Question

Rigor mortis is what type of finding in a deceased​ person?

A. A cardiac condition.
B. A liver disorder.
C. The stiffening of a dead body.
D. A poor circulatory disease.

Answer 1

Rigor mortis is the post-mortem stiffening of muscles due to myosin heads not detaching from actin, leading to stiffening of the dead body, which is unlike muscle processes in the living.

Step-by-step explanation:

Rigor mortis is the biological phenomenon involving the stiffening of a dead body due to chemical changes in the muscles post mortem. After death, the body undergoes a process whereby myosin heads will not detach from the actin-binding sites, leading to muscle stiffness. This is a direct contrast to the process that happens during life when muscle contraction and relaxation are part of normal physiology, with myosin heads attaching and detaching from actin to facilitate this. In a live person, persistent muscle contraction without relaxation can lead to conditions such as "writer's cramp", but it does not cause rigor mortis. Rigor mortis is a key sign noted during post-mortem examinations that commences a few hours after death and can last up to 72 hours.