|Signs of death|
Rigor Mortis, the first sign of post-mortem decomposition, literally translates to ‘stiffness of death’ in Latin. As the name suggest, rigor mortis is the process in which a body stiffens after death. During this process, all the muscles in the body contract, and they do not relax for approximately 36 hours.
Three to four hours after death, bodies begin to show signs of rigor mortis, and all muscles are fully contracted after 12 hours. The use of muscles in everyday actions causes the filaments in our muscles to knit together. When we stop using the muscles, the Adenosine triphosphate (the energy within the cell - ATP) helps untangle the filaments. But when someone dies, their body no longer can create ATP, so the muscles are unable to untangle, so they remain contracted. Rigor mortis ends when autolysis (the self-digestion of cells) takes place. Post mortem, the cell digests its own walls, and the muscles break down, meaning they no longer have the strength to remain rigid.