Rigor Mortis

I learned something new today.

Rigor mortis, that stiff feeling the dead people always get, is caused by the decrease of ATP molecules in the blood which is needed to relax muscle contractions.

Muscle contractions are triggered by calcium ions when it comes to contact with muscle fiber.

When people stop breathing (or die), there is little oxygen available to produce ATP, hence the ATP concentration drops. Likewise, with no blood circulation, there is continuous migration of calcium from the skeleton out to the blood and eventually to the muscles.

Because the calcium will contract the muscles and there's a shortage of ATP to relax them, dead bodies end up stiff.

Seems like I can become a CSI soon.