How long will a living human heart keep beating after you slice it out?

We dissected a fetal pig, but that was already dead, thankfully.

As for the frog, our teacher made us form groups of two, and each group got to choose a live victim from a tank of leopard frogs. We had to stun it first by whacking its head against the side of a desk (luckily we had the choice to do it ourselves or let the teacher do it for us – most of us chose the latter).

Interesting day…

Huh. All the movies I’ve ever seen used chloroform…was the classroom out of cotton balls or something, or did E.T. lie to me? :eek:

We pithed ours.



If the heart was still beating then the frog was alive when they cut into it, then yes, that is exactly what “vivisection” means.

We did “dissection” in highschool. The frogs were very dead when they were given to us.

Wouldn’t you need a frog heart for that?

The frogs are actually brain-dead when they are dissected. Merely having a beating heart is not accepted as being “alive” in the case of humans; most people accept that a brain-dead person is actually dead even if the heart is still pumping. Those frogs are just as dead as that.

And if you want to define “vivisection” as cutting into any animal while its heart is beating, then an awful lot of procedures vetinarians do every day qualify.

Originally Posted by Sigene
Let’s see…


I’d have expected hat from CandidGamera. :smiley:

Ah, I see. I misunderstod the procedure and thought they were somehow only anesthetized. Out of curiosity, how are they rendered brain dead?

We never had brain dead frogs in school, only pickled frogs.

Lots of different ways. For muscle physiology experiments pithing is quite common. Basically you shove a nail into the spinal column in the next and jam it into the skull and scramble the brain. Fast, painless and minimal disruption of non-brain-related processes.

For less delicate work you can simply crush the skull with a steel bar. Swinging the animal into a benchtop is a variation of this, though much less certain and definitely not recomended by any ethics borard Ive ever heard of. Or you can drive a knife into the skull behind the eyes and through the brain. At the extreme you can decapitate the animal, which one lab I visited did using a standard paper guillotine.

Or you can use a range of poisons including chloroform. These however have an unfortunate side effect that if the dose is even slightly too strong the heart muscle itself is poisoned and stops functioning. That’s why mechanical methods are preferred for physiology experiments.

Howdy. I’ve lurked here for years, but after reading this thread I had to register. The below link might give some insight into how long a human heart can keep functioning when its original owner has ceased to do so. If not, it’s still a fascinating read. WARNING: May be disturbing to the squeamish.

Why wouldn’t this severe brain damage kill the frog? (I’m just thinking of the spear-gun type things they use to kill cattle in abbattoirs.) Wouldn’t a nail to the brain cause enough damage to end vital functions too?

(Um, please pardon the hijack.)

Funny, what brings people in. That’s an incredible story. Thanks for the link

And welcome in, of course

I does kill the frog, that’s the whole point. You can’t ethically do dissections on conscious animals, and anaesthetising is a waste of time and resoucres as well as terribly complicated. So you kill the animal by scrambling its brains. No pain, no mess, no damage to any other part of the body.

However a frog’s brain is primarily a coordination centre, it doesn’t have much to do with vital functions, or even non-vital ones. Those are endogenic or else run on reflex arcs from the spinal cord. By inserting the pithing needle high up in the spinal cord all those functions remain intact. A pithed frog doesn’t ventilate its lungs or blink because those things are controlled by the brain. However it will right itself if you turn it on its back and it will scratch itself if you place a drop of acid on its skin because those behaviours are controlled from the spine. And the heart keeps beating just fine because the rhythm is set internally while the controls are largely modulated by the spine.

Well, I thought so. I had some interesting times as a volunteer EMT, but that story…damn.

My pleasure.