According to the given order of appearance for rigor mortis, which structure appears second?

According to the given order of appearance for rigor mortis, which structure appears second?

• A. Jaws
• B. Muscles of the eyes
• C. Chest
• D. Face and neck muscles

Answer: (B)

Rigor mortis appears in a specific order because different muscle groups deplete ATP at different rates after death, and smaller, highly active muscles tend to stiffen earlier than larger ones. The jaw muscles are typically among the first to rigidify due to their constant activity and rapid energy use while life ends. The muscles of the eyes are next because they’re small, fast-contracting muscles with high metabolic demand, so they run out of ATP quickly and stiffen soon after the jaw. Larger muscle groups, like chest muscles, and then the face and neck muscles, tend to stiffen later as rigor spreads to bigger, less immediately active muscles. So the second structure to show rigor mortis is the muscles of the eyes.

Rigor mortis appears in a specific order because different muscle groups deplete ATP at different rates after death, and smaller, highly active muscles tend to stiffen earlier than larger ones. The jaw muscles are typically among the first to rigidify due to their constant activity and rapid energy use while life ends. The muscles of the eyes are next because they’re small, fast-contracting muscles with high metabolic demand, so they run out of ATP quickly and stiffen soon after the jaw. Larger muscle groups, like chest muscles, and then the face and neck muscles, tend to stiffen later as rigor spreads to bigger, less immediately active muscles. So the second structure to show rigor mortis is the muscles of the eyes.