Rigor mortis

:"Rigor Mortis" is also the title of a song by Cameo.

Related Topics:
Rigor Mortis - Cameo

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Rigor mortis is a recognizable sign of death that is caused by a chemical change in the muscles, causing the limbs of the corpse to become stiff ("rigor") and impossible to move or manipulate. Assuming mild temperatures, rigor usually sets in about 3-4 hours after clinical death, with full rigor being in effect at about 12 hours, and eventually subsiding to relaxation at about 36 hours. Times for the onset of rigor mortis can vary from a few minutes to several hours depending on the temperature of the environment in which the body is found.

Related Topics:
Death - Muscle - Corpse

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

The biochemical cause of rigor mortis is hydrolysis of ATP in the muscle tissue, the chemical energy source required for movement. Myosin molecules devoid of ATP become permanently adherent to actin filaments to form actomyosin complex and muscles become rigid.After the PH of the muscle has become 5.5, release of autolytic enzymes stored in lysosomes will take place. The major proteolytic enzymes are Cathepsins and Calpains.These enzymes act at the myofibrillar protiens and hydrolyse them. As a result, the actomyosin complex is brocken down and muscles become "soft" again. This is known as resolution of rigor.

Related Topics:
Hydrolysis - ATP - Myosin - Actin - Actomyosin - Lysosomes - Proteolytic - Enzymes - Cathepsins - Calpains - Myofibrillar protiens

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Rigor mortis is of very much importance in meat technology. The onset of rigor mortis and its resolution determines the tenderness of meat. If the post slaughter meat is immedially chilled to 15°C, a phenomenon known as cold shortening occurs, where the muscle is shrunken to 1/3rd of its original size. This will lead to the loss of water from the meat along with much of the vitamins, minerals and water soluble protiens. This will make the meat hard and interefere with the manufacturing of several meat products like cutlet and sausage.

Related Topics:
Meat technology - Meat - Cold shortening - Cutlet - Sausage

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Cold shortening is due to the release of stored Calcium ions from the sarcoplasmic reticulam of muscle fibres in response to the cold stimulus. The Calcium ions trigger powerful muscle contraction aided by ATP molecules.To prevent cold shortening, a process known as electrical stimulation is carried out, espicially in beef carcass immediately after slaughter and flaying. Here, the carcass is stimulated to contract and relax using alternating current. The contraction and relaxation of muscle depletes the ATP reserve from the carcass, thereby preventing cold shortening.

Related Topics:
Calcium - Sarcoplasmic reticulam - ATP - Slaughter

~ ~ ~ ~ ~ ~ ~ ~ ~ ~