Rigor mortis that occurs in skeletal muscles a few hours after death is due to
A) excessive ATP and decreased permeability to calcium.
B) decreased ATP and increased permeability to calcium.
C) excessive ATP.
D) lack of oxygen.
E) lactic acid buildup.

Question

Quizplus · Accepted Answer

Rigor mortis occurs due to decreased ATP and increased permeability to calcium in skeletal muscles after death. Without ATP, muscles cannot relax and calcium ions released from the sarcoplasmic reticulum cause the muscle contraction to become permanent. Lactic acid buildup and lack of oxygen can contribute to the process but are not the main cause. Excessive ATP is also unlikely to occur after death.

Rigor Mortis That Occurs in Skeletal Muscles a Few Hours