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Okay. So the parasympathetic and

the sympathetic systems are commonly known as fight or flight and

rest or digest and, and that's true.

That's true, if we were always at full sympathetic tone or

at full parasympathetic tone.

That's not the case.

Usually, we're somewhere in the middle.

We're bopping over here.

Something happens, a mouse runs by and Tula goes into there.

Tula's been out for four hours, she comes inside.

She eats some crunchiest and, and

good tasty food and now she's down here and she takes a nap.

So moment to moment this is changing.

There is another scale at which our parasympathetic and

our sympathetic tone changes and that is across our life cycle.

So look now we're this is on a showtime scale where we can go sympathetic or

parasympathetic according to the, the needs of the moment.

But as we go from being born to old age,

we are moving in a steady direction towards

more sympathetically dominated.

All right? So

young kids are very parasympathetically dominated.

Their job is to grow, their job is to, to absorb nutrients.

They run around, but their job really is to grow and they do a lot of growing.

Over here, we're sympathetically dominated.

Now there are other conditions, which will

bias an individual towards parasympathetic or sympathetic.

So for instance, very good athletes and

I'm talking very good aerobic athletes are very parasympathetic.

So you can have a 20 year old that's, that's down here.

These, these 20, 30 year olds that were that are cyclists, for instance.

In the old days in the Tour de France these are not steroid cyclists.

These are not.

So they had resting heart rates of about 30 beats per minute.

So that's very, very low.

A normal individual at rest might have a heart rate at around 60 to 70.

So and so that's very low.

So parasympathetic domination is in, in athletes.

Now, once you get to, into older age, if you think about it,

the sympathetic domination is going to drive up heart rate and

it's going to drive up blood pressure.

And what does that sound like?

That sounds like hypertension.

And so this sympathetic activity, this sympathetic tone

iIs probably the reason why individuals go through their entire life,

they're just peachy keen, they reach 50, 60, 70.

And all of a sudden, they have hypertension.

But nothing's changed, except now they're, they're sufficiently sympathetically

dominated that now they're, they've encountered this hypertension.

And in the next segment, we're going to talk about how we can use drugs

that work on the autonomic nervous system to combat things like hypertension.

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Parasympathetic/Sympathetic Balance

Understanding the Brain: The Neurobiology of Everyday Life

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