Post moem stiffening is called: March 2005
**Core Concept**
Post-mortem stiffening, also known as rigor mortis, is a temporary rigidity of the muscles that occurs after death due to a complex interplay of biochemical and mechanical changes. This phenomenon is a result of the cessation of ATP production and the subsequent depletion of energy stores in the muscle cells, leading to an imbalance between the actin and myosin filaments.
**Why the Correct Answer is Right**
Rigor mortis develops within 2-4 hours after death, peaks at around 12 hours, and resolves after 24-72 hours. This process is mediated by the breakdown of ATP, which is essential for the relaxation of muscle fibers. As the ATP stores are depleted, the actin and myosin filaments become locked in a rigid state, resulting in the characteristic stiffness of rigor mortis. The onset and resolution of rigor mortis are influenced by factors such as temperature, the integrity of the muscle cells, and the presence of putrefaction.
**Why Each Wrong Option is Incorrect**
**Option A:** Putrefaction refers to the process of decomposition and breakdown of tissues after death, which is a separate phenomenon from post-mortem stiffening. While putrefaction can occur concurrently with rigor mortis, they are distinct processes.
**Option C:** Livor mortis, also known as hypostasis, is the discoloration of the skin due to the pooling of blood in the dependent areas after death. It is not related to the stiffness of the muscles.
**Option D:** Mummification is a process of desiccation and preservation of the body, often seen in dry environments. It is not a phenomenon related to post-mortem stiffening.
**Clinical Pearl / High-Yield Fact**
Rigor mortis can be a useful indicator of the time elapsed since death, but it is not always reliable due to variations in temperature, body position, and the presence of underlying medical conditions. It is essential to consider other factors, such as livor mortis and algor mortis (the cooling of the body), to estimate the post-mortem interval accurately.
✓ Correct Answer: B. Rigor mortis