What is rigor mortis?

Rigor mortis refers specifically to the post-mortem process in which the muscles of a deceased animal undergo a biochemical change that causes them to become stiff and lock into place. This phenomenon occurs after death due to the depletion of ATP (adenosine triphosphate), which is necessary for muscle relaxation. As ATP levels drop, muscle fibers can no longer detach, leading to the characteristic rigidity associated with rigor mortis.

This process typically starts within a few hours post-mortem and can last for several hours to a couple of days, depending on factors such as temperature and the size of the animal. Understanding rigor mortis is significant in meat processing and quality control, as it affects the texture and tenderness of the meat. In contrast, the other options describe different processes or states that do not accurately characterize rigor mortis itself.