Postmortem stiffening of body muscles is called?

• A. Rigor mortis
• B. Livor mortis
• C. Algor mortis
• D. Facies Hippocratica

Answer: (A)

Postmortem stiffening of body muscles is called rigor mortis. After death the body's cells stop producing ATP, and calcium leaks into muscle cells, causing actin and myosin filaments to form cross-bridges. Without ATP to detach these bridges, the muscles lock in place, producing a gradual stiffening that starts in small muscles and then involves larger muscle groups. The stiffness typically develops a few hours after death and reaches its peak, then gradually passes as enzymes break down the muscle proteins during decomposition. This is different from livor mortis, which is the settling of blood causing skin discoloration; algor mortis, the body cooling after death; and Facies Hippocratica, a sunken facial appearance seen in some corpses.