What is Rigor Mortis?
Rigor mortis refers to the state of a body after death, in which the muscles become stiff. It commences after around 3 hours, reaching maximum stiffness after 12 hours, and gradually dissipates until approximately 72 hours after death. Rigor mortis occurs due to changes in the physiology of muscles when aerobic respiration ceases. Muscles are made up of two types of fibre. These fibres have connections between them that lock and unlock during muscle contraction and relaxation. These connections are controlled by a biochemical pathway within the cell, which is partially driven by the presence of calcium ions. The concentration of calcium ions is higher in the fluid surrounding muscle cells than it is inside the cells, so calcium tends to diffuse into the cell. High calcium levels inside the cell drive the biochemical pathway in the direction that maintains muscle contraction. To relax, muscle cells must expel the calcium ions from the cell and this requires energy molecules to pump them
Rigor mortis is a condition that begins to develop in the body after death takes place. Essentially, the action of rigor mortis is to begin a process where the muscles in the body begin to stiffen. In most situations, the corpse will begin to undergo the process of rigor mortis at roughly three hours after death takes place and will continue to experience the muscle stiffening for anywhere from thirty-six to seventy-two hours. Rigor mortis takes place due to the fact that once a living entity is dead, there is no longer a steady flow of adenosine triphosphate or ATP flowing into the muscles. ATP is required to help the muscles release from the state of contraction that is caused by the presence of calcium ions that flow into the muscles and act as a bridge or connection between the actin and myosin that is present in the muscle fiber. With no ATP to initiate a release of that connection, the muscles continue to contract, making the dead body go rigid. It is only when the fibers in the
