Which statement correctly pairs pH values with rigor mortis and advanced decomposition?

Which statement correctly pairs pH values with rigor mortis and advanced decomposition?

• A. Rigor mortis 5-6; advanced decomposition 10-14
• B. Rigor mortis 10-14; advanced decomposition 5-6
• C. Both around pH 7
• D. Advanced decomposition is acidic pH 3-4

Answer: (A)

Postmortem pH changes reflect metabolic activity after death. Early on, cells keep glycolysis going in the absence of oxygen, producing lactic acid and driving the tissue pH down toward acidic values. Rigor mortis occurs during this acidic window, so the pH is around 5–6. As decomposition advances, microbial putrefaction generates basic compounds such as ammonia and amines, pushing the pH upward into strongly alkaline ranges. In advanced decomposition, the pH can climb to about 10–14. So the correct pairing is rigor mortis with a pH of about 5–6, and advanced decomposition with a pH around 10–14. The other options don’t fit this progression because rigor mortis is not associated with high pH, and advanced decomposition is not acidic.

Postmortem pH changes reflect metabolic activity after death. Early on, cells keep glycolysis going in the absence of oxygen, producing lactic acid and driving the tissue pH down toward acidic values. Rigor mortis occurs during this acidic window, so the pH is around 5–6. As decomposition advances, microbial putrefaction generates basic compounds such as ammonia and amines, pushing the pH upward into strongly alkaline ranges. In advanced decomposition, the pH can climb to about 10–14. So the correct pairing is rigor mortis with a pH of about 5–6, and advanced decomposition with a pH around 10–14. The other options don’t fit this progression because rigor mortis is not associated with high pH, and advanced decomposition is not acidic.