American Board of Medicolegal Death Investigators (ABMDI) Practice Exam

Which cardinal sign of death refers to the stiffness of the body?

1. Livor mortis

2. Rigor mortis

3. Absence of heartbeat

4. Body coolness

The correct answer is: Rigor mortis

The stiffness of the body after death is referred to as rigor mortis. This phenomenon occurs due to biochemical changes in the muscle tissue, leading to a temporary stiffening of the muscles. Rigor mortis typically begins a few hours after death and can last for several days before the body begins to relax again. Understanding rigor mortis is crucial for forensic investigators as it can provide valuable information about the time of death and the circumstances surrounding the death. In contrast, livor mortis is the pooling of blood due to gravity, leading to a discoloration of the skin, while the absence of heartbeat indicates the immediate cessation of circulatory functions. Body coolness refers to the process of algor mortis, which is the cooling of the body after death. Each of these signs serves a different purpose in determining time of death and assessing the post-mortem state of the body, but rigor mortis specifically relates to the stiffness observed in the muscles.