What is the term for the stiffening of body muscles, which serves as a definitive sign of death?

Rigor mortis refers to the postmortem stiffening of the skeletal muscles, which occurs due to biochemical processes after death. This phenomenon is caused by the depletion of adenosine triphosphate (ATP) in muscle cells, which is necessary for muscle relaxation. As the body’s metabolism ceases, the muscles contract and become rigid, leading to the stiffness characteristic of rigor mortis.

This process typically begins a few hours after death and can last for several days, depending on environmental conditions and the individual’s physical state prior to death. Rigor mortis is an important sign in forensic science and emergency medical situations as it can help determine the time of death, making it a definitive indicator of postmortem changes in the body.

Other terms listed, while related to postmortem processes, describe different phenomena. Cadaveric spasm refers to a sudden and intense stiffening of the muscles that occurs at the moment of death, but does not persist as rigor mortis does. Putrefaction is the process of decomposition primarily caused by bacterial action, leading to the breakdown of tissues, while decomposition is the overall breakdown of organic matter, which includes both biological and chemical processes postmortem. Rigor mortis stands out as the