Question

Rigor mortis is due to

• A. Leakage of calcium out of the sarcoplasmic reticulum after death
• B. lack of ATP
• C. death of the motor neuron
• D. loss of electrical potential difference across the sarcolemma.

Answer 1

The correct option is B lack of ATP

Rigor mortis is one of the recognizable signs of death, caused by chemical changes in the muscles after death. causing the body to stiffen and locked in place, making it difficult to move.
It begins after about 3 to 4 hours of death, reaches maximum stiffness in 12 hours.
After death, respiration in an organism ceases, depleting the source of oxygen used in the making of ATP. ATP is required to cause separation of the actin-myosin cross-bridges during relaxation of the muscle. When oxygen is no longer present, the body may continue to produce ATP via anaerobic glycolysis. When the body's glycogen is depleted, the ATP concentration diminishes, and the body enters rigor mortis because it is unable to break those actin-myosin cross bridges.
So, the correct option is 'Lack of ATP'.