Physics and the heart

[Kateena]

Hey everyone!

This is not exactly a homework question, but i would like to know anyway.. can anyone tell me how the heart works from physics point of view? Or the nervous system?

Any points would be great :)

thanks!
kateena

[Motifs]

People, Be quiet ! I ain't no biologist !
Hah, Here, biological tracks, I guess my friend Kateena should look into some books on the topic of biomechanics for sufficient help.
I once saw a lot of them, but :redface: in my school library. Your school should have much more than mine.

[Claude Bile]

When our heart is working normally, it pumps fairly regularly, though it does change (when we exercise for example). It keeps its regularity through the use of feedback in the form of nerve signals.

When the purturbations on the heart are small, the feedback serves to regulate the heartbeat. However if the purturbation is large enough, for example due to a blocked artery, the feedback will no longer regulate the system and the heartbeat will become aperiodic and then finally chaotic. When the heart beats chaotically, it no longer pumps blood through the body. Medically it is called a myocardial infarcation, but it is commonly called a heart attack.

This is why heart attacks are caused by things such as blocked arteries, excess blood loss etc, anything that causes massive change in the blood flow of the body. High blood pressure and heart rate has the effect of magnifying any perturbations, which is why they are such high risk factors when it comes to heart attacks.

The descent from periodicity into chaos is actually observed in a huge variety of systems, not just heartbeats. There are many textbooks on chaos, also a quick web search should also yield some good information.

I'm not sure if that is what you were looking for, but I hope you find it interesting nontheless.

Claude.