What Happens To Your Body After You Die

After that, your body will tense up

Rigor mortis sets in after death, causing all of the muscles to contract and stiffen. Forensic pathologist Judy Melinek says it's caused when your body runs out of a certain chemical."Rigor mortis, or stiffening of the muscles after death, occurs from depletion of adenosine triphosphate (ATP), the chemical in our muscles necessary for relaxation of the muscle fibers after a contraction," she said. "ATP is produced metabolically by muscle cells and forces your muscle’s contractile units to disengage. When you stop breathing, your cells stop producing ATP. The microscopic fibers lock up, and your muscles stiffen.”It usually starts in your face in the first four hours after death, and reaches your larger muscles within twelve hours.Your muscles won't start to relax again until a few days later when they start to decompose.