Rigor mortis is best described as?

Rigor mortis is best described as?

• A. The stiffening of the body after death.
• B. The cooling of the body to ambient temperature.
• C. The pooling of blood on the dependent areas.
• D. The decomposition due to microbial activity.

Answer: (A)

Rigor mortis is the stiffening of the body after death caused by biochemical changes in the muscles when ATP is no longer available. After death, muscles can no longer release the actin-myosin cross-bridges, so they remain contracted. Calcium ions also accumulate in muscle cells, promoting sustained contraction. This rigidity typically starts in small muscles like the jaw and neck a few hours after death, then progresses to the rest of the body, usually becoming fully rigid within about 12 hours and fading after roughly 24–48 hours as decomposition advances, with the timing affected by temperature. It’s distinct from algor mortis (cooling of the body), livor mortis (blood pooling in dependent areas), and decomposition driven by microbial activity.

Rigor mortis is the stiffening of the body after death caused by biochemical changes in the muscles when ATP is no longer available. After death, muscles can no longer release the actin-myosin cross-bridges, so they remain contracted. Calcium ions also accumulate in muscle cells, promoting sustained contraction. This rigidity typically starts in small muscles like the jaw and neck a few hours after death, then progresses to the rest of the body, usually becoming fully rigid within about 12 hours and fading after roughly 24–48 hours as decomposition advances, with the timing affected by temperature. It’s distinct from algor mortis (cooling of the body), livor mortis (blood pooling in dependent areas), and decomposition driven by microbial activity.