Dr. Andy Galpin

That's probably going to turn over.

You will have all new skin cells every 30 to 50 days or something like that.

Red blood cells, maybe more like every 120 days.

And skeletal muscle can actually have a lifespan of maybe a decade or something like that, maybe a little bit longer.

But your heart tissue is going to very rarely turn over.

It's not meant to be hyperplastic.

That does not mean it doesn't respond and adapt and change to stimuli like high blood pressure, like exercise.

It absolutely does.

But it happens much slower.

That's not the primary job.

So the fibers themselves are shorter, they are nice and thick, and they have a single nuclei.

But they have a couple of actual special unique advantages that skeletal muscle does not have.

For example, they are connected to each other through what are called intercalated discs.

Now, these are specific and unique to cardiac tissue.

And what actually allows to happen is for there to be what's called gap junctions.

So there's almost little entry points from one of the fibers to the next one.

And what that does is it gives the ability...

for an action potential, which is the electrical voltage that goes into the fiber that causes it to contract.

It allows that voltage to leak from one fiber to the next.

You wouldn't want this in your skeletal muscle because that means when you contract one fiber or set of fibers,