity of automatic motor neurons thus providing a greater range of control options. And D it is significant where dual innervation occurs and even more interpretation, more important. Excuse me, where dual innovation does not occur. So first of all, we need to remember what autonomic tone is. As you can tell from the name, it has to do with the autonomic nervous system. And it's the background level of activity of the SNS and PNS motor neurons under resting conditions. So when no activity is going on, the body is just in this quiet state, what's that background level of activity? So with that in mind, let's evaluate our answer choices. Remembering that we're looking for the false statement. Choice says it is an important aspect of A NS function just as muscle tone is a key aspect of SNS function. And this is true to understand how the autonomic nervous system is being affected by certain things, whether stimuli or signals from the brain, you'd need to know what the background level is. What's the resting condition to understand how it will change. So choice, a definitely a true statement and therefore not her answer. Choice. B it is the inactivity of sympathetic or parasympathetic motor neurons under resting conditions. Well, this here is our answer because it is not inactivity, it's the background level of activity. So that's very different because an autonomic nervous system where it's controlling all these essential functions for keeping the body alive, breathing heart rate, blood pressure, there's not a lot of nerves that are going to be inactive even in resting position. So we found our answer. But to be thorough, we'll just keep going here. Choice C says it allows for an increase or decrease in the activity of autonomic motor neurons thus providing a greater range of control options. Well, this would not be the case if the neuron state at rest is completely inactive because then all you can do is turn on activity. But as we discussed in the A NS, not too many of those neurons will be completely inactive at rest, something will be going on and so that something can be adjusted up or down depending on the situation that provides a greater range of control options. So this is true and therefore not our answer. And finally choice d it is significant where dual innovation occurs even more important where dual innovation does not occur. Let's recall what dual innovation is. And this is when and of course, dual innervation is when a neuron receives signals from both the sympathetic nervous system and the parasympathetic nervous system. Now, as you can expect, given that the sympathetic nervous system is our fight or flight response, parasympathetic is rest and digest these two systems often have opposing effects. So you'd need to know that and understand the background level of activity before you could predict the way they interact it. So that's why it's important to understand what autonomic turn autonomic tone is when you have dual innovation, but even more important when you don't have dual innovation because then the autonomic tone is completely responsible for whatever the resting level of activity is. And then you would need to understand this to see just how it gets adjusted and fine tuned. So to d also true statement and therefore not our answer. So once again, the false statement here about the autonomic tone is choice B it is the inactivity of the sympathetic or parasympathetic motor neurons under rest under resting conditions. See you in the next video.

Why is autonomic tone a significant part of ANS function?

Key Concepts

Autonomic Tone

Sympathetic and Parasympathetic Balance

Homeostasis and Physiological Regulation

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